Publications
| Title | Abstract | Year(sorted ascending) Filter | PMID Filter |
|---|
| [adaptative differential maturation of neurohypophyseal provasotocin in amphibians: presence of hydrin 2(vasotocinyl-glycine) in anura but not in urodela]. | occurrence of hydrin 2 (vasotocinyl-glycine), an intermediate in the provasotocin processing, has been shown in the neurointermediate lobe of the pituitary of semi-aquatic or terrestrial amphibian species belonging to the order anura, namely rana esculenta, r. temporaria, r. pipiens (ranidae), and bufo bufo, b. marinus, b. ictericus (bufonidae). in contrast hydrin 2 appears absent in species belonging to the order urodela, namely the axolotl ambystoma mexicanum (ambystomidae) and the pleurodele ... | 1991 | 1756409 |
| hematological studies on naturally occurring substances. vi. effects of an animal crude drug "chan su" (bufonis venenum) on blood coagulation, platelet aggregation, fibrinolysis system and cytotoxicity. | during the screening test of the animal crude drug "chan su" (chinese name, toad-cake), the venom of bufo bufo gargorizans cantor (bufonidae), on blood coagulation, platelet aggregation, fibrinolysis system and cytotoxicity, the ethyl acetate extract showed promotive action on platelet aggregation and remarkable cytotoxic activity on hela-s3 cells. nine kinds of bufadienolides were isolated from the ethyl acetate extract by bioactivity-guided fractionation and were identified by chemical and spe ... | 1991 | 1797437 |
| morphological distinction between filaments that converge upon desmosomes and those that are attached to hemidesmosomes in the epidermis of anuran larvae and lampreys. | two populations of morphologically distinct intermediate filaments which are segregated into different compartments of the cytoplasm and which may attach to different junctional specialisations were observed in the basal layer cells of the epidermis of tadpoles of rana catesbeiana, rana temporaria, bufo bufo, leptodactylus flavopictus and pseudis paradoxus and in the skin of the adult lamprey, lampetra planeri. these two distinct populations of cytokeratin intermediate filaments were recognised ... | 1991 | 2050573 |
| [a voltage-dependent potassium channel of outward rectifier type in plasma membrane of oocyte from toad, bufo bufo gargarizans]. | membrane properties of the fully-grown oocytes from toad, bufo bufo gargarizans, were studied by using voltage-clamp technique. it was found that a sustained outward current was elicited by membrane depolarization to -30 mv or more positive value. the increase of the current was nearly proportional to the degree of depolarization. the peak value of the current ranged 2-5 microa at a membrane potential of 20 mv in oocytes from different toads. the current was inhibited by antagonists of potassium ... | 1992 | 1293763 |
| [studies on the chemical constituents from the skin of bufo bufo gargarizans cantor]. | four bufotoxins were isolated by means of preparative reversed phase hplc from the water soluble fraction of the skin of bufo bufo gargarizans cantor. on the basis of their spectral data (uv, ir, 1hnmr, 13cnmr, eims and fdms), amino acid analyses and chemical properties, they were identified as bufotalin 3-succinoylarginine ester(i), bufalin 3-succinoylarginine ester(ii), cinobufagin 3-succinoylarginine ester(iii), and resibufogenin 3-succinoylarginine ester(iv). compound i is a new bufotoxin. | 1992 | 1293940 |
| [the expression of kainate and gaba receptors in oocytes of bufo bufo gargarizans]. | oocytes of bufo bufo gargarizans were used as an expression system for analyzing structure of exogenous membrane protein and their functions. poly (a)+ mrna isolated from rat brain was injected into toad (bufo bufo gargarizans) oocytes (50 ng/oocyte). rat brain kainic acid and gamma-aminobutyric acid(gaba) receptors expressed by the injected mrna were integrated in the oocyte membrane 48 h after the injection at 19 degrees c. membrane currents induced by kainic acid (5 x 10(-5) mol/l) and gaba ( ... | 1992 | 1338132 |
| relationships between feeding, digestion and water balance in a carnivorous vertebrate, the toad bufo bufo l. | 1. toads fed meal worms retained water, amounting to about the mass of the meal. 2. secretion of gastric juice in the initial phase of digestion of a large meal would deplete the extracellular fluid of about half of the chloride ions. 3. ingestion and rapid digestion of large meals in toads and other carnivorous vertebrates imply tolerance of large variations in anion composition and acidity of the extracellular fluid. | 1992 | 1347724 |
| effects of arginine vasotocin, cortisol and adrenergic factors on water balance in the toad bufo bufo: physiology or pharmacology? | 1. the threshold level of exogenous arginine vasotocin (avt) for increasing the cutaneous water permeability in bufo bufo was several times higher than has been measured in dehydrated frogs and toads. 2. the beta-agonist isoproterenol was without effect on water balance in hydrated toads but increased the response to large doses of avt by 25-50%. 3. implantation of cortisol pellets in water-acclimated toads enhanced the cutaneous water permeability by a factor of 2-3. 4. it is concluded that und ... | 1992 | 1351446 |
| beta 2-adrenergic regulation of urea permeability of the bufo bufo bladder. | 1. isoprenaline strongly increases the urea permeability of the bladder of bufo bufo. this effect is due to its interaction with beta 2-adrenoreceptors, activating, in turn, the adenyl cyclase. 2. in order to ensure the regulation of urea permeability, the isoprenaline effect is present even in pathophysiological conditions, inhibiting the vasopressin action. | 1992 | 1354117 |
| effect of breeding state, moulting, dehydration, exposure to saturated atmosphere, and arginine vasotocin on cutaneous water permeability in the toad bufo bufo. | cutaneous water permeability was assessed in hydrated male toads under a variety of conditions, including dehydration and rehydration, and the effects of exogenous arginine vasotocin (avt) were determined. cutaneous water permeability (the rate of water uptake by toads in water) was high in toads collected in the breeding pond and declined steeply during the first week, coincident with reduced activity of the cutaneous mucus glands. the slopes of the dose-response curves relating avt to cutaneou ... | 1992 | 1426963 |
| glutathione transferase isoenzymes from bufo bufo embryos at an early developmental stage. | six forms of glutathione transferase (gst) were resolved from the cytosolic fraction of bufo bufo embryos at developmental stage 4 by gsh-sepharose affinity chromatography followed by f.p.l.c. chromatofocusing in the 9-6 ph range. they have apparent isoelectric points at ph 8.37 (gst i), 8.22 (gst ii), 8.10 (gst iii), 7.84 (gst iv), 7.37 (gst v) and 7.12 (gst vi), and each displayed an apparent subunit molecular mass of 23 kda by sds/page. the bufo bufo embryo enzymes showed very similar structu ... | 1992 | 1567369 |
| configurational pattern discrimination responsible for dishabituation in common toads bufo bufo (l.): behavioral tests of the predictions of a neural model. | recently, a neural model of visual pattern discrimination for stimulus-specific habituation was developed, based on previous behavioral studies which demonstrated that toads exhibit a dishabituation hierarchy for different worm-like stimuli. the model suggests that visual objects are represented by temporal coding and predicts that the dishabituation hierarchy changes when the stimulus/background contrast direction is reversed or the stimulus size is varied. the behavioral experiments reported i ... | 1992 | 1593501 |
| experimental population dynamics of rhabdias bufonis (nematoda) in toads (bufo bufo): density-dependence in the primary infection. | density-dependence in worm establishment, numbers, biomass and larval production were examined in primary infections of 0, 10, 40, 80 and 160 larvae of the lung nematode, rhabdias bufonis in the common toad, bufo bufo. the infection procedure established 4 non-overlapping levels of infection which persisted until 6 weeks post-infection (p.i.), after which there was an overall decline up to 12 weeks p.i. worm numbers had no direct effect on adult worm survival but temporal changes in worm weight ... | 1992 | 1614734 |
| ecg and electrodermal response in rana temporaria and bufo bufo under the influence of autonomic-acting drugs. | 1992 | 1630497 | |
| negative effects of rhabdias bufonis (nematoda) on the growth and survival of toads (bufo bufo). | the growth and survival of juvenile toads, bufo bufo, infected with a common lung nematode, rhabdias bufonis, were studied. toads were raised from tadpoles in the laboratory and infected 2 months after metamorphosis. individual toads were exposed to doses of 10, 40, 80 or 160 larvae, which enabled examination of the hypothesis that parasite-induced mortality is affected by worm numbers. growth of infected toads began to diverge from that of uninfected controls at 6 weeks post infection (wpi) and ... | 1992 | 28312868 |
| testosterone binding sites in the brain, plasma sex hormones and reproductive behaviour in males of the toad bufo bufo. | the central action of steroid hormones of the regulation of reproductive behaviour has been recognized in amphibia, as in, other vertebrates. central and peripheral endocrine aspects of reproductive behaviour were studied in the toad bufo bufo during the breeding aspects of reproductive behaviour were studied in the toad bufo bufo during the breeding (dht) and estradiol (e) levels. in the first experiment the effect of early and late entrance into the breeding pond and the difference between ani ... | 1993 | 24896714 |
| effects of feeding on water balance and cutaneous drinking in the toad (bufo bufo l.). | 1. toads fed mealworms ad libitum for 24-hr periods once a week retained water in the body in amounts that varied with meal size, as well as temporally. 2. the ratio between masses of water retained and mealworms eaten increased from about 0.5 in may to about 1.3 by mid-july, and declined again at the end of the seasonal feeding period. 3. it is argued that this pattern reflects seasonal variation in the secretion of digestive (gastric) juice in response to meal size. 4. the cutaneous drinking r ... | 1993 | 7906637 |
| [experimental analysis of mechanism concerning the environmental temperature effect on acquisition of capability in toad oocyte to resume meiotic division]. | full-grown oocytes derived from bufo bufo gargarizans rearing in high temperature environment (28-30 degrees c), called high temperature oocytes, never underwent germinal vesicle breakdown (gvbd) after progesterone stimulation, no mpf was detected in their ooplasm, but some events which manifested normally at the beginning of progesterone induced maturation process were revealed in these oocytes. it is worth notice an another kind of maturation promoting substance(s) appeared in the ooplasm of h ... | 1993 | 8023639 |
| water-balance response to salt loads in the toad bufo bufo: independence of hypophysial pars nervosa function. | 1. in water, injection of 1 ml of 1 mol/l nacl/100 g body mass increased the rates of cutaneous water uptake and reduced the rates of bladder urine accumulation both in unoperated and sham operated controls and in toads with denervated or extirpated neuro-intermediate lobe. 2. this initial antidiuretic effect of the salt load gradually changed to a diuretic effect, when the volume expansion caused by cutaneous water uptake overrode the effect of increased osmolarity. 3. in a saturated atmosphere ... | 1993 | 8099874 |
| activity trends of adenylate and guanylate cyclases and camp and cgmp levels during the first embryonic stages of bufo bufo. | 1. during the first stages of embryonic development of bufo bufo, the levels of camp and cgmp showed interesting opposite trends analogous to the trends of their respective enzymes. 2. in the late segmentation, the high increase of guanylate cyclase specific activity and the corresponding rise of embryonic level of cgmp, could indicate the involvement of this nucleotide in cellular proliferation. 3. during the following stage of the gastrulation, the increase of adenylate cyclase specific activi ... | 1993 | 8101159 |
| [the chemical interaction of the tadpoles of the common toad (bufo bufo l.) with the tadpoles of other species of anurans inhabiting the same reservoirs]. | chemocommunications of b. bufo tadpoles with those of rana temporaria, r. lessonae, and r. arvalis was investigated. b. bufo tadpoles were shown to be indifferent to conspecific and r. temporaria tadpoles; they escaped heterospecific chemical signals in case of the selection b. bufo: r. lessonae; and they were attracted by those signals in case of the selection water: r. arvalis. these results indicate that b. bufo tadpoles possess differentiated chemosensory perception of the tadpoles of differ ... | 1993 | 8317173 |
| interocular transfer of visual associative memory in toads bufo bufo spinosus. | 1993 | 8336798 | |
| visual performance of the toad (bufo bufo) at low light levels: retinal ganglion cell responses and prey-catching accuracy. | the accuracy of toad snapping towards moving worm dummies under various levels of dim illumination (from absolute threshold to "moonlight") was video-recorded and related to spike responses of retinal ganglion cells exposed to equivalent stimuli. some toads (at ca. 16 degrees c) successfully snapped at dummies that produced only one photoisomerization per 50 rods per second in the retina, in good agreement with thresholds of sensitive retinal ganglion cells. one factor underlying such high sensi ... | 1993 | 8350284 |
| developmental aspects of bufo bufo embryo glutathione transferases. | the expression of glutathione transferase isoenzymes has been studied during the development of bufo bufo embryo. by analysing the gsh-affinity purified materials in terms of substrate specificities, sds-page pattern, hplc elution profile, we conclude that, up to stage 22, no significant changes in the expression of glutathione transferases isoenzymes occurred during bufo bufo embryo development. at stage 25 the distribution of glutathione transferases was found to be slightly different from tho ... | 1993 | 8350663 |
| purification and characterization of the major glutathione transferase from adult toad (bufo bufo) liver. | five forms of glutathione transferase (gst) were resolved from the cytosol of adult common toad (bufo bufo) liver by gsh-affinity chromatography followed by isoelectric focusing. the major enzyme (gst-7.64; 55% of total activity bound to the column) has a pi value of 7.64, is composed of two subunits each with a molecular mass of 23 kda, and has the n-terminal amino acid residue blocked. gst-7.64 has also been characterized with respect to amino acid composition, substrate specificity, inhibitio ... | 1993 | 8424786 |
| ultrastructure of the paraphysis in bufo bufo larvae. | a study of the ultrastructure and function of the paraphysis in bufo bufo larvae was carried out. the structure is a tubular-ramified gland made up of numerous tubules with monolayered epithelial walls surrounded by connective tissue and sinusoids. the epithelial cells secrete glycoprotein to contribute to production of the cephalorachidian fluid. the role of the paraphysis in the transport of fluids and electrolytes from the blood to the cephalorachidian fluid in regulation of ionic and osmotic ... | 1994 | 8114107 |
| lower-field myopia and astigmatism in amphibians and chickens. | in some afoveate vertebrates refractive state appears to vary over the eye to match the average viewing distances of different areas of the visual field. however, precise measurements are difficult to obtain even in anesthetized animals, because standard methods of refraction are not designed for off-axis measurements and because the presence of astigmatism may fog the results. therefore we developed a new automated objective technique, automated infrared photoretinoscopy, and measured off-axis ... | 1994 | 8120697 |
| increases of excitatory receptive fields of retinal ganglion cells in common toads under apomorphine are not associated with size preference in prey-snapping. | after systemic administration of the dopamine agonist apomorphine (apo) in common toads bufo bufo spinosus, the excitatory receptive fields of retinal r2 and r3 ganglion cells doubled their size and the response activities of these neurons to moving visual stimuli were generally increased. comparable investigations of the stimulus-response relationships in the snapping behavior of toads pre- and post-apo showed a general increase in the snapping responses, but no shift in the preferred prey size ... | 1994 | 7936430 |
| comparative analysis of intra- and interpopulation genetic diversity in bufo bufo, using allozyme, single-locus microsatellite, minisatellite, and multilocus minisatellite data. | estimates of genetic diversity within, and of variation among, semi-isolated populations of the common toad (bufo bufo) were derived and compared across four classes of nuclear genetic markers, including allozymes, microsatellites, and single and multilocus minisatellites. estimates of multilocus heterozygosity and the number of alleles per locus derived from allozymes were lower than for each class of variable number of tandem repeat (vntr) markers. the degree of interpopulation genetic diverge ... | 1994 | 7968487 |
| serotonin-degradative pathways in the toad (bufo bufo japonicus) brain: clues to the pharmacological analysis of human psychiatric disorders. | bufotenine (butn) is a hallucinogen with psychotropic effects. high levels of butn and its precursor, n-methylserotonin are shown for the first time to occur and to accumulate mainly in the brain during the degradation of serotonin in the central nervous system of the toad, bufo bufo japonicus. these compounds are concentrated in the hindbrain, which includes the cerebellum and medulla oblongata. butn can also be detected in blood and urine specimens from the toad. in humans, autism is a subtype ... | 1994 | 7749594 |
| the influence of ambient salinity and temperature on lipid metabolism in toad (bufo bufo) skin. is phosphatidylethanolamine an endogenous regulator of ion channels? | incorporation of (32p) phosphate and (14c) acetate into frog (rana temporaria) skin phospholipids in vitro was positively correlated to skin mr cell density. transport across toad (bufo bufo) skin and incorporation into skin phospholipids of the radioactive tracers were independent of transepithelial electrical potential in vitro. while all the incorporations in vitro showed (32p) and (14c) frog and toad skin phospholipid patterns dominated by phosphatidylcholine-independent of adaptational temp ... | 1994 | 7521276 |
| the basis of niche separation during terrestrial life between two species of toad (bufo bufo and bufo calamita): competition or specialisation? | two congeneric anurans with highly overlapping geographical ranges, bufo bufo and b. calamita, were investigated with respect to isolating mechanisms during the terrestrial phase of life in the three habitat types in which both species occur in britain. marked spatial niche separations were observed in all three habitats (coastal dunes, upper saltmarshes and lowland heaths). b. bufo was associated with complex, dense vegetation structures and had a relatively wide niche, while b. calamita had a ... | 1994 | 28313635 |
| the effects of density, rainfall and environmental temperature on body condition and fecundity in the common toad, bufo bufo. | the body length and body weight of all adult common toads (bufo bufo) breeding at a pond in south dorset were measured between 1983 and 1993. each toad was placed into one of four categories depending on its sex and whether it was either a first time breeder or an animal that had previously bred. the body condition of each male and female toad for each year was compared with the average body condition of all the male and female toads captured over the 11 years of the study so that between-year d ... | 1995 | 28306888 |
| excitatory and inhibitory transmission from the optic tectum to nucleus isthmi and its vicinity in amphibians. | intracellular recordings were made from nucleus isthmi (ni) and its vicinity in toads (bufo bufo gargarizans) in response to electrical stimulation of the bilateral optic tract. the results suggest that ni mainly receives its excitatory input from the ipsilateral tectum and its inhibitory input from the contralateral tectum. tegmental cells in a region medioventral to ni were usually characterized by strong spontaneous activity and an excitatory-inhibitory sequence of postsynaptic potentials in ... | 1995 | 7552220 |
| morphogenesis of the pancreas of bufo bufo during metamorphosis. | histology and immunohistochemical reactivity (ir) toward insulin, glucagon, somatostatin14, and pancreatic polypeptide were investigated in the pancreas and in other tissues of bufo bufo during metamorphosis. insulin ir cells appeared at the very beginning of metamorphosis among exocrine pancreatic cells rich in yolk platelets, not completely arranged in acini. less than 1 week later, glucagon, somatostatin14, and pancreatic polypeptide ir cells also appeared. at metamorphic climax, both endocri ... | 1995 | 7622018 |
| echinostoma macrorchis: life history, population dynamics of intramolluscan stages, and the first and second intermediate hosts. | eggs of echinostoma macrorchis were laid at the 1-cell stage and took 9 days (26-27 c) or 6 days (30 c) to hatch. the following accounts are based on studies undertaken at 24-26 c. maximum survival of miracidia was 7 hr. miracidia reached the ventricle of gyraulus chinensis 15-20 hr after penetration and transformed into sporocysts. the earliest degeneration of sporocysts occurred 20 days postinfection (dpi), but some survived for 120 days. mature mother rediac were first seen inside the sporocy ... | 1995 | 7623199 |
| [natural amino acids as effective stimuli evoking chemoreceptor-directed behavior in anuran tadpoles]. | the behavioral reactions of tadpoles of four anuran species, inhabiting moscow region (rana temporaria l., r. lessonae cam., bufo bufo, and pelobates fuscus laur.), on solutions of natural l-amino-acids of different concentrations. it was shown that none of the tadpoles respond to solutions of most amino-acids with concentrations less than 10(-2) mole/l. sequences of relative efficiency of amino-acids as chemical stimuli, inducing feeding behaviour. the sequences display interspecific difference ... | 1995 | 7631525 |
| responses of retinal and tectal neurons in non-paralyzed toads bufo bufo and b. marinus to the real size versus angular size of objects moved at variable distance. | toads judge the real size of moving visual objects during prey-catching. but neither ganglion cells of the retinotectal projection nor tectal neurons showed a comparable phenomenon in muscle paralyzed toads. in non-paralyzed toads, however, tectal neurons, unlike neurons, displayed a sensitivity to the real size of an object moving at variable distance to the animal. interestingly, this property was obtained both in monocular t5 smallfield neurons and in most of the investigated t4 widefield neu ... | 1995 | 7724041 |
| [the chemical interaction of tadpoles of the frog rana arvalis nilss. with conspecific and heterospecific anuran tadpoles]. | in double-choice experiments the tadpoles of rana arvalis were offered chemical cues of con- and heterospecific tadpoles in different combinations. it was shown that they are capable of distinguishing these signals. the cues of bufo bufo and rana lessonae larvae induced a clear reaction of attraction, whereas those of rana temporaria did not cause any visible behavioral response. conspecific tadpoles were more attractive than clear water, irrespective of their relationship with the recipients, h ... | 1995 | 7725786 |
| [the ciliary motility characteristics of the olfactory receptors in the toad bufo bufo]. | 1995 | 7483916 | |
| tissue kinetics, ion transport, and recruitment of mitochondria-rich cells in the skin of the toad (bufo bufo) in response to exposure to distilled water. | mitochondria-rich cells (mrc) of the amphibian epidermis are responsible for active chloride uptake at low external salinity, and new mrcs are recruited in response to exposure to distilled (deionized) water. the time-course of this recruitment, the tissue kinetics and ion transport have been studied in toads (bufo bufo) immediately before, and after 2,7, and 14 days exposure to distilled water. general epidermal structure was not affected. however, the numbers of mrcs per mm2 (dmrc) increased t ... | 1995 | 7750138 |
| [a potentially new sodium channel blocker: 2-chloro-4-bromo-alpha-methylcinnamic acid]. | the effects of 2-chloro-4-bromo-alpha-methylcinnamic acid sodium (sc1001 na) and some channel antagonists on the action potential (ap) and the resting potential (rp) were tested intracellularly in the sartorius muscle of the toad (bufo bufo gargarizans). tea (10mmol/l) and mncl2 (10 mmol/l) had no effect on the amplitude of the ap, otherwise, ttx (1 mumol/l) blocked the ap completely. sc1001 na at the concentration of 2mmol/l largely decreased the amplitude of the ap and expanded the duration of ... | 1995 | 8586392 |
| parasitic disease in amphibians: control by the regulation of worm burdens. | this review considers three case studies based on macroparasites of anurans: (a) natural infections in the permanently-aquatic xenopus laevis which represent the worm burdens acquired, and the implications for pathology, when hosts are exposed to continuous, year-round, transmission; (b) the desert toad, scaphiopus couchii, which experiences invasion very briefly each year and provides a simplified system involving only a single significant infection (pseudodiplorchis americanus); (c) the mesic ... | 1995 | 8632921 |
| ultrasonography characterization of heart morphology and blood flow of lower vertebrates. | echocardiography is an noninvasive technique that utilizes high frequency ultrasound to evaluate structural, functional, and hemodynamic status of the cardiovascular system. with all the inherent potentials of this technique, its application has not been explored on lower vertebrates. the objective of our work was to apply ultrasonography technique, with an available commercial equipment (echo camera--aloka ssd 830 and toshiba using probes of 5 and 7.5 mhz frequency emission) and to identify and ... | 1996 | 8676099 |
| disproportionate distribution of field potentials across the toad's tectal visual map in response to diffuse light on and off stimulations. | in toads bufo marinus and bufo bufo spinosus, field potentials (fps) were recorded from the surface of the optic tectum at different sites of the visual map in response to a sudden diffuse darkening (off) and lightening (on) of the visual field of the contralateral eye. the off and on responses were differently pronounced or even failed to occur. the latency of the former was significantly less than the one of the latter. fp amplitudes of the off and on responses were strongest in the representa ... | 1996 | 8746239 |
| [skeletochronological study in bufo bufo in brittany]. | this study on common toad (bufo bufo), demonstrates the identity of structure between femur and phalange of a same individual. that allowed us to use skeletochronology without killing animals, and to study the same population. the periodicity of the lines of arrested growth (lag) is annual. the absolute age is determined in 96.2% of males and 87.8% of females. the endosteal resorption shows a sexual dimorphism, more important for females. the highest longevity recorded in the sample is 12 years ... | 1996 | 8762979 |
| local effects of glycinergic inhibition in the spinal cord motor systems for swimming in amphibian embryos. | 1. we have studied the effects of locally applying the glycinergic antagonist strychnine to rhythmically active spinal neurons in amphibian embryos during fictive swimming. intracellular recordings were made from motoneurons and premotor interneurons in xenopus laevis, a well-studied model system, and from motoneurons in three other species (rana temporaria, bufo bufo, and triturus vulgaris). overall, these embryos cover a range of swimming patterns from the short-cycle-period, brief-motor-root ... | 1996 | 8871217 |
| a novel antimicrobial peptide from bufo bufo gargarizans. | a potent and structurally novel antimicrobial peptide was isolated and characterized from the stomach tissue of bufo bufo gargarizans, an asian toad. the 39-amino acid peptide, named buforin i, was purified to homogeneity by heparin-affinity column and reverse-phase hplc. the amino acid sequence of buforin i was identical in 37 of 39 amino-terminal residues of xenopus histone h2a. the buforin i showed strong antimicrobial activities in vitro against a broad-spectrum of microorganisms and was fou ... | 1996 | 8573171 |
| [a preliminary study on the hormonal causes of seasonal change in miniature endplate potentials at the neuromuscular junctions of the toad]. | the hormonal causes of seasonal change in amplitudes of miniature endplate potentials (mepp) in the adult toad (bufo bufo gargarizans) were studied with intracellular recordings of mepp at the neuromuscular junction of sartorius muscle fiber in vitro by adding l-thyroxine sodium and estrone to the bath medium during spring and autumn respectively. the results showed that l-thyroxine sodium (50 mumol/ l) could not change the amplitude of mepp, regardless of spring or autumn, but estrone (100 mumo ... | 1996 | 9389005 |
| [seasonal variation and circannual rhythm of miniature end-plate potentials recorded from the neuromuscular junctions of the adult toad (bufo bufo gargarizans)]. | the seasonal variations and circannual rhythm of miniature end-plate potentials (mepp) recorded from the sartorius neuromuscular junctions (nmj) of 66 female and 62 male adult toads (bufo bufo gargarizans) were studied with intracellular microelectrode recording techniques of electrophysiology. the results revealed that the mean amplitude of mepp in each month of a year showed clear seasonal variation with a nadir in september and october and a zenith in march and april. this seasonal variation ... | 1996 | 9389034 |
| [blocking effects of benzyltetrahydropalmatine on delayed rectified k+ currents expressed in xenopus oocytes and in toad oocytes]. | the effects of benzyltetrahydropalmatine (bthp) on delayed rectified k+ currents (ik) expressed in xenopus oocytes and ik of toad (bufo bufo gargarizans) oocytes were studied. the ik expressed in xenopus oocytes was measured after microinjection of mrna isolated from carp fish (c anratus l.) brains with double -microelectrode voltage clamp technique. the maximum and mean value of ik expressed in xenopus oocytes were 600 na and 360 +/- 104 na, respectively. bthp reduced the current amplitude of i ... | 1996 | 9863258 |
| apomorphine-induced suppression of prey oriented turning in toads is correlated with activity changes in pretectum and tectum: [14c]2dg studies and single cell recordings. | in common toads, after systemic administration of the dopamine agonist apomorphine (apo), prey-oriented turning was suppressed. searching for neural correlates, the present study shows apo-induced increases in glucose utilization in the retinorecipient pretectum and dorsal optic tectum and a decrease in the medial tectal output layers. this pattern of metabolic activity is resembled by neuronal discharge activities recorded in response to a prey stimulus; the discharge rates are increased in ret ... | 1996 | 8994231 |
| dopaminergic modulation of visual responses in toads. ii. influences of apomorphine on retinal ganglion cells and tectal cells. | the behavioral studies of part i have shown in common toads that after systemic administration of the dopamine agonist apomorphine the prey-directed orienting turning movements are suppressed while prey snapping is facilitated. part ii focuses on retinal and tectal single cell responses to moving objects. (1) after systemic administration of apomorphine, the discharge rates of retinal class r2 and r3 ganglion cell fibres--recorded from the retino-tectal projection--speeded up in response to visu ... | 1997 | 9008366 |
| [the effects of tripterygium wilfordii polyglycosidium on neuromuscular junctions of adult toad]. | the effects of tripterygium wilfordii polyglycosidium (twp) on the transmission at the neuromuscular junctions (nmj) of sciatic nerve-sartorius muscle preparations of 20 adult toads (bufo bufo gargarizans) in vitro were studied by means of intracellular microelectrode recording of endplate potentials (epp). the results revealed that twp could cause changes of epp amplitude so as to influence the transmission at nmj, and the effects apparently depended on the concentration of the drug. a proper c ... | 1997 | 10683922 |
| [effects of estrone on transmission at neuromuscular junction of the toad]. | the effects of estrone on neuromuscular transmission were studied intracellularly at the muscle fiber endplate in isolated sciatic nerve-sartorius muscle preparations of the toad (bufo bufo gargarizans) in vitro. the results showed that estrone (10(-4) mol/l), added to bath medium, caused an increase in amplitudes of endplate potentials (epp) both in 10 micrograms tubocurarine treated and 10 mmol/l mgcl2 treated preparations, but the increase was more prominent in the former, and that estrone, 3 ... | 1997 | 10684057 |
| lithium secretion in kidneys of amphibians and reptiles under hydrated conditions. | renal lithium transport was studied at different hydration levels in five species of anuran amphibians (bufo bufo, b. danatensis, b. viridis, rana ridibunda, and r. temporaria), two species of urodeles (triturus vulgaris and t. cristatus) and four species of reptiles (lizards eremias multiocellata, lacerta vivipara, trapelus sanguinolentus, and teratoscincus scincus). under dehydration conditions, li+ was reabsorbed in the kidneys of amphibians ans reptiles, but to a lesser degree than in mammal ... | 1997 | 9505431 |
| immunolocation of mitochondria-rich cells in epidermis of the common toad, bufo bufo l. | the mitochondria-rich cells (mrcs) in adult toad epidermis have an important osmoregulatory function, being specialized for chloride transport. immunostaining with monoclonal antibodies against human keratins was used to compare the keratin expressed by mrcs with that of principal cells (pcs). by the indirect immunoperoxidase technique, keratin epitopes in vertical cryosections (4-6 microns) of toad skin were labelled and examined by light microscopy. mrcs were stained selectively by the antibod ... | 1997 | 9440221 |
| structural analysis of hexa to dodecaoligosaccharide-alditols released by reductive beta-elimination from oviducal mucins of bufo bufo. | hexa to dodecasaccharide-alditols of the jelly coat surrounding the eggs of the toad bufo bufo were studied by methylation analysis, maldi-tof mass spectrometry, and h-nmr spectroscopy. these highly species-specific carbohydrate chains exhibit new structural features, such as the elongation of the blood group a determinant with an external alpha-1,3-linked galactose unit, or ramification belonging from a fucosylated galactose. the most representative oligosaccharide-alditol of the series was def ... | 1997 | 9455914 |
| nitric oxide production by cells infiltrating amphibian skin grafts. | in vivo injection of the edible frog rana esculenta with nos inhibitor, l-nmma caused prolongation of skin allograft and xenograft viability, statistically significant only in the latter case. in the present studies skin allo- and xenografts at the latent or rejection phase were excised from the hosts (bufo bufo, r. temporaria, and r. esculenta) and incubated in vitro for 24 hrs in a medium only or in the presence of competitive (l-nmma, l-name, l-aminoguanidyne) and noncompetitive (dexamethason ... | 1997 | 9557139 |
| dopaminergic modulation of visual responses in toads. i. apomorphine-induced effects on visually directed appetitive and consummatory prey-catching behavior. | this study confirms for a phylogenetically basal terrestrial vertebrate that dopaminergic modulations interfere with the visually directed appetitive and consummatory feeding behaviors orienting and snapping, respectively. (1) in common toads bufo bufo, intralymphatic administration of the dopamine d2/d1-receptor agonist apomorphine led to a dose-dependent facilitation of prey-snapping in response to moving objects. the snapping activity reached a maximum 15-35 min after apomorphine injection. ( ... | 1997 | 9008365 |
| lethal and sublethal effects of nitrogen fertilizer ammonium nitrate oncommon toad (bufo bufo) tadpoles | the impact of elevated ammonium nitrate concentrations onthe survival and development of common toad (bufo bufo) tadpoles wasinvestigated in the laboratory. 1,704 mg/l and 1,637 mg/l nitrate (equivalentto 2,198.7 mg/l and 2,112.3 mg/l ammonium nitrate) were recorded as 96 h and168 h lc50s respectively. these are well above field levels (10-250 mg/l)observed in freshwater in britain. the exposure of tadpoles to nominalconcentration of 100 mg/l nitrate for 24, 48, and 72 h caused a significantdecr ... | 1997 | 9096079 |
| identification of anion-selective channels in the basolateral membrane of mitochondria-rich epithelial cells. | epithelial cells of toad (bufo bufo) skin were isolated by treatments of the epidermis with collagenase and trypsin. cl- channels in the basolateral membrane from soma or neck of mitochondria-rich cells were studied in cell-attached and excised inside-out configurations. of a total of 87 sealed patches only 28 (32%) were electrically active, and in these we identified four different types of cl- channels. the two major populations constituted ohmic cl- channels with limiting conductance (gamma12 ... | 1997 | 9178613 |
| the metabolism of biogenic monoamines during embryogenesis and metamorphosis in two anuran species. | this study investigated the pathways to many monoamines and their metabolites in the central nervous system of the frog rana nigromaculata and the toad bufo bufo japonicus during embryonic development and metamorphosis. metabolites were analyzed by three-dimensional hplc. the two species provided evidence of similar pathways, with slightly different timetables for the development of their monoamine systems. during embryonic development, the main metabolic pathways in entire embryos were tyrosine ... | 1997 | 9204370 |
| effective number of breeding adults in bufo bufo estimated from age-specific variation at minisatellite loci. | estimates of the effective number of breeding adults were derived for three semi-isolated populations of the common toad bufo bufo based on temporal (i.e. adult-progeny) variance in allele frequency for three highly polymorphic minisatellite loci. estimates of spatial variance in allele frequency among populations and of age-specific measures of genetic variability are also described. each population was characterized by a low effective adult breeding number (nb) based on a large age-specific va ... | 1997 | 9262012 |
| coexistence of alpha1 and beta adrenergic receptors in the liver of the frog rana esculenta, the toad bufo bufo, the lizard podarcis sicula campestris, and the turtle pseudemys picta elegans. | in mammals and birds the characteristics of alpha1 adrenergic receptors and their biological role in liver metabolism have been clearly described, although the predominance of receptor subtypes varies with species. in contrast, the actual presence of hepatic alpha1 adrenergic receptors in fish, amphibians, and reptiles has been questioned. only recently has their existence been demonstrated in some fish species and also in the wood frog rana sylvatica. the present study assessed the presence of ... | 1997 | 9268616 |
| toad tadpole aggregation behaviour: evidence for a predator avoidance function | two sets of experiments were conducted to determine whether aggregation behaviour, commonly observed in tadpoles of the common toad, bufo bufohad a predator avoidance function. in the first set of experiments, the distribution of toad tadpoles, of single or mixed sibship, was monitored in large artificial pools, one with fish chemical cues and one without. aggregation behaviour was determined on the basis of the distribution of the tadpoles under these treatments by using two indices of cohesion ... | 1997 | 9344439 |
| structural analysis of oligosaccharide-alditols released by reductive beta-elimination from oviducal mucins of bufo bufo: characterization of the carbohydrate sequence gal(alpha1-3)galnac(alpha1-3)[fuc(alpha1-2)]gal. | several tri- to hexasaccharide-alditols of the jelly coat surrounding the eggs of bufo bufo were studied by methylation analysis, maldi-tof mass spectrometry, and 1h-nmr spectroscopy. as observed for six other amphibian species, these carbohydrate chains are highly species-specific. the main characteristics of the species bufo bufo consists in the presence of the new carbohydrate sequence gal(alpha1-3)galnac(alpha1-3)[fuc(alpha1-2)]gal, in which a blood group a determinant is substituted with an ... | 1997 | 9376680 |
| pawedness and motor asymmetries in toads. | pawedness was investigated in three species of toads, bufo bufo , bufo viridis , and bufo marinus. samples from natural populations were collected in two successive years and tested during attempts to remove a strip of paper stuck onto the snout ( bufo bufo and bufo viridis ) or during attempts to remove an elastic balloon wrapped around the head ( bufo bufo ). a preferential right forelimb use at the population level was observed in bufo bufo in both tests, whereas no clear pawedness was observ ... | 1997 | 15513053 |
| temperature but not season affects the transplantation immunity of anuran amphibians. | the effects of ambient temperature (22 degrees c/10 degrees c) and season (summer/winter) on anuran skin allograft and xenograft rejection was tested in frogs (rana temporaria and r. esculenta) and toads (bufo bufo, bombina variegata, and bombina bombina). mean graft survival times were significantly prolonged at the low temperature in a species-specific manner, the edible frog (r. esculenta) being the most sensitive and the common toad (bufo bufo) relatively resistant. allografts were more temp ... | 1998 | 9571769 |
| glyoxalases activity during bufo bufo embryo development. | in this work we have investigated the expression of glyoxalase i (glo i) and glyoxalase ii (glo ii) activities during bufo bufo embryo development and in some tissues of both male and female adult animals, in order to study how they correlate with cell proliferation and differentiation. the results show that both the activities are expressed at significant levels from the earliest developmental stages, reaching the highest values at the end of embryonic development (stage 25). the glo i/glo ii r ... | 1998 | 9578114 |
| spatial distribution of yolk platelets and fat droplets in oocytes and cleaving embryos of the common frog (rana temporaria) and toad (bufo bufo). | animal-vegetal gradients of fat droplets and yolk platelets have been quantitatively determined in mature oocytes and in cleaving embryos in two anuran species rana temporaria and bufo bufo using stereological methods. volume densities vv which describe properly the amount of nutrients in embryos have been used during the measurements. the embryos till the stage of late blastula are spherical: the spherical form is not distorted even by blastocoel forming eccentrically, in the animal hemisphere. ... | 1998 | 9606623 |
| [ultrastructural organization of cardiomyocytes in various lower vertebrates]. | electron microscopy was used to study myocardium in cyprinus carpio, bufo bufo and lacerta agilis. myofibrils, mitochondria, nuclei and secretory granules in cardiomyocytes (cmc) of atrium and ventricle were analyzed quantitatively. amphibians and reptiles showed significant complication of both structural organization of cmc and intercellular contacts versus bony fish. the absence of t-systems in bony fish was noted. | 1998 | 9621323 |
| antimicrobial peptides derived from pepsinogens in the stomach of the bullfrog, rana catesbeiana. | three antimicrobial peptides, which had strong antimicrobial activity against a broad spectrum of microorganisms, were isolated from the stomach of the bullfrog, rana catesbeiana. two of the antimicrobial peptides were found to be derived from the n-terminal sequences of pepsinogen a and c prosequences. the amino acid sequences of the new antimicrobial peptides, named bullfrog pepsinogen a-derived antimicrobial peptide (bpaap) and bullfrog pepsinogen c-derived antimicrobial peptide (bpcap), were ... | 1998 | 9639668 |
| pancreatic endocrine cells in bufo bufo: immunocytochemistry and ultrastructure. | the endocrine pancreas of the toad consists of rounded islets of various sizes embedded in the exocrine tissue. isolated cells are also present. at least 4 types of endocrine cell are distinguishable by shape, size and electrondensity of the secretory granules as well as by their immunoreactivity with different antisera: insulin, somatostatin, pancreatic polypeptide, and glucagon cells. insulin cells can be divided into 2 types according to their cytoplasmic electrondensity. colocalisation of di ... | 1998 | 9643420 |
| [study of amphibian brain asymmetry during normal embryonic and larval development]. | amphibian embryos (triturus vulgaris, pleurodeles waltl, hynobius keyserlingii, ambystoma mexicanum, rana temporaria, bufo bufo, and xenopus laevis) were investigated. we ascertained the morphological right-side asymmetry of the brain, which appears at the neurula stage and is preserved during the postembryonic (larval) development. in t. vulgaris, p. waltl, h. keyserlingii, and x. laevis, we observed right-side asymmetry of peripheral analyzers, such as the retina, ganglia of nerve viii, and ol ... | 1998 | 9644914 |
| effects of methanol extract of chansu on hypothalamic-pituitary-testis function in rats. | chansu, a galenical preparation of the dried white venom of chinese bufo bufo gargarizans, is one of the major components of kyushin, a traditional chinese medicine. kyushin is reported to have a cardiotonic effect that has been suggested to be due to the action of bufadienolides such as bufalin and cinobufagin. recently, we found that administration of bufalin in male rats diminished the luteinizing hormone (lh) response to gonadotropin-releasing hormone (gnrh) and the secretion of testosterone ... | 1998 | 9781623 |
| tegmental inhibition on isthmic neurons is mediated by the decussatio veli in amphibians. | this in vitro study on toads (bufo bufo gargarizans) provides the first electrophysiological evidence that electrical stimulation of the decussatio veli in the midbrain tegmentum predominantly produced inhibition on neurons extracellularly recorded from the nucleus isthmi (ni). these cells were distributed throughout the nucleus. the present study lends strong support to the suggestion that the extratectal input to ni is mainly inhibitory and gives a good explanation for the previously reported ... | 1998 | 9785351 |
| lateralized agonistic responses and hindlimb use in toads. | the recent discovery of forepaw preferences (handedness) in toad species has provided some insight into the evolution of brain lateralization. we tested the prediction that, as in higher vertebrates, visual lateralization and other motor preferences (footedness) also exists in toad species. during feeding periods, south american cane toads, bufo marinus, showed a population bias to strike with the tongue at other toads occupying their left visual field. this is the first demonstration of lateral ... | 1998 | 9790698 |
| effects of food, glucose, and water ingestion on feeding activity in the toad (bufo bufo). | feeding in toads was tested by orient, approach, fixate, and snap responses to an artificial prey stimulus, before and at various times after feeding with natural prey (mealworms), or infusion of the gut with a prey-equivalent amount of glucose or volume of water. feeding 5 prey objects or ad libitum feeding caused a decline in a prey catching when tested 2 hr later. ingestion of 5 pulped mealworms or the equivalent glucose content and volume similarly decreased prey-catching, though an equal vo ... | 1998 | 9829804 |
| effect of methylglyoxal on bufo bufo embryo development: morphological and biochemical aspects. | methylglyoxal (2-oxopropanal) is a cytotoxic compound that can be formed endogenously as a by-product of glycolytic pathway; so its concentration is expected to increase when glycolysis activity increases such as during embryo development. in this work we study the effect of exogenous methylglyoxal on development and embryo viability during bufo bufo development and on the enzymes and cofactors involved in its detoxication process (glyoxalase i and ii, reduced glutathione and glyceraldehyde 3-ph ... | 1998 | 9839630 |
| the effects of aromatase and 5 alpha-reductase inhibitors, antiandrogen, and sex steroids on bidder's organs development and gonadal differentiation in bufo bufo tadpoles. | embryos of toads (bufo bufo) were treated with aromatase (4-oha) and 5 alpha-reductase (17 beta c) inhibitors, antiandrogen (cpa), estradiol-17 beta, testosterone, and 5 alpha-dihydrotestosterone in order to study the role played by sex steroids in the development and sex differentiation of gonads. test compounds were administered to tadpoles in water and morphometric and cytometric analyses were carried out on histological sections of the cephalic bidder's organ (a rudimentary ovary) and of the ... | 1998 | 9472481 |
| acidic peptide-mediated expression of the antimicrobial peptide buforin ii as tandem repeats in escherichia coli. | antimicrobial peptides have received increasing attention as a new pharmaceutical substance, because of their broad spectrum of antimicrobial activities and the rapid development of multidrug-resistant pathogenic microorganisms. the main obstacle to the wide application of antimicrobial peptides has been the lack of a cost-effective, mass-production method. a novel mass-production method for an antimicrobial peptide of 21 amino acids, buforin ii, which was isolated from the stomach of the amphib ... | 1998 | 9473457 |
| phylogenetic relationships of toads in the bufo bufo species group from the eastern escarpment of the tibetan plateau: a case of vicariance and dispersal. | phylogenetic relationships among tibetan populations of the bufo bufo species group are investigated using 1063 bases of mitochondrial dna sequence from the genes encoding nd1 (subunit one of nadh dehydrogenase), trna(ile), trna(gln), trna(met), and nd2. the aligned sequences contain 181 phylogenetically informative characters across all taxa sampled. two hypotheses for colonization of the tibetan plateau are tested. a vicariant hypothesis predicts monophyly of populations from high elevations. ... | 1998 | 9479697 |
| scanning electron microscopy of the egg surface of the common toad, bufo bufo, following fertilization and during first cleavage. | scanning electron microscopy was applied for surface analysis of unfertilized and fertilized eggs of the common toad, bufo bufo. in unfertilized eggs two types of surface protrusions were found: microvilli and microfolds. 5 min post fertilization (pf), at the place of sperm entrance, a fertilization body appears, surrounded by a group of small depressions, which gradually spread over the whole egg surface. this phenomenon is considered to reflect structural changes of the egg membrane, occurring ... | 1998 | 9527022 |
| rhodopsins from three frog and toad species: sequences and functional comparisons. | the frequency of thermal 'dark events' in the membrane current of rhodopsin rods of the bullfrog, rana catesbeiana, is considerably lower than observed in rods of two toad species, even though all three rhodopsins have approximately the same absorbance characteristics. in order to map amino acid substitutions possibly associated with thermal stability in the genus rana, the cdna's coding for the rhodopsins of bufo bufo, b. marinus and r. temporaria were sequenced and the conceptually translated ... | 1998 | 9533857 |
| rod pigment and rod noise in the european toad bufo bufo. | behavioural experiments and ganglion cell recordings indicate that the visual sensitivity of dark-adapted toads is limited by the occurrence of spontaneous isomerization-like noise events in the rods. the frequency of these "false photons" has previously been studied (with micropipette recording) in the toad species bufo marinus, while the behavioural thresholds were determined using bufo bufo toads. thus, it was necessary to check that the noise event frequency is roughly the same in these two ... | 1998 | 9536371 |
| isolation of the o-glycosidically linked oligosaccharides obtained by alkaline borohydride degradation from oviducal mucins of the toad bufo bufo. | a combination of normal-phase high-performance liquid chromatography (hplc) on amino-bonded silica and reversed-phase hplc on octadecylsilica has been used to separate the reduced oligosaccharides produced by alkaline borohydride degradation of oviducal mucins obtained from the jelly coat of bufo bufo. the former technique provides suitable separation on the basis of molecular size, while the latter method offers selectivity for stereoisomers. thirty-four compounds, ranging in size from a trisac ... | 1998 | 9544812 |
| anthropogenic mortality of the common toad (bufo bufo) in scotland. | 1998 | 9549869 | |
| cytochemical localization of adenylate cyclase in the limb buds of bufo bufo. | the importance of cyclic nucleotides in the regulation of the processes of differentiation and embryonic development is known. the possible role that cyclic adenosine monophosphate (camp) plays during the development of the posterior limb of bufo bufo is studied by the cytochemical localization of adenylate cyclase (ac), an enzyme that catalyzes the synthesis of the cyclic nucleotide. the method is based on the reaction between the enzyme ac and its specific substrate amp-pnp (5'-adenylylimidodi ... | 1998 | 9551625 |
| the lung of the common toad, bufo arenarum (anura: bufonidae). a light and electron microscopy study. | the present study describes the lung morphology of the common toad, bufo arenarum, as observed by light and electron microscopy. the lung wall consists of four layers: mesothelium, dense connective tissue with thin elastic fibers, loose connective tissue containing smooth muscle fibers and an internal respiratory epithelium. the lung presents three types of folds defined by their epithelia. first order folds are coated by ciliated epithelium containing numerous goblet cells. second order folds p ... | 1998 | 10904523 |
| the effect of winter temperatures on the timing of breeding activity in the common toad bufo bufo. | a 19-year study of a common toad population in south dorset, uk, was carried out between 1980 and 1998. the daily arrival of sexually mature male and female toads at a breeding pond was recorded each year. the timing of the main arrival of toads at the breeding pond was highly correlated with the mean daily temperatures over the 40 days immediately preceding the main arrival. when the temperatures were higher than average, breeding occurred significantly earlier in the year than if they were eit ... | 1998 | 28307671 |
| impacts of climate and density on the duration of the tadpole stage of the common toad bufo bufo. | in an ongoing long-term study of a breeding population of common toads bufo bufo at a pond in southern england, the dates of first spawning have been recorded since 1980, the dates of toadlet emergence since 1984, and the numbers of emergent toadlets estimated since 1988. the dates when spawn was first laid varied considerably between years from the earliest on 2 february 1993 (day 33) to the latest on 19 march 1996 (day 79). the duration of the tadpole stage was negatively correlated with the d ... | 1999 | 28308318 |
| [homoplastic transplantation of ++cloacal elements in anura amphibians (bufo bufo, bufo viridis, rana esculenta)]. | 1999 | 10765671 | |
| apomorphine alters prey-catching patterns in the common toad: behavioral experiments and (14)c-2-deoxyglucose brain mapping studies. | previous studies on the dopaminergic modulation of visuomotor functions in amphibians showed that the dopamine agonist apomorphine (apo) alters prey-catching strategies. after systemic administration of apo in common toads bufo bufo, prey-oriented turning and locomotion was attenuated whereas snapping toward prey was facilitated in a dose dependent manner. with systemic apo administration, toads which had previously been hunting, that is pursuing prey, behaved in a waiting position, that is sitt ... | 1999 | 10592384 |
| predation as a suspected cause of common toad (bufo bufo) mortality incidents in scotland. | 1999 | 10028573 | |
| ampa/kainate receptors permeable to divalent cations in amphibian central nervous system. | glutamate receptors have been studied extensively in mammals but less explored in lower vertebrates. these receptors are present in amphibians. using a recent method based upon agonist-induced cobalt uptake, we were able to detect the presence of functional alpha-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (ampa)/kainate receptors permeable to divalent cations in tadpoles and in adults. the uptake specificity was checked by co-application of an antagonist. we studied the distribution of r ... | 1999 | 10069524 |
| sodium recirculation and isotonic transport in toad small intestine. | isolated small intestine of toad (bufo bufo) was mounted on glass tubes for perfusion studies with oxygenated amphibian ringer's solution containing glucose and acetate. under open-circuit conditions (vt = -3.9 +/- 1.8 mv, n = 14) the preparation generated a net influx of 134cs+. the time course of unidirectional 134cs+-fluxes was mono-exponential with similar rate constants for influx and outflux when measured in the same preparation. the flux-ratio was time invariant from the beginning of appe ... | 1999 | 10191358 |
| characterization of toad liver glutathione transferase. | the major form of glutathione transferase from the toad liver previously designed as bufo bufo liver gst-7.6 (a. aceto, b. dragani, t. bucciarelli, p. sacchetta, f. martini, s. angelucci, f. amicarelli, m. miranda and c. di ilio, biochem. j. 289 (1993) 417-422) has been characterized. according to its partial amino acid sequence, the toad enzyme may be included in the pi class gst and named bbgst p2-2. however, bbgst p2-2 appears to be immunologically, structurally and kinetically distinct from ... | 1999 | 10209291 |
| effects of glutamatergic, cholinergic and gabaergic antagonists on tectal cells in toads. | the present paper using microiontophoresis analysis describes transmitters and their receptor subtypes used in retinotectal and isthmotectal transmission, and suggests several modes converging retinotectal and isthmotectal afferents on tectal neurons in toads (bufo bufo gargarizans). neuronal responses of tectal cells were extracellularly recorded to both visual stimulation and electrical stimulation of the nucleus isthmi, and effects of glutamatergic, cholinergic, gabaergic and glycinergic anta ... | 1999 | 10218805 |
| genetic structure of island populations of the anurans rana temporaria and bufo bufo | amphibians have traditionally been considered to have low dispersal ability and they have become a model for studies on the effects of man-made habitat fragmentation on genetic variation and population differentiation. this study examined the genetic population structure in the common frog (rana temporaria) and the common toad (bufo bufo) in an archipelago of the northern baltic sea. heterozygosity was not correlated with distance of the island from the mainland nor, in r. temporaria, with effec ... | 1999 | 10336706 |