plasma thyroxine and triiodothyronine levels in spontaneously metamorphosing rana catesbeiana tadpoles and in adult anuran amphibia.we have developed sensitive and reliable radioimmunoassays for t4 and t3 in amphibian plasma and have used these procedures to measure plasma t4 and t3 levels in spontaneously developing rana catesbeiana tadpoles at various stages of metamorphosis. during premetamorphosis circulating levels of both t4 and t3 were below the limits of detection of the ria procedures (t4 less than 50 ng/100 ml, t3 less than 5 ng/100 ml). a gradual rise in plasma t3 and t4 became apparent during prometamorphosis, an ...1978105869
thyroid hormone-aldosterone interaction on na+ transport in toad bladder.repeated administration of thyroxine (t4) in vivo (2 microgram/100 g body wt for 6 days) lowered by 2.3 times (p less than 0.025, df = 18) the basal rate of na+ transport measured by the short-circuit current (scc) in vitro in the urinary bladder of the toad (bufo marinus). this difference was not accounted for by a change in the plasma aldosterone concentration. moreover the response of the scc to aldosterone in vitro was markedly inhibited in bladders from t4-treated animals (p less than 0.001 ...1979106733
salmonella in wildlife from trinidad and grenada, w.i.forty-four of 219 animals from trinidad and grenada, w.i., yielded 20 serotypes of salmonella, 16 of which are known to have been associated with human infection in the united states in recent years. toads (bufo marinus) provided the greatest number of isolates. other carriers were mammals, vultures, lizards, a tree-frog and a cave cockroach.1979113561
differences in pulmonary microvascular anatomy between bufo marinus and xenopus laevis.1. histological and corrosion-casting techniques have been used to provide a comparison of lung structure between a terrestrial load (bufo marinus) and an aquatic one (xenopus laevis). the pulmonary microvascular anatomy is distinctly different in these two species and both differ from classical descriptions of other anuran lungs. 2. in x. laevis large peribronchial vessels form a number of direct connections between the pulmonary artery and vein at the base of the lung. as a result of their loc ...1977402217
chromomycosis in the toad (bufo marinus) and a comparison of the etiologic agent with fungi causing human chromomycosis.of 75 toads (bufo marinus) 2 were found infected by black molds. the internal organs of these animals had granulomatous lesions containing brown fungi identical to those found in human chromomycosis. cultures gave rise to slow-growing black molds but all attempts to induce sporulation failed. the fungi did not grow at 36 degrees c or above and failed to hydrolyse gelatin or casein. immunodiffusion and immunoelectrophoresis revealed that both isolates were identical and shared common antigens wit ...1975804722
studies on the interaction of organic phosphates with haemoglobin in an amphibian (bufo marinus), a reptile (trachydosaurus rugosus) and man.the primary organic phosphate modifiers of haemoglobin function are dpg (2,3-diphosphoglycerate) in the toad bufo marinus and atp in the lizard trachydosaurus rugosus. myo-ip6 (myo-inositol hexaphosphate) and myo-ip5 (myo-inositol pentaphosphate) are more effective than atp or dpg in reducing the oxygen affinities of the haemoglobins of b. marinus, t. rugosus and man, while atp and dpg are about equally effective. competition experiments indicate that atp, dpg and myo-ip6 bind to the same site o ...1975811198
a primary immune response of bufo marinus spleen cells in vitro.single-cell suspensions of bufo marinus spleen have been induced to produce a primary immune response to a soluble purified protein. using polymerized flagellin from salmonella adelaide as antigen and culture conditions commonly available in most laboratories but new for amphibian cells, it has been found that in vitro at 37 degree c, toad spleen cells produce an antibody-forming cell response optimal at day 6. the response depends on the number of cultured cells and dose of antigen, and paralle ...1975829903
the beta subunit modulates potassium activation of the na-k pump.we recently cloned the alpha 1 and the beta 1 and beta 3 subunits of the na,k-atpase of the toad bufo marinus. to investigate possible functional differences between beta 1 and beta 3, we studied the potassium activation of na-k pumps expressed in the oocyte of xenopus laevis. na-k pump activity was measured as k(+)-induced current in voltage-clamped oocytes. we could take advantage of the relative resistance to ouabain conferred by the bufo alpha subunit to study specifically the exogenously ex ...19921337667
primary sequence and functional expression of a novel ouabain-resistant na,k-atpase. the beta subunit modulates potassium activation of the na, order to understand the molecular mechanism of ouabain resistance in the toad bufo marinus, na,k-atpase alpha and beta subunits have been cloned and their functional properties tested in the xenopus laevis oocyte expression system. according to sequence comparison between species, alpha 1, beta 1, and beta 3 isoforms were identified in a clonal toad urinary bladder cell line (tbm 18-23). the sequence of the alpha 1 isoform is characterized by two positively charged amino acids (arg, lys) at t ...19921380956
neuron-specific enolase-like immunoreactivity in the vertebrate retina: selective labelling of müller cells in anura.neuron-specific enolase (nse) immunocytochemistry was carried out in retinae of goldfish, axolotl, clawed frog, cane toad, lizard, chick, guinea-pig, rabbit, rat, cat and human. with the exception of anura, strong immunoreactivity was seen in the large ganglion, amacrine cells and horizontal cells of the retina in all of the other species. photoreceptors were found to be labelled in the rat and human retina and only one cone type in rabbit. photoreceptor pedicles and ellipsoids were stained in t ...19921459864
effect of carbenoxolone sodium on steroid-induced sodium transport in the toad bladder: further studies.the licorice derivative, carbenoxolone sodium, is a potent inhibitor of the enzyme 11 beta-hydroxysteroid dehydrogenase. when this enzyme is suppressed or is absent, endogenous glucocorticoids induce mineralocorticoid-like sodium retention by the kidney. carbenoxolone sodium administered in vivo to an adrenalectomized rat has also recently been shown to enhance the mineralocorticoid response to submaximal concentrations of aldosterone, deoxycorticosterone (doc) and 11-dehydrocorticosterone (comp ...19921525050
haematopoietic malignancies in zoo animals.myelogenous leukaemia was found in a russell's viper, a honduran milk snake, a marine toad, a byrne's marsupial mouse and an african hedgehog. lymphocytic leukaemia was present in a broad banded copperhead and an indian lion. visceral lymphomatosis was observed in a snowy owl.19921556254
polymorphism in purified guanylate cyclase from vertebrate rod photoreceptors.guanylate cyclase from rod photoreceptors of amphibian (toad, bufo marinus, and frog, rana catesbeiana) and bovine retinas was solubilized and purified by a single chromatography step on a gtp-agarose column. silver staining of purified amphibian enzymes in sds/polyacrylamide gels disclosed a doublet band (110 and 115 kda), while the bovine enzyme appeared as a singlet band (110 kda). the identification of these guanylate cyclases was confirmed using three chromatography systems with the purifie ...19911675787
leptospires isolated from toads and frogs on the island of barbados.four pathogenic strains of leptospires were isolated from the kidneys of toads (bufo marinus) and seven from frogs (eleutherodactylus johnstonei). isolates from two toads and one frog belonged to serovar bim, the causative agent of most cases of severe leptospirosis on barbados. the other eight strains belonged to a new serovar within the australis serogroup. the name bajan is proposed for this new serovar of leptospira interrogans.19911741925
a method for the demonstration of nadph-diaphorase activity in anuran species using unfixed retinal wholemounts.the presence of nadph-diaphorase enzyme has been previously revealed in fixed mammalian retinal tissue (sagar, 1986). fixed retinae of bufo marinus and xenopus laevis failed to yield selective staining when reacted for nadph-diaphorase. satisfactory staining of retinal neurons was attained when the histochemical reaction was carried out in unfixed retinal wholemounts. the applied method included the following steps: 1) dissection of the fresh retina and the separation of the neural retina from a ...19911908262
a possible iridovirus in erythrocytes of bufo marinus in costa rica.icosahedral viral particles were found in the cytoplasm of erythrocytes and splenic reticular cells of a marine toad (bufo marinus) collected from costa rica. capsids had a maximum diameter of 312 nm and a spherical core with biphasic electron density. viruses in erythrocytes were associated with cytoplasmic assembly areas and vacuoles in cytoplasm. nuclei had finely granular material of decreased electron density located centrally, but contained no viral particles. a group of unenveloped viral ...19911920667
an epidemiological study of snake bite envenomation in papua new guinea.we report a study of 347 patients with snake bite envenomation in papua new guinea. the male: female ratio of the victims was 1.6:1 and their mean age was 24.5 years; 26% were children less than 15 years old. in all cases in which the bite site was known (334) the snake had bitten the extremities of the victim, with 71.3% of these bites being on the ankle or below. the patients came from three regions: urban papua, rural papua and (mostly rural) new guinea. snake bites occurred more frequently d ...19911994203
salmonellas from the cane toad, bufo marinus. 19902121128
determination of intracellular ph and pco2 after metabolic inhibition by fluoride and nitrilotriacetic acid.mean intracellular ph (phi) and pco2 (pico2) have been analysed based on ph and total co2 measurements in tissue homogenates. tissues were sampled from undisturbed worms (sipunculus nudus), squid (illex illecebrosus), trout (salmo gairdneri), toads (bufo marinus), and rats. homogenate metabolism was inhibited by the addition of potassium fluoride and nitrilotriacetic acid (nta). model calculations revealed that the influence of dilution, medium buffers, and contamination by extracellular fluids ...19902124717
detection of n-acetylated forms of beta-endorphin and nonacetylated alpha-msh in the intermediate pituitary of the toad, bufo marinus.steady-state analysis of the acid extracts of the intermediate pituitary of the toad, bufo marinus, revealed the presence of multiple forms of beta-endorphin and alpha-msh. approximately 98% of the immunoreactive beta-endorphin was n-acetylated. the major form of n-acetylated beta-endorphin, which represented 81.5% of the total beta-endorphin recovered from this tissue, had an apparent molecular weight of 1.2 kda and a net charge of +1 at ph 2.75. approximately 98% of the immunoreactive alpha-ms ...19902172945
a method for recording isometric tension development by isolated cardiac myocytes: transducer attachment with fibrin glue.the purpose of this study was to develop a method for attachment of single isolated cardiac myocytes to a transducer for recording isometric tension development. cardiac myocytes were isolated from the hearts of the toad, bufo marinus or ferrets by enzymatic digestion with collagenase. the method that we used provided a 60-80% yield of ca++-tolerant cells. a suspension of cells was placed into a superfusion chamber coated with bovine thrombin. two glass microtools - each attached to a micromanip ...19872437526
metabolic origins of 5-hydroxytryptamine in enteric neurons in a teleostean fish (platycephalus bassensis), a toad (bufo marinus) and the guinea-pig.1. 5-hydroxytryptamine (5-ht) content and synthesis in mucosa-free intestine of guinea-pig, the teleost platycephalus bassensis and the amphibian bufo marinus was studied by hplc with electrochemical detection or by tlc. 2. the 5-ht content of small intestine was: guinea-pig 0.58; bufo: 1.23; platycephalus: 26.88 nmol/g. 3. intestine from each species synthesized 5-ht from exogenous 5-htp. 4. platycephalus preparations synthesized labelled 5-ht from 14c-tryptophan, but no labelled 5-ht was detec ...19892468444
morphological characterization of substance p-like immunoreactive amacrine cells in the anuran retina.using substance p immunohistochemistry it was possible to demonstrate a class of morphologically homogeneous group of neurons in the inner nuclear layer (inl) of the retina of two anuran species: xenopus laevis and bufo marinus. the number of cells with substance p-like immunoreactivity (sp-li) was about 250 and 800 in juvenile and 600 and 2500 in adult xenopus and bufo, respectively, sp-li cells had a small soma with one primary dendrite having up to four slender branches, located in the vitrea ...19892475974
cross-reactivity of an antiserum to the alpha-subunit of the na+, k+-atpase of toad (bufo marinus) kidney with basal and apical membranes of transporting epithelia of the antibody to the 96 kd alpha-subunit of the na+, k+-atpase from bufo marinus has been used in immunostaining rat kidney and salivary glands. intense staining was observed on basolateral membranes of distal tubules of the kidney and striated ducts of the three major salivary glands. less intense staining was seen on the basolateral membranes of parotid acinar cells, but no staining was seen on the acinar cells of submandibular or sublingual glands. these sites of staining have been shown, by ot ...19892478290
why are blue visual pigments blue? a resonance raman microprobe study.a resonance raman microscope has been developed to study the structure of the retinal prosthetic group in the visual pigments of individual photoreceptor cells. raman vibrational spectra are obtained by focusing the probe laser on intact photoreceptors frozen on a 77 k cold stage. to elucidate the mechanism of wavelength regulation in blue visual pigments, we have used this apparatus to study the structure of the chromophore in the 440-nm absorbing pigment found in "green rods" of the toad (bufo ...19892493645
functional similarities in the mechanical design of the aorta in lower vertebrates and mammals.the mechanical properties of the aorta from the toad bufo marinus, the lizard gekko gecko and the garter snake thamnophis radix were compared to those of the rat, by inflation of vessel segments in vitro. the arteries of the lower vertebrates, like those of mammals, were compliant, highly resilient, and non-linearly elastic. the elastic modulus of the artery wall was similar in the lower vertebrates and mammals, at their respective mean physiological pressures. we conclude that the aorta in each ...19892513219
dissociation of force from myofibrillar mgatpase and stiffness at short sarcomere lengths in rat and toad skeletal muscle.1. single fast-twitch fibres from the extensor digitorum longus muscle of the rat, rattus norvegicus, and single twitch fibres from the iliofibularis muscle of the cane toad, bufo marinus, were mechanically skinned and then used to measure maximally ca2+-activated [( ca2+] greater than 0.03 mmol l-1) isometric force production, myofibrillar mgatpase activity and fibre stiffness at different sarcomere lengths. mgatp hydrolysis was linked by an enzyme cascade to the oxidation of nadh (nicotinamide ...19892529371
cellular electrophysiologic effects of vertebrate digitalis-like substances.substances structurally and functionally similar to digitalis glycosides are produced by several vertebrate species. there also is evidence for a digitalis-like substance of human origin. standard microelectrode techniques were used to study the direct effects on the cellular electrophysiology of canine purkinje fibers of 1) bufalin, an unconjugated cardiotonic steroid molecule that is produced by the toad bufo marinus, and 2) an extract of human bile that showed digitalis-like immunoreactivity ...19882830326
detection of poisoning by plant-origin cardiac glycoside with the abbott tdx analyzer.cardiac glycoside poisoning caused by ingestion of plant material is common in tropical and sub-tropical areas. in evaluating the use of the abbott tdx digoxin ii assay to detect such cases of poisoning, we found it a rapid and convenient method for confirming the ingestion of glycosides from the plants nerium oleander, thevetia peruviana, and adonis microcarpa, and from the toad bufo marinus. here we report some clinical cases illustrating our experience with the use of this assay, and describe ...19892914377
ca2+ and mgatp2- dependence of shortening in skinned single smooth muscle cells.most studies of skinned smooth muscle have been performed in whole tissue preparations. in this study, we report the development of a chemically skinned single smooth muscle cell preparation from the toad, bufo marinus, stomach. isolated smooth muscle cells were skinned using saponin. the effect of various ionic environments (i.e., changing free ca2+ and mgatp2-) on skinned cell contractile response was assessed by measuring cell lengths from populations of cells using a computer-assisted length ...19872952016
specific binding sites for ovine prolactin in three amphibian cell lines.established cell lines (tb-6c and tb-m) obtained by continuous culture of epithelial cells from toad bufo marinus urinary bladder, which, in culture, maintained a high degree of functional differentiation, exhibited a significant number of high-affinity (ka = 1-2 x 10(10) m-1) binding sites detected both with radioiodinated (125i) ovine prolactin (oprl) and human growth hormone (hgh). binding capacity was higher in the case of tb-6c cells (7,573 +/- 581 sites/cell) than with the tb-m cells (1,16 ...19852981477
effects of bilirubin on transepithelial transport of sodium, water, and urea.urinary concentrating defects and renal salt wasting have been described in the hyperbilirubinemic gunn strain strain of rat. homozygous animals demonstrate significant reductions in renal medullary urea and sodium ion concentrations. these observations are consistent with possible bilirubin associated disorders in the transepithelial transport of water and solute. to test this hypothesis, measurements of active sodium transport and passive water and urea fluxes were made in hemibladders isolate ...19852984453
the ecological genetics of introduced populations of the giant toad, bufo marinus. iv. gene flow estimated from admixture in australian populations.allele frequency variation is described at nine polymorphic enzyme loci in 21 samples from populations of the introduced giant toad, bufo marinus, in the region of townsville in north queensland, australia. some of these populations appear to have been established through the introgression of other populations that previously had been isolated. comparisons of allele frequencies at three polymorphic loci between the introgressed populations and the original populations are used to obtain admixtur ...19863084402
light-dependent binding of g-protein to outer segment membranes of toad photoreceptors.light-dependent changes in the binding of g-protein were analyzed in outer segment disk membranes obtained from photoreceptors of the toad (bufo marinus) retina. isolated, intact retinas, incubated in oxygenated ringer's solution at 23 +/- 1 degree c, were subjected to various conditions of illumination and then incubated in darkness for specified periods. the retinas were then chilled (0-4 degrees c) and the receptor outer segments (ros) were isolated. binding of the alpha- and beta-subunits of ...19863097246
purification of prl receptors from toad kidney: comparisons with rabbit mammary prl receptors.the binding characteristics of the prolactin (prl) receptors present in toad (bufo marinus) kidneys were investigated and compared to those of prl receptors present in rabbit mammary glands. the molecular characteristics of the triton x-100 solubilized renal and mammary prl receptors were assessed by gel filtration and by migration analysis on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (sds-page) after affinity labeling of the binding sites with 125i-human growth hormone. similar ...19883126667
localization of immunoreactive synthetic atrial natriuretic factor (anf) in the heart of various animal species.the localization of two synthetic fragments of the c-terminal portion of atrial natriuretic factor: arg 101-tyr 126 which displays full biological activity and leu 94-arg 109 which is completely devoid of biological activity, has been investigated by immunohisto- and immunocytochemical methods in the heart of mammals (rat, mouse, guinea pig, hamster, rabbit, cat, dog, man) and nonmammalian vertebrates toad (bufo marinus), frog (rana catesbeiana), fish (cyprinus carpio, puntius schwanenfeldi, cic ...19853158698
species specificity of transferrin binding, endocytosis and iron internalization by cultured chick myogenic cells.the ability of unlabelled heterologous transferrin to interact with transferrin receptors on developing chick myogenic cells was investigated by measuring their capacity to inhibit the surface-binding and internalization of 125i- and 59fe-labelled ovotransferrin. transferrins from rat, rabbit, human, and a species of kangaroo (macropus fuliginosus) were unable to inhibit either surface-binding or internalization of labelled ovotransferrin even at concentrations ten times the molar concentration ...19883249019
the ecological genetics of introduced populations of the giant toad bufo marinus. ii. effective population size.the allele frequencies are described at ten polymorphic enzyme loci (of a total of 22 loci sampled) in 15 populations of the neotropical giant toad, bufo marinus, introduced to hawaii and australia in the 1930s. the history of establishment of the ten populations is described and used as a framework for the analysis of allele frequency variances. the variances are used to determine the effective sizes of the populations. the estimates obtained (390 and 346) are reasonably precise, homogeneous be ...19853922852
anticomplementary fraction from the poisonous secretion of the paratoid gland of the toad (bufo marinus paracnemis lutz).fractionation of the poisonous secretion of the toad bufo marinus paracnemis lutz, by dialysis and chromatography on qae-sephadex, led to the isolation of a fraction which was adsorbed to the ion exchanger. this fraction, when incubated with human serum, yielded an anticomplementary effect that was evaluated by measuring the kinetics of lytic activity on sensitized sheep red cells (classical pathway) and unsensitized rabbit cells (alternative pathway).19853924651
gastric emptying and intestinal transit in bufo marinus and the actions of e prostaglandins.gastric emptying and intestinal transit have been studied in the anuran bufo marinus using tc99-labelled chicken liver as the test meal. gastric emptying was measured as the proportion of the test meal remaining in the stomach after 3 or 6 h. intestinal transit was calculated by the geometric centre method at the same time intervals. there was a high degree of variability in these parameters between individual animals, in both control and treated groups. both sc29333 (searle), a synthetic e pros ...19853929758
cellular and humoral aspects of the primary immune response of the toad, bufo marinus. 19704190419
translation of rabbit haemoglobin mrna in oocytes of the queensland cane toad, bufo marinus. 19744219274
spontaneous occurrence and experimental transmission of the fungus, fonsecaea pedrosoi, in the marine toad, bufo marinus. 19734347757
some aspects of the inhibition of the action of antidiuretic hormone by lithium ions in the rat kidney and bladder of the toad bufo marinus.1. the effect of intravenous infusions of various ions on the antidiuretic action of antidiuretic hormone has been studied in rats.2. lithium (13 mmol/l.) reversibly inhibits the antidiuretic responses. similar concentrations of potassium, rubidium, strontium, magnesium, choline and calcium do not. lithium has a similar effect on the antidiuretic activity of oxytocin.3. the inhibition is not simply related to blood nor whole body lithium concentrations.4. lithium (2 mmol/l.) in contact with the ...19724358411
immunofluorescent detection and localization of thyroxine in blood of adult amphibians.indirect immunofluorescent staining was used to detect and localize thyroxine (t4) in blood smears from different species of adult amphibians, namely, rana pipiens, rana catesbeiana, bufo marinus, xenopus laevis, and notopthalmus viridescens. fluorescence, indicative of t4, was observed in both plasma and erythrocytes (rbc) from all individuals of the five species studied. it was weak and diffuse in the plasma and in the cytoplasm of the rbc but was intense in the nuclei (especially the nuclear ...19863542699
melanophore stimulating hormone: release inhibition by ring structures of neurohypophysial hormones.tocinamide and tocinoic acid, ring structures of oxytocin, are potent inhibitors of the release of melanophore stimulating hormone from the rat and hamster pituitary in vitro. tocinamide is effective at concentrations as low as 10-(14)m on the mammalian pituitary. these peptides do not affect release of the hormone on the frog (rana pipiens) pars intermedia, but they do inhibit release in the bullfrog (rana catesbeiana) and the toad (bufo marinus). the specificity of the peptides on inhibition o ...19724624585
purification and characterization of two classes of immunoglobulins from the marine toad, bufo marinus. 19724625312
tolerance to a protein antigen in a poikilotherm, the marine toad bufo marinus. 19714930986
prolactin, calcitonin, and blood calcium in the toads bufo boreas and bufo marinus. 19715001863
comparative effects of mammalian prolactin and growth hormone on growth in the toads bufo boreas and bufo marinus. 19695406003
leptospires in the marine toad (bufo marinus) on barbados.leptospires were isolated from the kidneys of four of 211 toads (bufo marinus) caught on barbados. two of the isolates were identified as leptospira interrogans serovar bim in the autumnalis serogroup (the most common cause of leptospiral illness on barbados), and two as possibly new serovars in the australis serogroup. sera from 198 of the toads were examined by the leptospire microscopic agglutination test. forty-two (21%) were positive at titers of greater than or equal to 1:100, and 54 (27%) ...19883373639
identification of two isoforms of the catalytic subunit of na,k-atpase in myocytes from adult rat heart.the present study demonstrates that two forms of the alpha catalytic subunit of the na,k-atpase are present in rat heart and originate from cardiomyocytes. they were resolved on sodium dodecyl sulfate-polyacrylamide gel electrophoresis after reduction and alkylation of the sulfhydryl groups. the two forms were identified on immunoblots using two specific antisera against either the alpha subunit from bufo marinus kidney and the alpha and beta subunits from lamb kidney. comparison of the two form ...19873036837
an inhibitor of oxytocin from the urinary bladder of the toad, bufo marinus. 19655886052
[influence of the ph of the solution of serum gonadotropin on spermatozoa release in the toad (bufo marinus l.)]. 19655893182
phylogenetic studies on the immune response. i. localization of antigens and immune response in the toad, bufo marinus. 19665913114
the morphological characterization and distribution of displaced ganglion cells in the anuran retina.the number, dendritic morphology, and retinal distribution of displaced ganglion cells were studied in two anuran species, xenopus laevis and bufo marinus. horseradish peroxidase or cobaltic lysine complex was applied to the cut end of the optic nerve, and the size, shape, and retinal position of retrogradely filled ganglion cells displaced into the inner nuclear layer were determined in retinal wholemount and sectioned material. approximately 1% of ganglion cells in xenopus and 0.1% in bufo wer ...19892518634
serosal and mucosal facilitated transport of urea in urinary bladder of of bufo bufo: evidence for an alleged water bufo bufo urinary bladder an urea facilitated transport has been localised on the luminal membrane. the transport fulfils the criteria for such a mechanism, i.e. is saturable and is inhibited by phloretin, a specific inhibitor for urea transport. similarly to that of bufo marinus and rana esculenta the luminal membrane of bufo bufo urinary bladder shows an adh stimulated facilitated transport. experiments wtih amphotericin b, serosal phloretin (with and without adh), have demonstrated the pre ...19836135534
retino-retinal projections in three anuran juvenile and adult xenopus laevis, in adult bufo marinus and rana esculenta frogs retino-retinal projections were traced by filling the central stump of one optic nerve, cut 2-3 mm from the eye, with horse-radish peroxidase (hrp) or cobaltic-lysine complex (clc). the presence of retino-retinal projections was confirmed in all 3 species both in the juvenile and the adult. up to 12 ganglion cells per retina were found to be filled retrogradely with hrp together with optic axons filled anterogra ...19892510094
stimulation of adenosine 3',5'-monophosphate formation in mononuclear leukocytes by toad venoms.the content of adenosine 3',5'-monophosphate in human mononuclear leukocytes was enhanced 3-5-times by venoms obtained from african toad (bufo africanus), american toad (bufo americanus), colorado river toad (bufo arenarum) and marine toad (bufo marinus) at 25 micrograms/ml for 5 min of incubation at 37 degrees c. the maximum stimulation was observed after 1-5 min of incubation. the half-maximal stimulation was observed at 0.1 micrograms/ml venom obtained from colorado river toad (bufo arenarum) ...19826184077
hormone effects on transport in cultured epithelia with high electrical resistance.three continuous lines of amphibian epithelial cells form epithelia with a high transepithelial resistance (greater than 4,000 omega . cm2) in culture. the cell lines are tb-m and tb-6c, derived from the urinary bladder of bufo marinus, and a6, derived from the kidney of xenopus laevis. short-circuit current is equivalent to net mucosa-to-serosa sodium transport in two cell lines and slightly exceeds sodium transport in epithelia formed by tb-6c cells. none of the cell lines has an adenylate cyc ...19816259946
interphotoreceptor retinoid-binding protein: role in delivery of retinol to the pigment epithelium.the ability of interphotoreceptor retinoid-binding protein (irbp) to facilitate the incorporation of retinol into retinyl esters by the retinal pigment epithelium (rpe) was examined in toad (bufo marinus) eyecup preparations devoid of neural retina (rpe-eyecup). solutions containing purified bovine irbp and all-trans[3h]retinol were introduced into the vitreal cavity of the rpe-eyecup. after incubation at 22 degrees c, [3h]retinyl ester was extracted from the rpe cells and isolated by high perfo ...19892509230
direct effect of complement factor c5a on the contractile state of isolated smooth muscle cells.the complement-(c) derived factor c5a has long been recognized as a potent contractile agonist in smooth muscle (1,2); however, controversy remains as to whether the effects of this anaphylatoxin are direct or secondary to the release of histamine (3) and/or other mediators (4-8) from nonmuscle cells within the tissue. to resolve this controversy, we have assessed the contractile effects of purified human c5a and c5a des arg in a homogeneous preparation of enzymatically dispersed smooth muscle c ...19836300236
evidence for a role of calmodulin in the hydrosmotic action of vasopressin in toad bladder.1. the informational role of cytosolic ca2+ appears to be mediated by a ubiquitous protein--calmodulin--in most cell systems. 2. evidence has been accumulating that not only camp, but also ca2+, behaves as an intracellular messenger in the stimulation of water transport by vasopressin (hydrosmotic effect). 3. to examine whether calmodulin plays a role in the hydrosmotic effect of vasopressin, we used a specific antagonist of calmodulin--trifluoperazine--and looked at its effects on water transpo ...19826300378
rod light response augmented by active phosphodiesterase.light activates rod outer segment (ros) phosphodiesterase (pdease), as shown by previous biochemical and physiological studies. we have further investigated the role of pdease in this system by injecting trypsin-activated pdease, purified from bovine ros, into single ros of the isolated retina of the toad bufo marinus. injection of about 300 molecules of activated pdease in darkness is without immediate detectable effect, as measured by intracellular membrane-voltage recording. the effect of the ...19846320200
properties of dna rosettes and their relevance to chromosome structure.we have studied the spreading conditions that lead to the formation of rosettes in dna and chromatin preparations from the amphibians bufo marinus and bolitoglossa subpalmata and the bacterium shigella. both nuclear preparations and extensively deproteinized dna produced rosettes. the longest fibers and the most symmetric rosettes were observed in amphibian nuclear spreadings. in this procedure purified nuclei were submitted immediately to kleinschmidt spreading over various types of hypophase. ...19836418477
analgesic effects of ethylketocyclazocine and morphine in rat and toad.we have previously found rat and toad (bufo marinus) brain to contain inverse ratios of benzomorphan-preferring (kappa/sigma) and morphine-preferring (mu) opioid receptor types. the aim of the present study was to compare in vivo pharmacologic activity of a benzomorphan, ethylketocyclazocine (ekc) and morphine sulfate (ms) in rat and toad. footshock intensity thresholds for eliciting locomotion were determined and dose-response curves for ekc and ms analgesia were obtained. drugs were injected s ...19846433131
rapid embedding of tissues in lowicryl k4m for immunoelectron microscopy.lowicryl k4m (k4m) was recently introduced as an embedding medium for immunocytochemistry at the electron microscope level (bl armbruster, e carlemalm, r chiovetti, rm garavito, ja hobot, e kellenberger, w villiger (1982):j microsc 126:77 and e carlemalm, m garavito, w villiger (1982):j microsc 126:123). while earlier protocols of fixation and embedding required 4-6 days, the present method has reduced the processing time by accelerating both dehydration of tissues and polymerization of k4m so t ...19846436366
occurrence and experimental infection of toads (bufo marinus and b. granulosus) with mycobacterium chelonei subsp. a survey of 234 amazonian toads and frogs, six strains of mycobacterium chelonei subsp. abscessus were isolated from the liver or spleen of four of 66 bufo marinus (6.1%) and from the kidney or peritoneal fluid of two of 86 b. granulosus (2.3%). there were no histopathological lesions in the viscera of the infected animals. experimental infection of 29 captive b. marinus and b. granulosus, by the intraperitoneal route, with a pooled inoculum of m. chelonei subsp. abscessus caused five deaths ...19846438324
ammoniuretic activity of dog plasma when tested on urinary bladder of bufo marinus. 19806773053
amiloride inhibits mammalian renal kallikrein and a kallikrein-like enzyme from toad bladder and skin.renal kallikrein is localized in luminal plasma membranes of the mammalian distal nephron and gains access to urine from this site. its activity is regulated, in part, by aldosterone. these facts led us to study the effects of amiloride, a drug known to inhibit sodium reabsorption and potassium secretion at this site, on kallikrein activity. amiloride inhibited the esterolytic activity of purified rat or human urinary kallikrein or of rat renal cortical cells upon a synthetic substrate (id50 = 0 ...19806773984
detergent-based isolation of marginal bands of microtubules from nucleated erythrocytes.we have developed a new, detergent-based method for the isolation of marginal bands (mbs) of microtubules from non-mammalian vertebrate erythrocytes. the critical step in mb isolation is selective removal of the "membrane skeleton" network (ms), within which the mb is enclosed. to test potential ms solubilizing agents systematically, we prepared dogfish (mustelus canis) erythrocyte cytoskeletons in the presence of protease inhibitors and stored them at -20 degrees c in medium containing 50% glyc ...19902127917
aldosterone-induced proteins in renal epithelia.similar aldosterone-induced proteins have been demonstrated in two renal epithelia, the urinary bladder of the toad, bufo marinus, and epithelia formed by cells of the a6 line derived from the kidney of the toad, xenopus laevis. the proteins are induced along with the stimulation of na+ transport but their synthesis is not dependent on na+ transport per se. in view of the similar characteristics of the aldosterone-induced proteins in these two different epithelia, we suggest that they may have a ...19826816293
amphibian neurotensin (nt) is not xenopsin (xp): dual presence of nt-like and xp-like peptides in various clarify whether xenopsin (xp) is the amphibian counterpart of mammalian neurotensin (nt), extracts of skin, brain, and intestine from representative amphibians were subjected to immunochemical, chromatographic, and biological analyses. the results indicated the dual presence of nt- and xp-like peptides in extracts of tissues from xenopus laevis, rana catesbeiana, rana pipiens, bufo marinus, bufo americanus, and necturus maculosus, which were separated during gel chromatography on sephadex g-2 ...19826977439
a fluorescent analogue of hydrin 1: a new probe for vasotocin receptors.hydrin 1 is the biosynthetic precursor of vasotocin in xenopus laevis. we have synthesized deamino and fluorescein analogues of hydrin 1 and characterized their physiological action in the urinary bladder of the toad, bufo marinus. 1-deamino-hydrin 1 (d-hydrin) was more potent than vasotocin in stimulating osmotic water flow across intact bladders and more potent than vasotocin in displacing tritium-labeled vasopressin [( 3h]avp) from cell membranes. 1-deamino-[11-lysine (fluorescein)]-hydrin 1 ...19902121046
the changing distribution of neurons in the inner nuclear layer from metamorphosis to adult: a morphometric analysis of the anuran retina.the generation and changing distribution of neurons of the inner nuclear layer (inl) in the retina of two anuran species, bufo marinus and xenopus laevis, were studied from metamorphosis to adult. morphometric studies were undertaken at six developmental stages in bufo and four in xenopus. the number and thickness of neurons in the inl were established in 29 predetermined retinal locations from serial sections of the eyes cut vertically or horizontally. the total number of neurons in the inl inc ...19902118741
interphotoreceptor retinoid-binding protein promotes rhodopsin regeneration in toad photoreceptors.interphotoreceptor retinoid-binding protein (irbp) has been hypothesized to function as an intercellular shuttle in the vertebrate eye, serving to transport retinoids between the retinal pigment epithelium (rpe) and photoreceptors in the process by which visual pigment is regenerated after photolysis. this hypothesis was tested in preparations utilizing the toad (bufo marinus) eye and purified, initially ligand-free irbp obtained from the bovine eye. rod outer segments (ros) or neural retinas we ...19902118660
the distribution and colocalization of neuropeptides and catecholamines in nerves supplying the gall bladder of the toad, bufo marinus.the indirect immunofluorescence technique was used to determine the distribution of peptide-containing axons in the gall bladder of the cane toad, bufo marinus. in addition, the adrenergic innervation of the gall bladder was examined by use of immunoreactivity to the catecholamine-synthesizing enzyme, tyrosine hydroxylase, and glyoxylic acid-induced fluorescence. on the basis of peptide coexistence, two intrinsic populations of neurones and their projecting fibres could be distinguished substanc ...19947914471
m-wave of the toad electroretinogram.1. in the retina, two distinct, light-evoked releases of k+ have been described. one takes place in the outer plexiform layer (opl) and is termed the "distal k+ increase." the other takes place in the inner plexiform layer (ipl) and is termed the "proximal k+ increase." although the distal k+ increase generates the electroretinogram (erg) b-wave, the contribution of the much larger proximal k+ increase to the erg is less well understood. in this paper we detail our investigation of the proximal ...19911812226
the contralaterally projecting neurons of the isthmic nucleus in five anuran species: a retrograde tracing study with hrp and cobalt.the morphology of projection neurons of the isthmic nucleus was studied in rana esculenta, r. nigromaculata, bufo marinus, b. bufo gargarizans, and xenopus laevis from a comparative anatomical point of view. the main point of this work was to provide an anatomical basis for electrophysiological studies. neurons projecting to the ipsilateral optic tectum were labeled by retrograde transport of horseradish peroxidase and cobaltous lysine complex injected into the optic tectum. contralaterally proj ...19947962721
changes in whole-body thyroxine and triiodothyronine concentrations and total content during early development and metamorphosis of the toad bufo marinus.this study describes changes in the thyroid hormones thyroxine (t4) and triiodothyronine (t3) in the toad bufo marinus during development from early embryonic stages through metamorphosis. both the total content and concentrations of t4 and t3 were calculated to assess whether changes in these hormones might derive from changes in body mass or water content rather than from changes in hormone production or metabolism. three clutches of eggs were collected from ponds during the day following fert ...19948045369
plasma potassium may protect sodium pumps of toad hearts from an endogenous inhibitor.resibufogenin (3-hydroxy-14,15-epoxy-20,22-dienolide glycoside) is a potent sodium pump inhibitor present in toad toxin. it is present in the skin of the cane toad (bufo marinus) at a concentration equivalent to ouabain of approximately 1 mm. because toads, like other amphibians, have permeable skin, resibufogenin is also found in high concentrations in the blood. in the cane toad the blood concentration is estimated to be 1 microm (d. lichtstein, s. kachalsky, and j. deutsch. life sci. 38: 1261 ...19948092319
functional properties of interphotoreceptor retinoid-binding has been hypothesized that interphotoreceptor retinoid-binding protein (irbp) functions as a two-way carrier of retinoid between the retinal pigment epithelium (rpe) and rod photoreceptors in the vertebrate eye. this hypothesis has been tested in recent studies that have employed purified, initially ligand-free, bovine irbp and the "rpe-eyecup" obtained from the toad (bufo marinus) eye. the present experiments further characterize the irbp/rpe-eyecup system with respect to (i) the solubilizat ...19911775528
synaptic contacts of serotonin-like immunoreactive and 5,7-dihydroxytryptamine-accumulating neurons in the anuran retina.the synapses of serotonin-like immunoreactive retinal neurons were studied in bufo marinus and xenopus laevis and those of 5,7-dihydroxytryptamine-labelled cells in xenopus. immunoreactivity to serotonin was mostly confined to amacrine cells. synapses formed by profiles of labelled cells were almost uniformly distributed in the inner plexiform layer in both species. interamacrine synapses were the most frequent, and in some cases two labelled amacrine cell profiles made a gap junction. some of t ...19938341421
species and tissue distribution of the regulatory protein of glucokinase.rat liver is known to contain a regulatory protein that inhibits glucokinase (hexokinase iv or d) competitively versus glucose. this inhibition is greatly reinforced by the presence of fructose 6-phosphate and antagonized by fructose 1-phosphate and by kcl. this protein was now measured in various rat tissues and in the livers of various species by the inhibition it exerts on rat liver glucokinase. rat, mouse, rabbit, guinea-pig and pig liver, all of which contain glucokinase, also contained bet ...19938373368
serotonin synthesis and accumulation by neurons of the anuran retina.serotonin-synthesizing and serotonin-accumulating neurons were studied in the retinas of xenopus laevis and bufo marinus. all previously identified cell types exhibiting serotonin-like immunoreactivity (sli) were labeled by intravitreal injection of 5,7-dihydroxytryptamine (5,7-dht). they included two amacrine cell types (large and small) in both species, and one bipolar cell type in xenopus. incubation of retinas in culture medium in the ambient light reduced sli in amacrine cells and enhanced ...19921390395
comparative enzymology of amp deaminase, adenylate kinase, and creatine kinase in vertebrate heart and skeletal muscle: the characteristic amp deaminase levels of skeletal versus cardiac muscle are reversed in the north american toad.the specific activity of three characteristic enzymes, adenylate deaminase, adenylate kinase, and creatine kinase, in the skeletal muscles and heart of a variety of vertebrate land animals, including the human, are surveyed. data from this study and available studies in the literature suggest that adenosine monophosphate deaminase in land vertebrates is quite high in white skeletal muscle, usually somewhat lower in red muscle, and 15- to 500-fold lower in cardiac muscle. adenosine monophosphate ...19938394393
phosphorylation of na,k-atpase alpha-subunits in microsomes and in homogenates of xenopus oocytes resulting from the stimulation of protein kinase a and protein kinase c.the phosphorylation of the alpha-subunit of na+/k(+)-transporting atpase (na,k-atpase) by camp-dependent protein kinase (pka) and protein kinase c (pkc) was characterized in purified enzyme preparations of bufo marinus kidney and duck salt gland and in microsomes of xenopus oocytes. in addition, we have examined camp and phorbol esters, which are stimulators of pka and pkc, respectively, for their ability to provoke the phosphorylation of alpha-subunits of na,k-atpase in homogenates of xenopus o ...19921331053
nitric oxide synthase immunoactivity and nadph diaphorase enzyme activity in neurons of the gastrointestinal tract of the toad, bufo marinus.the presence of nitric oxide synthase (nos) was demonstrated immunohistochemically, and nadph diaphorase was demonstrated by enzyme histochemistry in neurons throughout the gastrointestinal tract of the anuran amphibian, bufo marinus. successive staining showed that nos immunoreactivity and nadph diaphorase activity occurred in precisely the same subgroup of enteric neurons. subsequent detailed studies of the distribution of these neurons were made using nadph diaphorase histochemistry. numerous ...19921282824
cyclicity and memory in the humoral immune response of the marine toad bufo marinus.bufo marinus toads immunized with a single dose of 100 mug of polymerized flagellin (pol) produce a longlasting cyclic humoral response at 22 degrees c in which the serum antibody titers rise and fall within periods of 2-3 weeks. this seems to be regulated by the catabolism of immunoglobulins, since passive 125i-labeled igm in the serum has a half-life of 17 days, corresponding to the cyclicity of the titers of active antibodies. in toads injected with between 10 ng and 10 mug antigen the serum ...1976825371
disproportionate distribution of field potentials across the toad's tectal visual map in response to diffuse light on and off 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 ...19968746239
electrical responses of rods in the retina of bufo marinus.1. intracellular responses to flashes and steps of light have been recorded from the outer segment and the cell body of rods in the retina of the bufo marinus. the identification of the origin of recorded responses has been confirmed by intracellular marking.2. responses to flashes delivered in darkness or superimposed on a background were analysed. responses recorded from outer segments conform to the principle of ;spectral univariance'. the shape of the response is not affected by enlarging th ...1977406383
tazonomy of toxoplasma.after reviewing reports of the hosts, structure and life cycle of toxoplasma, the genus is placed in the apicomplexan family eimeriidae and the folllowing 7 species are recognized: toxoplasma gondii (nicolle & manceaux) (type species) from about 200 species of mammals and birds, with oocysts in felids; toxoplasma alencari (da costa & pereira) from the frog leptodactylus ocellatus; toxoplasma brumpti coutelen from the iguana iguana tuberculata; toxoplasma colubri tibaldi from the snakes coluber m ...1977325203
thyroxine and na+ transport in toad: role in transition from poikilo- to homeothermy.the effects of thyroxine (t4) on na+ transport, oxygen consumption (qo2), and na+-k+-atpase activity were studied in the urinary bladder and liver of the toad bufo marinus. in the bladder, t4 in vitro (10(-8) to 10(-6) m) had no significant effect on these parameters during 15 h of incubation. when injected intraperitoneally (approximately 20 microgram/(kg body for 6 days), t4 lowered base-line, short-circuit current by 62% (p less than 0.0025) and potential difference by 37% (p less tha ...1979218460
the effect of galanin and galanin fragments on blood pressure in the cane toad, bufo marinus.galanin has previously been shown to have a slight vasodepressor or no effect on blood pressure in placental mammals, but causes potent increases in blood pressure in several other vertebrate species. in this paper, the part of the galanin molecule responsible for the pressor activity was investigated in the cane road, bufo marinus by administration of fragments of galanin into anaesthetised toads and isolated arterial segments in an organ bath. in anaesthetised toads, the order of efficacy was ...19968988515
effect of three galanin antagonists on the pressor response to galanin in the cane toad, bufo marinus.galanin is a neuropeptide that causes a marked pressor response in several non-mammalian vertebrate species, and some marsupials. in this study, the effect of three galanin antagonists were tested on the pressor response to an intravenous dose (6.3 nmol/kg) of porcine galanin in anaesthetised cane toads, bufo marinus. antagonists were injected at either 20 or 50 times the molar dose (x md) of galanin. the antagonist, c7 (galanin 1-13-spantide) reduced the pressor effect of galanin by 32.2 +/- 6. ...19968988516
[molecular and functional diversity of na,k-atpase and renal h,k-atpases].potassium homeostasis is a determinant factor in the maintenance of many vital functions. cell excitability, for instance, in striate and cardiac muscle, as well as in neurons, is dependent upon the ratio of potassium levels on either side of the plasmic membrane. acute or chronic mechanisms of adjustment to disorders of bodily potassium balance exist in muscle, the kidney and distal colon. na+k(+)-atpase is involved in potassium transfers between the extracellular and intracellular compartments ...19969019667
aerobic and anaerobic metabolism of the crystalline lens of a poikilotherm; the toad bufo marinus.1. the o2 consumption and lactic acid production of the lens of the toad bufo marinus was measured under various conditions. the energy consumption was very low compared to other amphibian tissues and about 20% of that previously described in the rat lens. about 80% was derived from oxidative metabolism, which is the converse of that seen in mammals. 2. cyanide abolished o2 consumption and increased lactate production 20-30 times ("pasteur effect"). 3. under aerobic conditions about 40% of the e ...1979122582
the neuropharmacology of a novel gamma-aminobutyric acid analog, kojic amine.kojic amine (ka; 2-aminomethyl-5-hydroxy-4h-pyran-4-one), a compound which shares some structural features with gamma-aminobutyric acid (gaba) and muscimol, has been examined in a variety of test systems for gabamimetic activity. in several in vitro central nervous system receptor binding assays employing rat brain membrane preparations, ka exhibited selective activity to displace 3h-muscimol but with a relatively high ic50 of 4.4 mum. ka did not alter the binding of 3h-diazepam. iontophoretical ...1979118713
effects of bufo marinus skin toxins on human fetal extracorporeal blood vessels.the effects of extracts of bufo marinus toad skin toxin on human isolated umbilical arterial rings and the fetal vessels of perfused placentae were examined and compared with those of ouabain, an inhibitor of na+/k(+)-atpase. umbilical artery rings and fetal vessels of the perfused placenta responded to extracts, or ouabain, with constriction which persisted after the removal of each agent. extraction of the skin, using various solvents, revealed that the umbilical artery constriction was due ma ...19979080586
comparative immunology: the hemolytic complement system of the anuran amphibian, bufo marinus. 19714396820
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