Publications
| Title | Abstract | Year Filter | PMID(sorted ascending) Filter |
|---|
| comparative study of tyrosinases from different sources: relationship between halide inhibition and the enzyme active site. | the inhibition of tyrosinases from frog epidermis (rana esculenta ridibunda), mushroom (agaricus bisporus) and harding-passey mouse melanoma by halides is compared. in all cases, the inhibition is ph dependent, increasing when the ph decreases. the order of inhibition is i- greater than br- greater than cl- much greater than f- for frog epidermis tyrosinase, f- greater than i- greater than cl- greater than br- for mushroom tyrosinase and f- greater than cl- much greater than br- greater than i- ... | 1986 | 3082587 |
| in vivo and in vitro stimulatory effect of a gonadotropin-releasing hormone analog (hoe 766) on spermatogonial multiplication in the frog, rana esculenta. | the effects of a gnrh analog (gnrha), d-ser-t-bu6,desgly-nh2(10) (hoe 766) on spermatogenesis were analyzed in the frog, rana esculenta. intact animals caught at two different periods of the year (january and march) were treated with hoe 766 (gnrha, 45 ng/g bw) at low (4 +/- 1 c) and high (22 +/- 2 c) temperatures. hypophysectomized frogs were used also and, in addition to gnrha, these animals were treated with crude pars distalis homogenate. in vitro incubations were carried out at 15 c, for 0, ... | 1986 | 3089762 |
| variations of intestinal calcium absorption in adult frogs (rana esculenta). effect of lysine. | intestinal calcium absorption was investigated in an adult frog (rana esculenta) by injecting a cacl2 solution containing 45ca into the lumen. the 45ca absorption coefficient in the proximal loop was higher than in the distal loop, only when the cacl2 solution was left for 4 h. this coefficient increased both in the proximal and distal loops when a 4-h treatment was substituted for a 1-h treatment. the coefficient increased in the whole intestine during the first 2 h of treatment (1 h: 21%; 2 h: ... | 1987 | 3108978 |
| prostaglandin e2-stimulated glandular ion and water secretion in isolated frog skin (rana esculenta). | prostaglandins are known to stimulate the active sodium absorption in frog skin. in this paper it is shown that prostaglandin e2 (pge2) stimulates an active secretion of cl-, na+, and k+ from the skin glands in rana esculenta. the active cl secretion is enhanced more than the na and k secretion. therefore, in skins where the na absorption is inhibited by amiloride, the addition of pge2 results in an increase in the short-circuit current (scc). the pge2-stimulated cl secretion could be inhibited ... | 1987 | 3112408 |
| action of tocainide and mexiletine on the excitation threshold of myelinated nerves. | the antiarrhythmic drugs tocainide and mexiletine increase the excitation threshold and decrease the na permeability (pna) in nerves. hodgkin-huxley model calculations suggest that the pna decrease is not sufficient to explain the threshold increase at low concentrations (less than 0.7 mm tocainide; less than 0.1 mm mexiletine). on the other hand, a drug action on the membrane surface potential would be consistent with results of recent experiments. to clarify this point electrophysiological exp ... | 1987 | 3119354 |
| ultrastructural analysis and cholinesterase activity in the brain capillaries of bufo bufo and rana esculenta. | we have investigated the structure and the cholinesterase features of the brain capillaries in two adult amphibians (rana esculenta and bufo bufo). we found that brain capillaries are un-fenestrated and the endothelial cell edges are joined by tight junctions. the brain capillaries in both species are characterized by high levels of ache. this enzyme is only localized in the basal membrane, whereas we have found the reaction product neither in the endoplasmatic reticulum nor in the golgi apparat ... | 1987 | 3121723 |
| thymosin beta 4xen: a new thymosin beta 4-like peptide in oocytes of xenopus laevis. | two new thymosin beta 4-like peptides have been detected in ovaries of xenopus laevis and rana esculenta. previously, it was reported that thymosin beta 4 can be found in various species, from mammals to amphibians, e.g., in x. laevis [s. erickson-viitanen, s. ruggieri, p. natalini, and b.l. horecker (1983) arch. biochem. biophys. 221, 570-576]. however, oocytes and spleen from r. esculenta contain no thymosin beta 4 but a similar peptide without methionine. the peptide from r. esculenta elutes ... | 1988 | 3124756 |
| preparation and characterization of the major isotype of parvalbumin from skeletal muscle of the toad (bufo bufo japonicus). | the major isotype of parvalbumin has been isolated from the skeletal muscle of the toad, bufo bufo japonicus. unlike the skeletal muscle of every frog so far examined (rana esculenta, rana temporaria, and rana catesbeiana), which contains two major isotypes of parvalbumins, toad skeletal muscle has been shown to contain only one isotype, but the content of parvalbumin in toad skeletal muscle was similar to the sum of those of the two isotypes in skeletal muscles of frogs. this feature of toad sk ... | 1987 | 3125161 |
| two populations of serotonin-immunoreactive neurons in the frog (rana esculenta) retina. | serotonin immunocytochemical staining in retina whole-mounts of rana esculenta revealed two differently stained amacrine cell populations. statistical investigations using nearest neighbor analysis and comparison with different theoretical cell distributions suggested that the two serotonin-immunoreactive cell populations are related to functionally different types. the analysis of type a (intensely stained somata, less numerous) revealed a good coincidence with the normal gaussian distribution ... | 1988 | 3127758 |
| luteinizing hormone-releasing hormone as a potent stimulator of the thyroidal axis in ranid frogs. | plasma concentrations of t4, measured by radioimmunoassay, were raised significantly 2 and 4 hr after intravenous injection of synthetic luteinizing hormone-releasing hormone (lhrh) in rana ridibunda (1 and 10 micrograms on 2 consecutive days) and in rana esculenta (10 micrograms). a dose of 1 microgram lhrh was not so effective as 50 micrograms synthetic thyrotropin-releasing hormone (trh) when injected in rana ridibunda in november. however 10 micrograms lhrh was equipotent to 50 micrograms tr ... | 1988 | 3133281 |
| estradiol-binding molecules in the hepatocytes of the female water frog, rana esculenta, and plasma estradiol and vitellogenin levels during the reproductive cycle. | estradiol-binding molecules have been found both in cytosol and nuclear extract of hepatocytes of the female green frog rana esculenta. these molecules show the properties of an estradiol receptor (re): high and specific affinity for estrogens (2.10-7.10 x 10(-10) m), stability of binding at 0 and 20 degrees, localization in the nucleus, and cytosolic versus nuclear binding shift in estradiol-treated frogs. in hepatocytes, both filled and unfilled re is detectable in all stages of the r. esculen ... | 1988 | 3138158 |
| [demonstration of a tyrosinase type activity in kupffer cells of rana esculenta l]. | 1988 | 3142500 | |
| dihydrofolate reductase activity in the purkinje neuron populations of some non-mammalian vertebrates. | the intensity and distribution of histochemically demonstrable dihydrofolate reductase (fh2-r ec 1.5.1.3.) in unfixed cryostat sections was studied in purkinje neurons of adult vertebrates that have either simple neural circuits and cytoarchitectonics (ictalurus nebulosus, rana esculenta) or complex neural circuits and cytoarchitectonics (coturnix coturnix japonica), compared with the rat as a control. the reaction was generally undetectable in ictalurus nebulosus and in rana esculenta; with pos ... | 1988 | 3149438 |
| estradiol-binding molecules in the liver of the water frog rana esculenta, during the reproductive cycle. | 1988 | 3150625 | |
| sensory cells of the "rod-" and "cone-type" in the pineal organ of rana esculenta, as revealed by immunoreaction against opsin and by the presence of an oil (lipid) droplet. | the pineal organ of the frog, rana esculenta, was studied by use of light- and electron-microscopic methods including immunoreaction against opsin. most of the morphologically classified cone-type outer segments of the pineal photoreceptors reacted with antisera against opsin of the bovine retina that is dominated by rods. some of the outer segments of pineal photoreceptor cells remained unstained in accord with the reference tissue, the frog retina, where generally the rods were opsin-positive ... | 1985 | 3158392 |
| fine structure of the fungiform papilla in a ranid frog (rana esculenta). | the freetop of the fungiform papilla shows a sensorial area about 100 micron in diameter, surrounded by a ring of ciliated cells. externally to the ciliated cells, i.e., in the lateral wall, numerous large goblet cells can be seen devoid of their mucous content. the sensorial area is composed by three types of cells: mucous, supporting, and neuroepithelial cells. mucous cells form the most superficial layer, while the cell bodies of the other two are deep, and from them basal and apical processe ... | 2011 | 3257525 |
| an amphibian two-domain 'big' neurophysin: conformational homology with the mammalian msel-neurophysin/copeptin intermediate precursor shown by trypsin-sepharose proteolysis. | a 'big' frog (rana esculenta) neurophysin, encompassing sequences homologous to mammalian msel-neurophysin and copeptin, has been passed through a trypsin-sepharose column in order to compare its conformation with that of the two-domain intermediate precursor isolated from guinea pig. whereas the polypeptide possesses 8 arginine residues, only two cleavages were observed located in a putative inter-domain sequence (at arg-94 and arg-114). because free vasotocin has been isolated from the frog, i ... | 1988 | 3258254 |
| relationship between estradiol-17 beta seasonal profile and annual vitellogenin content of liver, fat body, plasma, and ovary in the frog (rana esculenta). | the seasonal plasma estradiol-17 beta (e2-17 beta) profile and annual vitellogenin content of liver, fat body, plasma, and ovary were investigated in rana esculenta. concomitant with the increase in e2-17 beta, vitellogenin peaked in liver, plasma, and ovary during autumn and winter, while it remained at a relatively high concentration in fat body during spring. in vitro experiments showed that e2-17 beta (10(-9) m) is ineffective in inducing vitellogenin production in fat body, but is effective ... | 2012 | 3258838 |
| ultrastructural study of the semicircular canal cells of the frog rana esculenta. | the ultrastructure of the nonsensory cells (dark cells, transitional cells, and undifferentiated cells) of the frog semicircular canal was studied by using transmission electron microscopy in an attempt to correlate the structure with the functions of these epithelial cells. all the nonsensory cells were linked by tight junctions and desmosomes; this suggested that there is little paracellular ionic transport from perilymph to endolymph. in the dark cell epithelium, the apical intercellular spac ... | 1988 | 3259115 |
| immunocytochemical localization of vitamin a in the retina and pineal organ of the frog, rana esculenta. | vitamin a immunoreactive sites were studied in the retina and pineal organ of the frog, rana esculenta, by the peroxidase antiperoxidase, avidin-biotinperoxidase and immunogold methods. in dark-adapted material, strong immunoreaction was found in the outer and inner segments of the photoreceptor cells of both retina and pineal organ, as well as in the pigment epithelium, retinal müller cells and pineal ependymal cells. in light-adapted retina, cones and green (blue-sensitive) rods were immunopos ... | 1988 | 3259219 |
| formation of desmosomes and other contact specializations in cultured skin of the frog (rana esculenta). | small trypsinized explants from ventral skin of frogs (rana esculenta) were maintained in culture for 4 days during which a newly formed epithelium differentiated along the cut edges of the dermis. during the first 6 h adjacent cells produced numerous interdigitating lamellipodia. after 2 days, epithelial polarity was restored by the formation of zonulae occludentes and the epithelial cells were joined by a few small newly formed desmosomes and by numerous interdigitations. bipartite junctional ... | 2008 | 3259907 |
| na transport stimulation by novobiocin: intracellular ion concentrations and membrane potential. | microelectrodes and electron microprobe analysis were employed to study the effect of novobiocin on membrane potential and intracellular electrolyte concentrations in the frog skin epithelium. in both species investigated (rana esculenta and rana temporaria), novobiocin (1 mm, outer bath) caused a stimulation of transepithelial na transport, a depolarization of apical membrane potential, a fall in the apical fractional resistance, and an increase in the intracellular na concentration. the rise i ... | 1988 | 3260372 |
| histochemical and biochemical study on the acetylcholinesterase and choline acetyltransferase in the brain and spinal cord of frog, rana esculenta. | the histochemical distribution of acetylcholinesterase (ache) activity in the brain and spinal cord of rana esculenta, has been studied. moreover the levels of choline acetyl-transferase (chat) and of ache, have been determined biochemically in different regions of the central nervous system. the results obtained from combining the histochemical and biochemical analyses allowed us to obtain more significant information on the localization of cholinergic neurons and the projection areas of the ch ... | 1988 | 3261311 |
| electrophysiological and morphological study of polyneuronal innervation in the cutaneous pectoris muscle of adult frog (rana esculenta). | the incidence of polyneuronal innervation in the cutaneous pectoris muscle of the adult frog, rana esculenta, was determined quantitatively using electrophysiological and morphological techniques. the mean percentages of multiple innervated endplates obtained with both techniques from a series of 19 muscles examined at all times of the year were in very good correlation: 30.7% (196/639 endplates) by electrophysiology and 30.5% (478/1569 endplates) by morphology. in nine muscles examined during t ... | 1988 | 3262718 |
| [elimination of the genome of one of the parents prior to premeiotic dna synthesis in a hybridogenic species of rana esculenta]. | a dna-cytometric study was made of spermatogenesis of the hybridogenic european green frog r. esculenta, whose somatic cells have the ridibunda + lessonae genome. the dna amount in the ridibunda genome is by 16% more than the lessonae one. the dna content of esculenta somatic cells is exactly intermediate between those of both the parental species. on the contrary, the sperms (1c) and the primary spermatocytes (4c) of r. esculenta have the dna content which corresponds to the size of the ridibun ... | 1988 | 3262947 |
| high energy phosphate utilization for work production and tension maintenance in frog muscle. | frog (rana esculenta, l.) gastrocnemii (161 pairs) or sartorii (8 pairs) were stimulated by intermittent tetani at 10 degrees c (20 hz, supramaximal intensity, n2 atmosphere) isometrically (im) or isotonically (it) for various durations (6-30 s) at different tensions (0.05-1.00 po = maximal im tension at resting length, lo). the energy expenditure (e) was measured from atp and phosphocreatine breakdown and the high energy phosphate equivalent of lactic acid production. both in im and it conditio ... | 1988 | 3263619 |
| skin cultured with or without an nacl gradient and aldosterone influence epidermal fibronectin localizations. | fibronectin (fn) localizations in the epidermal cells of the frog rana esculenta were detected in isolated ventral skin fragments 4 day-cultured with or without an nacl transepithelial gradient and aldosterone. without the gradient, few mitochondria-rich cells (mrcs) were fn-detected. stratum germinativum and spinosum cells also contained fibronectin. with the gradient, numerous mrcs were detected. below them, in the stratum germinativum, clear spaces were recognized. aldosterone with or without ... | 1988 | 3263893 |
| arylsulphatase activity in the oviduct of the frog rana esculenta. ii. progesterone-induced changes following ovariectomy and hypophysectomy. | the effects of progesterone treatment on arylsulphatase activity were studied histochemically and biochemically in the frog oviduct under different experimental conditions. in ovariectomized animals, the hormone induced a large increase in enzyme activity, while in hypophysectomized ones there was a large decrease in this activity. these results indicate that the facilitatory and inhibitory effects of progesterone on arylsulphatase activity are influenced by the presence in situ of the gonad. hy ... | 1988 | 3264827 |
| odorant response of isolated olfactory receptor cells is blocked by amiloride. | olfactory receptor cells were isolated from the nasal mucosa of rana esculenta and patch clamped. best results were obtained with free-floating cells showing ciliary movement. 1) on-cell mode: current records were obtained for up to 50 min. under control conditions they showed only occasional action potentials. the odorants cineole, amyl acetate and isobutyl methoxypyrazine were applied in saline by prolonged superfusion. at 500 nanomolar they elicited periodic bursts of current transients arisi ... | 1988 | 3265442 |
| [thyroid homeostasis in animals with iodine deficiency]. | the content of total iodine, its hormonal and nonhormonal fractions as well the level of protein-bound iodine in blood and basic tissue targets in representatives of 4 classes of animals: esox lucius l., rana esculenta, streptopelia decaocto priv., lepus europaeus pall. inhabiting the mountain regions with iodine deficiency in environment and in the lowlands of transcarpathia with higher iodine provision have been investigated. a considerable decrease of general and hormone iodine level in the a ... | 1988 | 3265636 |
| granulopoiesis in tadpoles of rana esculenta. survey of the organs involved. | the topography and nature of granulopoietic tissues appearing during the larval period of rana esculenta have been investigated using light and electron microscopy. the formation of eosinophils and heterophils occurred in the interstices of the pronephros and opisthonephros, in the mesenchymal sheath surrounding the pronephric duct, as well as in the mesentery and mesenchymal coat of the bile duct and hepatic ducts. developing basophils were very rare, being detectable only in the stroma of the ... | 1988 | 3267013 |
| variation in thin filament size in the skeletal muscle of the frog. | the sartorius muscle of rana esculenta was fixed and dehydrated by different methods and cross-sections of sarcomeres of different lengths were examined by electron microscopy. the area within the outlines of the thin filaments in negatives was measured using a high-resolution television system and a graphics tablet or by using a microdensitometer and computer processing the images with a density threshold above the background level. in all specimens the area of the thin filaments in the i-bands ... | 1988 | 3267014 |
| a gonadotropin-releasing hormone (gnrh) antagonist decreases androgen production and spermatogonial multiplication in frog (rana esculenta): indirect evidence for the existence of gnrh or gnrh-like material receptors in the hypophysis and testis. | the effects of a gnrh antagonist (gnrha) on gnrh agonist (gnrh*)-induced androgen production and spermatogonial multiplication were studied in the frog, rana esculenta, in vivo and in vitro. intact and hypophysectomized (pdx) animals were kept at 22 +/- 2 c and treated with gnrh (45 ng/g bw) and gnrh* plus 1x and 10x concentrations of gnrha on alternate days for 2 weeks. androgen concentration in gnrh* plus gnrha-treated animals decreased in the testis by about 50% with the 10x dose whereas the ... | 1988 | 3275542 |
| immunocytochemical evidence for alpha-melanocyte-stimulating hormone in the hypothalamus of the frog rana esculenta. | the distribution of immunoreactive alpha-melanocyte-stimulating hormone (alpha-msh) within the brain of the frog, rana esculenta, has been studied on adjacent serial sections using an indirect immunofluorescence technique. immunoreactive cell bodies are found in the anterior part of the preoptic nucleus and in some ventral subependymal cerebrospinal fluid-contacting elements, and in the nucleus infundibularis ventralis. numerous alpha-msh-like immunoreactive fibers are present in the preoptic ar ... | 1987 | 3300993 |
| effect of sulmazole and pimobendan on contractility of skinned fibres from frog skeletal muscle. | the influence of two benzimidazole derivatives, 2-[(2-methoxy-4-methylsulfinyl)phenyl]-1h-imidazo [4,5-b] pyridine (sulmazole, ar-l 115 bs) and 4,5-dihydro-6-[2-(4-methoxyphenyl)-1h-benzimidazol-5-yl]-5-methyl- 3(2h)- pyridazinone (pimobendan, ud-cg 115 bs) on the ca2+-dependent isometric tension of skinned frog skeletal muscle fibres (tibialis anterior of rana esculenta) was investigated. both drugs sensitized the myofibrils of skeletal muscle for ca2+: at a drug concentration of 2 x 10(-4) mol ... | 1987 | 3435586 |
| the effect of an intraperitoneal injection of capsaicin on the thermopreferendum in the frog (rana esculenta). | in 7 frogs (rana esculenta) weighing 70 to 180 g, thermopreferendum (thp), measured by recording cutaneous temperature (ts) in the animal placed in the warm end of an aqueous temperature gradient (0 degree c-40 degrees c), equalled 25 +/- 2 degrees c. after an intraperitoneal (ip) injection of 20 mg/kg of capsaicin, thp was significantly decreased and equalled 3 +/- 1 degree c. the frogs then remained in the cold end of the gradient for 60 minutes. when the time of observation was extended to 3 ... | 1986 | 3485298 |
| phosphorylated proteins from anuran intestinal microvilli membranes--i. relations with alkaline phosphatase. | the degree of phosphorylation of intestinal microvilli membrane proteins in an adult amphibian, rana esculenta, was investigated under various experimental conditions. the microvilli protein phosphorylation rate rapidly increases during the first 4 min of incubation in a medium containing [gamma-32p]atp. this increase is slower afterwards. cyclic nucleotides (cyclic amp, cyclic gmp) and sorbitol do not modify the microvilli protein phosphorylation rate. on the contrary, this phosphorylation rate ... | 1986 | 3485510 |
| simultaneous labelling of two different central nervous system pathways with horseradish peroxidase and cobalt in gnathonemus petersii and rana esculenta. | a new and simple simultaneous labelling procedure is described that gives the possibility of studying interneuronal connections and territorial overlap of different pathways. this method uses horseradish peroxidase (hrp) labelling in combination with the cobalt-filling technique. the blue colour of the hrp reaction end-product formed from 0-tolidine (neuroscience, 4 (1979) 1805-1852) and the dark brown of cobalt-filled neurons and their processes allow easy distinction of the two different label ... | 1986 | 3485778 |
| on the metabolic basis of pseudopotentiation and superposition in the frog myocardium. | potentiation phenomena, tetanization and staircase of isolated surviving ventricle strips excised from hearts of 16 frogs (rana esculenta) were studied under quasiisometric conditions. pseudopotentiation of all kind, biphasic staircases and superposition of contractions characterizing the hypodynamic state following excision disappear in-vitro not only during normodynamic conditions but also in hypodynamia following in-vitro normodynamia. | 2012 | 3485971 |
| production of endolymph in the semicircular canal of the frog rana esculenta. | the mechanisms of secretion of endolymph were studied in vitro in the isolated inner ear of the frog. prior to in vitro experiments, the composition of perilymph was evaluated in vivo and compared to that of plasma. composition of perilymph resembled that of an extracellular fluid, although na and cl concentrations were higher and k concentration was lower in perilymph than in plasma water. no difference in ca and mg concentrations was observed between these two fluids. osmolality averaged 227 m ... | 2012 | 3486270 |
| effects of hypophysectomy and hormonal substances on the carbohydrate components of the oviduct of the rana esculenta complex. | 1986 | 3486719 | |
| preparation and characterization of two major isotypes of parvalbumins from skeletal muscle of bullfrog (rana catesbeiana). | two major isotypes of parvalbumins (pa1 and pa2) have been isolated from the skeletal muscle of bullfrog, rana catesbeiana. the mr values were estimated to be 10,100 (pa1) and 11,800 (pa2) by sds/polyacrylamide gel electrophoresis, and the isoelectric points were determined to be 4.78 (pa1) and 4.97 (pa2) by polyacrylamide gel isoelectric focusing. the amino acid compositions and isoelectric points indicate that pa1 corresponds to rana esculenta pi 4.50 and rana temporaria pi 4.75 parvalbumins a ... | 1986 | 3486865 |
| plasma and testicular estradiol and plasma androgen profile in the male frog rana esculenta during the annual cycle. | seasonal plasma and testicular estradiol levels were measured in the male frogs, rana esculenta, by radioimmunoassay. in plasma samples a simultaneous measurement of androgens was carried out in order to investigate a possible relationship between androgens and estradiol-17 beta. concomitantly with the estradiol-17 beta peak in plasma and testes during the april-may period, plasma androgens sharply decreased. | 1986 | 3492408 |
| regulation of androgen production by frog (rana esculenta) testis: an in vitro study on the effects exerted by estradiol, 5 alpha-dihydrotestosterone, testosterone, melatonin, and serotonin. | the possible role of estradiol-17 beta (e2), testosterone (t), 5 alpha-dihydrotestosterone (dht), melatonin, and serotonin on the regulation of androgen (a) production by the frog, rana esculenta, testes was studied in vitro. e2 (10(-6) m) inhibited a production whether alone or in combination with olh (20 micrograms) after 6 hr incubation. after 24 hr incubation. a production was reduced by e2 concentration of around 10(-6) and 10(-9) m. melatonin and serotonin did not induce any change whichev ... | 1986 | 3492409 |
| a comparative study on glyoxalase ii from vertebrata. | s-2-hydroxyacylglutathione hydrolase (glyoxalase ii) from the liver of animals belonging to the various vertebrate classes (oryctolagus cuniculus, gallus gallus, python molurus, rana esculenta, esox lucius) have been purified from 100,000 g supernatants of liver homogenates, using acetone fractionation and affinity chromatography. subsequent comparative studies were concerned with some molecular and kinetic properties. isoelectric focusing gave evidence for a single form of liver glyoxalase ii i ... | 1987 | 3495432 |
| mechanical work, oxygen consumption, and efficiency in isolated frog and rat muscle. | the total work done during shortening, in repeated stretch-shortening cycles and the subsequent recovery oxygen consumption were measured in isolated frog (rana esculenta) sartorius at 12 degrees c and rat (wistar strain) extensor digitorum longus (edl) and soleus at 20 degrees c. two procedures were followed. in the first, the muscles were lengthened in the relaxed state and stimulated isometrically just before and during the first part of shortening. the peak efficiency (positive work done div ... | 1987 | 3496797 |
| arterial supply of the choriocapillaris of anuran amphibians (rana temporaria, rana esculenta). scanning electron-microscopic (sem) study of microcorrosion casts. | the pattern of the vascular supply to the choroid of the frog eye was studied in toto with the use of the injection-replication-sem technique. the choroid of anuran amphibians is composed mainly of the choriocapillaris. in both species studied (rana temporaria, rana esculenta), an independent arterial supply to the choriocapillaris supplemented that from the ciliary arteries. this additional vascular route arises from the optic artery, a separate branch of the arteria infundibularis superficiali ... | 1987 | 3497721 |
| localization of steroid-concentrating cells in the central nervous system of the frog rana esculenta. | steroid-concentrating cells were localized using steroid hormone autoradiography in the brain of rana esculenta after systemic administration of tritiated estradiol and testosterone. highest numbers of labeled cells were found in the anterior preoptic area, in the ventral infundibular nucleus, and in the pituitary. other sites of tritiated sex steroid uptake were in the striatum, septum, amygdala, thalamus, tectum, torus semicircularis, and dorsal tegmental area of the medulla. no differences we ... | 1987 | 3497838 |
| seasonal plasma and intraovarian sex steroid profiles, and influence of temperature on gonadotropin stimulation of in vitro estradiol-17 beta and progesterone production, in rana esculenta (amphibia: anura). | seasonal plasma and intraovarian estradiol-17 beta (e) and progesterone (p) fluctuations were studied by specific radioimmunoassay in the frog, rana esculenta. moreover, incubations of ovine-luteinizing hormone (olh)-stimulated ovarian pieces at two different temperatures (15 and 24 degrees) have been carried out in order to evaluate the dependence of e and p output on this exogenous factor. estradiol showed similar changes in plasma and ovaries, while p profile was better evidenced in the gonad ... | 1987 | 3497839 |
| [action of diazepam on active sodium transport and permeability of skin isolated from rana esculenta]. | 1987 | 3498504 | |
| an attempt to record neuronal activity in the paraventricular organ of rana esculenta by means of a direct access to the infundibular recess. | in submammalian vertebrates, the paraventricular organ (pvo) of the third ventricle is a complex circumventricular structure composed of cerebrospinal fluid-contacting neurons and corresponding deeper formations of nerve cells. a new in-vivo technique enables us to approach the paraventricular organ of the frog, rana esculenta, via the lobus infundibularis. in this preparation, blood flow in the capillary loops beneath the pvo and the flow of the cerebrospinal fluid in the infundibular recess ca ... | 1987 | 3498536 |
| prolactin receptors in the male rana esculenta. | the binding of 125i-labeled ovine prolactin (oprl) to membrane preparations of several tissues from the male green frog, rana esculenta, collected during the year is reported. prl binding to kidney fractions was generally high (range 5-45%). a maximum was observed in the month of october, whereas the lowest value was found during the summer season. the binding to skin fractions was equally high (range 5-25%) and the annual profile parallels that of renal fractions. in the liver, a lower specific ... | 1987 | 3499360 |
| a horseradish peroxidase study of the olfactory system of the frog, rana esculenta. | the olfactory system of the frog rana esculenta was studied by using horseradish peroxidase (hrp) tracing of axonal pathways. injections of hrp were made in the main olfactory bulb (mob), accessory olfactory bulb (aob), anterior olfactory nucleus (aon), the amygdala (amy), and in a zone of the leteral wall of the telencephalic hemisphere immediately posterior to the aob. projections from these sites are described and are generally similar to those obtained by degeneration methods. however, hrp r ... | 1987 | 3499452 |
| [differences in the cyto- and angioarchitectonics of the ventral horns of the spinal cord in higher and lower vertebrates]. | when comparing structures of the ventral horns of the spinal cord in amphibia (rana esculenta) and carnivora (cat, dog), it has been stated that in the latter, together with increasing number of neurons their blood supply is improving. this is demonstrated as a growing density of the capillary network in the cerebral substance and increasing number of capillaries within 25 mcm around the neuronal bodies. glial surrounding of the neurons changes considerably. both in the amphibia and carnivora as ... | 1987 | 3501280 |
| one-step processing of the amphibian vasotocin precursor: structure of a frog (rana esculenta) "big" neurophysin. | vasotocin-associated neurophysin (msel-neurophysin) from the frog rana esculenta has been isolated and sequenced through tryptic and staphylococcal proteinase peptides and cyanogen bromide fragments. this protein appears homologous to the mammalian vasopressin-associated neurophysin with a c-terminal glycopeptide extension homologous to the mammalian copeptin. in contrast to the two-step processing of mammalian vasopressin/msel-neurophysin/copeptin precursor, a single cleavage is therefore invol ... | 1987 | 3501288 |
| the superficial vascular hyaloid system in the eye of the frogs, rana temporaria and rana esculenta. scanning electron-microscopic study of vascular corrosion casts. | the angioarchitecture of the superficial vascular hyaloid system (membrana vasculosa retinae) of the frog eye was studied by means of scanning electron microscopy of vascular corrosion casts. the terminal vessels form a single-layered sheath intimately adjacent to the vitreal side of the avascular retina. the hyaloid system is subdivided by the ventral venous trunk into three central areas: the dorsal, the temporo-ventral, and the naso-ventral area. toward the ora serrata, the hyaloid system is ... | 1987 | 3501334 |
| fused cells of frog proximal tubule: i. basic membrane properties. | proximal tubular cells of the frog (rana esculenta) kidney were fused within an isolated tubule portion to giant cells according to the polyethylene-glycol fusion method. cell membrane potentials (vm) were measured while cells were superfused with various experimental solutions. rapid concentration step-changes of different ions allowed to calculate the respective transference numbers (tion). in some experiments the specific cell membrane resistances (rm) were evaluated by measuring vm induced b ... | 1987 | 3501476 |
| three types of photoreceptors in the pineal and frontal organs of frogs: ultrastructure and opsin immunoreactivity. | the pineal complex in frogs (rana esculenta, r. temporaria, r. tigrina, r. arvalis) was studied by conventional electron microscopy and postembedding rhodopsin immunoelectron microscopy. three types of photoreceptor cells were found in both the pineal and frontal organs. in the pineal organ, most of the photoreceptors exhibited rhodopsin-immunoreactive outer segments and large inner segments with a large ellipsoid of densely packed mitochondria ("rod-like" photoreceptors). a small number of phot ... | 1986 | 3551870 |
| comparative studies on the astrocytic reaction in the lesioned central nervous system of different vertebrates. | the morphology of the optic nerve of fish, amphibians, reptiles, birds and mammals, with special reference to the membrane architecture of the astrocytes, is described by means of ultrathin sections and freeze-fracture replicas. the reaction patterns of the astrocytes in response lesions of the optic nerve are discussed with respect to the regenerative capacity of the central nervous system (cns). astrocytic membranes in the optic nerve of the goldfish and rana esculenta do not reveal orthogonal ... | 1987 | 3624861 |
| effect of phlorizin on the changes of membrane potential, water, na and k transport induced by cevadine in frog muscle. | the effect of phlorizin on the parameters of cevadine induced membrane potential oscillation and the development of the potential changes were investigated in frog (rana esculenta) sartorius muscles. the action of phlorizin on na transport, water and cation contents of cevadine-treated muscles were also studied. on the effect of phlorizin applied at a concentration of 1 mmol/1 the frequency of the membrane potential oscillation evoked by cevadine decreased by about half, parallel with an about f ... | 1985 | 3873168 |
| the effect of phenylalanine on intracellular ph and sodium activity in proximal convoluted tubule cells of the frog kidney. | the present study was performed to test the influence of sodium coupled transport of neutral substrates on intracellular ph and sodium activity in proximal tubules of the amphibian kidney. to this end, kidneys of rana esculenta have been isolated and perfused both through the portal vein (peritubular capillaries) and the aorta (luminal perfusate). the potential difference across the peritubular membrane of proximal tubule cells has been reduced with conventional (pdpt) as well as with sodium (pd ... | 1985 | 3874392 |
| preliminary researches on the characterization of the glycoconjugates in the oviduct of rana esculenta complex during its reproductive cycle. | biochemical investigations were carried out on the oviduct of rana esculenta. it was demonstrated that in the oviduct of rana esculenta there is a heteropolysaccharide formed by sulphated acid glycoconjugates and neutral glycoproteins. the presence and the functional role of glucidic components are discussed and compared to previous histochemical data. | 1985 | 3874566 |
| intermitochondrial junctions in the heart of the frog, rana esculenta. a thin-section and freeze-fracture study. | in muscle fibers of the frog heart, junctions between outer membranes of adjacent mitochondrial profiles are occasionally found. in thin sections of embedded tissue and of mitochondrial pellets, the intermitochondrial junctional space is 5.4 +/- 0.15 nm; the external leaflets of the membranes are joined by periodic structures separated from each other by 16.3 +/- 0.29 nm. there are 65.3 +/- 2 periodic structures per micron of membrane measured on a section perpendicular to the junction. after cr ... | 1985 | 3875412 |
| intracellular ph in diluting segment of frog kidney. | chronic exposure to high potassium (k+ adaptation) stimulates h+ net secretion in the diluting segment of the frog kidney. in order to investigate the cellular mechanism of the h+ secretory process intracellular ph (phi) measurements were performed in cells of the diluting segment of the isolated doubly-perfused kidney of k+ adapted rana esculenta. phi changes were monitored by ph-sensitive microelectrodes while the tubule lumen was rapidly perfused with various solutions. with control solutions ... | 1985 | 3875833 |
| influence of stimulation of the visual system on the activity of vestibular nuclear neurons in the frog. | in the frog (rana esculenta l.) we have tested the possible existence of visual inputs in the vestibular nuclei by recording the activity of second-order vestibular neurons receiving primarily horizontal canal inputs, while the visual system was stimulated by either light pulses or optokinetic stimulation; moreover, combined visuovestibular stimulation (horizontal rotatory stimulation in light) was performed and the response compared to the one obtained during vestibular stimulation alone (horiz ... | 1985 | 3876862 |
| active cell movements and embryonic cholinesterase in the postmetamorphic completion of the adrenal morphogenesis in frogs. | the adrenal gland in rana esculenta complex, as in other advanced anurans, is not yet in its definitive position at the end of the metamorphosis and reaches it subsequently, before sexual maturity. the displacement takes place by various means, among which active cellular movements prevail. these are demonstrated by the presence of acetylcholinesterase (ache) in noninnervated cells (embryonic ache). the disintegration of the connective tissues which delimit the cords of the adrenal gland, the pa ... | 1985 | 3878306 |
| cytochemical variations in purkinje neuron nuclei of cerebellar areas with different afferent systems in rana esculenta. comparison between activity and hibernation. | the distribution pattern of the feulgen-dna values (nuclear cytochemical heterogeneity) which provides information on the functional state of purkinje neurons was investigated in the lobus vestibularis and in the corpus cerebelli in active and hibernating frogs. in the corpus cerebelli, hibernation does not change greatly the nuclear heterogeneity of purkinje neurons, while in the lobus vestibularis this neuron population becomes more homogeneous and shows more condensed chromatin. these data su ... | 1985 | 3879258 |
| catecholaminergic and serotoninergic brain structures in european green frogs: an autoradiographical study. | aminergic brain structures have been investigated by means of light microscopical autoradiography after injection of the tritiated catecholamines noradrenaline and dopamine and the indoleamine (or tryptamine) serotonin into the brain cavity of frogs of the rana esculenta complex. these amines are fairly specifically taken up by catecholaminergic and serotoninergic neurons, respectively, which are located in structures like the catecholaminergic preoptic recess organ; the mixed catecholaminergic- ... | 1985 | 3879449 |
| ultrastructure of venom glands in the frog (rana esculenta). | electron microscopic study of skin venom glands in the frog, rana esculenta, revealed the syncytial structure of the inner (secretory) wall which presents two distinct zones: a basal (juxtamuscular) one, which contains nuclei and major cytoplasmic organelles, and an apical one where large electron-dense granules form and accumulate. granules are seen to arise inside clusters of tightly packed smooth endoplasmic reticulum (ser) elements, which suggests that the ser system is mainly involved in sy ... | 1985 | 3879578 |
| binocularly driven neurons in the rostral part of the frog optic tectum. | receptive field (rf) properties of binocular neurons lying in the rostral part of the optic tectum of the frog (rana esculenta) were studied electrophysiologically using conventional visual stimuli. they were classified into five groups: group 1 neurons have indefinite rf; group 2 neurons are total-field (t6) neurons; group 3 neurons have rfs covering a quadrant of the frontal visual field; group 4 neurons resemble t1(1) and t1(3) subclasses described earlier; and finally group 5 neurons look li ... | 1985 | 3879762 |
| effect of temperature and darkness on testosterone concentration in the testes of intact frogs (rana esculenta) treated with gonadotrophin-releasing hormone analog (hoe 766). | testicular testosterone was determined by radioimmunoassay in the frog (rana esculenta) kept in total darkness, at a high or a low temperature (24 or 4 degrees c), and treated with a gonadotrophin-releasing hormone analog (gnrha, hoe 766). prolonged exposure to dark conditions seemed to inhibit hypotalamic functions. moreover, it is shown that high temperature interacts positively with gnrha treatment on testicular testosterone concentration. | 1985 | 3921425 |
| morphology of the cells of origin of descending pathways to the spinal cord in rana esculenta. a tracing study using cobaltic-lysine complex. | the localization and morphological characteristics of neurons projecting to the spinal cord were studied with cobalt-filling technique. cobaltic-lysine complex was iontophorized into descending pathways in the lumbar and cervical intumescence of the spinal cord and in some parts of the rhombencephalon. well-filled cells located mainly in the rhombencephalon and telencephalon could be characterised as fusiform, triangular, multipolar and irregular neurons. piriform and pyramidal cells predominate ... | 1985 | 3934259 |
| a cytological study of the pars distalis of pituitary gland of normal, gonadectomized, and gonadectomized steroid hormone-treated green frog, rana esculenta l. | 1970 | 4097867 | |
| phylogenesis of mast cells. i. mast cells of the frog rana esculenta. | 1970 | 4101012 | |
| [fluorescence of the skin of amphibians (bombina variegata and rana esculenta)]. | 1970 | 4112168 | |
| hypothalamic control of the hypophyseal gonadotropic function in the adult male green frog, rana esculenta l. | 1972 | 4114822 | |
| sex differences in number of gomori-positive cells in the telencephalon of rana esculenta. | 1972 | 4124323 | |
| synthesis and intracellular transport of proteins in the exocrine pancreas of the frog (rana esculenta). i. an ultrastructural and autoradiographic study. | 1974 | 4140766 | |
| transformation of testosterone into 17beta-hydroxy-5beta-androstan-3-one by rana esculenta skeletal muscle. | 1974 | 4152608 | |
| [contribution to the study of stilling cells in rana esculenta l]. | 2014 | 4185986 | |
| an investigation by electron microscopy of the nucleoside phosphatase activity of amphibian and mammalian erythrocytes. | amphibian and mammalian blood was washed in isotonic saline, fixed in glutaraldehyde, and then stained in the atpase medium of wachstein and meisel. the blood cells were subsequently postfixed in osmium tetroxide, embedded in epoxy resins, and studied by electron microscopy. the plasma membranes of amphibian erythrocytes, from the newt triturus cristatus and the frog rana esculenta, were stained after incubation in media containing atp or adp as substrates, but were unstained after incubation in ... | 1965 | 4221862 |
| [comparative electrophysiologic study of the motor and sensory myelinized nerve fibers in rana esculenta and xenopus laevis]. | 1967 | 4234703 | |
| [action of metopirone on the cytology of the distal lobe of the pituitary of the green frog, rana esculenta (l)]. | 2014 | 4236614 | |
| [conditions determining the p anomaly in rana esculenta]. | 1969 | 4238622 | |
| [role of the pituitary gland in the phenomena of compensatory hypertrophy of the interrenal gland in the green frog, rana esculenta l]. | 1970 | 4248045 | |
| [effects of fasting on epithelial cells of the renal glomerulus in rana esculenta]. | 1970 | 4251917 | |
| [electrophysiological study of the various sorts of fibers and their numerical importance in the ampullar nerve of a semicircular canal in the frog (rana esculenta)]. | 1974 | 4279753 | |
| [the hormonal regulation of alkaline and acid phenylphosphatases, of acid proteinase and of alanyl-glycine dipeptidase of the oviduct of rana esculenta. i. action of 17-beta-estradiol]. | 1966 | 4287776 | |
| [study of the activity of some hydrolases (alkaline and acid phosphatases, acid proteinase and alanylglycine dipeptidase) of the oviduct of rana esculenta during the reproductive cycle]. | 2016 | 4300501 | |
| [effects of bilateral adrenalectomy on the cytology of the distal lobe of the pituitary of the green frog (rana esculenta); attempt to identify the cells responsible for the secretion of corticotropic hormone]. | 1967 | 4302165 | |
| [cytologic modifications of the pituitary and interrenal gland of the green frog, rana esculenta l., after unilaternal adrenalectomy]. | 1969 | 4309272 | |
| [natriuretic and hydrosmotic responses to theophylline in rana esculenta after adaptation to low temperature]. | 2015 | 4309557 | |
| [effects of unilateral adrenalectomy on pituitary and adrenal gland cytology in rana esculenta l]. | 2015 | 4309564 | |
| [lactate production from fumarate by rana esculenta liver mitochondria]. | 2015 | 4310816 | |
| [study of the interrenal tissue of the green frog rana esculenta l., after ectopic graft of the pituitary gland into the eye, adrenal gland and testis]. | 1970 | 4324907 | |
| [seasonal morphological and biochemical changes in the liver of rana esculenta]. | 1971 | 4325967 | |
| some properties of crystalline inclusion bodies in oocytes of rana temporaria and rana esculenta. | 1972 | 4335160 | |
| ultrastructural studies of oogenesis in some european amphibians. i. rana esculenta and rana temporaria. | 1972 | 4336790 | |
| [evolution of corticotropic formation, in the green frog, rana esculenta l., after ectopic transplantation of the distal lobe of the hypophysis]. | 2016 | 4337252 | |
| [control of hypophyseal corticotropic activity by the hypothalamus, in green frogs, rana esculenta l]. | 1971 | 4339994 |