| repetitive dna and feulgen hydrolysis kinetics in three species of bufo. | two north american species of the genus bufo (bufo cognatus and bufo boreas, 2n = 22) and one african species (bufo regularis, 2n = 20) were analyzed with respect to their repetitive dna fractions and the behaviour of their chromatin to the acid hydrolysis at different times. the mean melting point of the total isolated dna decreased from 89 degrees c to 87 degrees c with a genome size increase from 4.4 to 7.5 pg. the differences in genome size can only partly be explained on the basis of repeti ... | 1979 | 93962 |
| [measurement of the variations of cytoplasmic and nuclear volumes of the absorbing cells of the digestive tube according to the nutritional conditions, in the larva of the common toad (bufo bufo l.)]. | | 1978 | 98945 |
| [analysis of the tissue interactions responsible for the mesonephogenic determination in amphibians, by the in vitro culture technic]. | the cultivation of mesonephric lateral mesoblast, in combination with the dorso-caudal endoblast, with or without cordomesoderm, leads to the differentiation of mesonephric tubules in bufo bufo and pleurodeles waltlii. then, the nephric duct does not seem to be necessary to nephric differentiation under in vitro cultivation conditions. | 1978 | 100240 |
| clustered and interspersed repetitive dna sequences in four amphibian species with different genome size. | we have compared the amount of clustered and interspersed repetitive sequences in the genome of four amphibia with different dna contents per haploid nucleus: two anura (xenopus laevis, 3 pg and bufo bufo, 7 pg) and two urodela (triturus cristatus, 23 pg and necturus maculosus, 52 pg). high molecular weight dna of the four species was denatured and reassociated to the same cot in order to obtain duplex sequences with a similar reiteration frequency. single-stranded dna was digested off with the ... | 1978 | 101246 |
| the distribution of sodium, potassium and chloride in the nucleus and cytoplasm of bufo bufo oocytes measured by electron microprobe analysis. | 1. measurements of cytoplasmic and nuclear na, k and cl have been made by electron microprobe analysis on freeze-dried sections of oocytes of bufo bufo, using standards of bovine plasma albumin and gamma-globulin. concentrations were obtained per kilogram of dry mass, were converted to concentrations per litre of water content using known figures for water and solid concentration of nucleus and cytoplasm, and were then compared with measurements on cells from the same animal obtained by flame ph ... | 1978 | 104029 |
| effects of human chorionic gonadotropin and salmon gonadotropin on testis in hypophysectomized toads (bufo bufo bufo l.). | | 1978 | 105961 |
| [vascularization of the hypothalamic-hypophyseal area of the toad bufo bufo (l.). light and scanning electron microscopy studies]. | | 1978 | 106569 |
| invariants in configurational prey selection by bufo bufo (l.). | toads (bufo bufo) are able to distinguish small stripes with axis orientation in the direction of motion (worm-like stripes) from those with axis orientation perpendicular to the direction of motion (anti-worm-like stripes). the configurational discrimination ability of the toad is, thus far investigated, largely invariant for (1) movement direction in the x-y plane, (2) direction of contrast--stripe against background--and (3) velocity of stripe motion. | 1979 | 106924 |
| effects of unilateral ovariectomy on growth of oocytes in the ovaries of adult toads (bufo bufo bufo l.). | | 1979 | 110364 |
| [early organization of the dermatome and of the sclerotome in 2 anura amphibias rana dalmatina bon. and bufo bufo l]. | | 1978 | 111809 |
| influence of thyroid hormone on the development of peoptic-hypothalamic monoaminergic neurons in tadpoles of bufo bufo japonicus. | the effect of thyroid hormone on the development of diencephalic monoaminergic neurons was studied in tadpoles of bufo bufo japonicus. monoamine-containing neurons in the preoptic recess organ (pro) appeared later than those in the paraventricular organ (pvo) and nucleus infundibularis dorsalis (nid). after deprivation of thyroidal primordium no fluorescent neurons developed in the pro. development of monoaminergic neurons in the pvo and nid was not affected by thyroidectomy. thyroxine treatment ... | 1979 | 113102 |
| configurational prey selection by bufo, alytes, bombina and hyla. | the aim of the present study is to answer the following questions; (1) is the ability of toads to distinguish between different configurational prey stimuli based on learning during ontogeny? (2) is the configurational meaning of a stimulus influenced by its distance from the animal? (3) are there differences in configurational prey selection among different anuran species? (1) experiments with postmetamorphic juveniles of alytes obstetricans indicate that preferences for worm-like objects can b ... | 1979 | 114268 |
| [analysis of the structural features of the sperm chromatin of amphibia]. | deoxyribonucleoproteid (dnp) organisation of the sperm from amphibian species (rana temporaria, triturus vulgaris, bufo bufo) with different sperm chromosomal basic proteins has been analysed by nuclease fragmentation. electrophoretic distribution of chromatin fragments reveals regular organisation of dnp in the sperm of the species investigated. in spermal dnp of the frog rana temporaria, 3 sub-fractions of histone h1 were found. in the sperm of the newt triturus vulgaris and the toad bufo bufo ... | 1979 | 116455 |
| [cholinergic and adrenergic innervation of the arteries of the base of the brain in certain lower vertebrates]. | the arteries in the encephalon base have been investigated by koelle's and falck's methods in teleostei (anarhichas lupus, eleginus navaga, leuciscus brandti, pelingas), amphibians (rana temporaria, rana semiplicata, bufo bufo) and in reptiles (testudo horsfieldi, trionyx chinensis). cholin- and adrenergic nerve fibres of the encephalic arteries have been revealed in all the vertebrates studied, but their concentration is far from being equal. in fishes and reptiles neural conductors from scarse ... | 1979 | 116627 |
| light and scanning microscopy of the tongue and its gustatory organs in the common toad, bufo bufo (l.). | unlike frogs and european tree frogs, the common toad bufo bufo possesses a tongue lacking filiform papillae on its dorsal surface. instead, the mucosal epithelium forms irregular, high folds, dividing the surface of the tongue into numerous separate compartments. at the bottom of those compartments occur openings of tubular glands and singular ciliated cells. in a strongly distended tongue the folds of mucosa disappear, and the regions of glandular orifices assume a shape of pocket-like recesse ... | 1979 | 117649 |
| [myelinogenesis of the central nervous system of the larvae of bufo bufo]. | | 1978 | 118714 |
| [ultrastructural aspects of the organization of somites and the early differentiation of myotomes in the embryo of the common toad bufo bufo l]. | | 1979 | 121682 |
| rejection of skin allografts in the common toad, bufo bufo l. | | 1979 | 121972 |
| [parasitism of larvae of the fly, lucilia bufonivora, moniez, 1876, on anura]. | in 1951 to 1973 there were recorded cases of myiasis in four species of amphibia (pelobates fuscus, bufo bufo, b. viridis, rana arvalis) from the volga-kama state reserve (the tatar assr). in arid 1972 the number of rana arvalis with myiasis reached to 20-25%. observations were conducted on the development of lucilia bufonivora from the egg laying to the host death and hatching of imago. | 1976 | 134338 |
| [neuromuscular spindles of several amphibia and reptiles]. | the work presents data on the structure and innervation of the nerve-muscle spindles in the soleus of the lake from rana ridibunda, bufo bufo, turtle testudo horsfieldi, lizzard lacerta agilis. the animals under study were shown to have different structure and innervation of these receptors. the thickness of the spindle connective tissue capsule has certain correlation with the width of the subcapsular space. the innervation apparatus in the muscle spindles of reptiles and turtles are similar in ... | 1976 | 136238 |
| research on cholesterol, steroidal hormones and liposoluble vitamins by thin layer chromatography in some adipose organs of anuran amphibians. ii. liposoluble vitamins. | by means of thin layer chromatography and selective detection, vitamin a acetate, vitamin e and vitamin e acetate, vitamin d3 and cholesterol were identified in the prepericardic body, adrenal tissue, fat bodies and testis of bubo bufo, as well as in the prepericardic body of rana esculenta. on the contrary, liposoluble vitamins could not be isolated from the adipose tissue occurring in the thoracic cavity of rana esculenta, or in bufo bufo muscles. the results are discussed in correlation with ... | 1976 | 218524 |
| the excretion of hydrogen ion by the isolated amphibian skin: effects of antidiuretic hormone and amiloride. | h+ extrusion by the isolated skins of two amphibia, rana ridibunda and bufo bufo, was studied in order to test for the presence of exchange mechanisms of the type na+/h+ and cl-/hco3-, which have been described in several epithelial structures. the preparations were mounted in chambers of the ussing type, so that the short-circuit current could be used as a function of na+ transport and the ph-stat techinique was utilize to determine the rates of h+ extrusion under different experimental conditi ... | 1975 | 235991 |
| effects of dehydration, vasotocin and hypertonicity on net water flux through the isolated, perfused pelvic skin of bufo bufo bufo (l.). | | 1975 | 236889 |
| incorporation of 3h-thymidine in stratum germinativum of epidermis in the toad bufo bufo bufo (l): an autoradiographic study of moulting cycle and diurnal variations. | | 1975 | 240566 |
| late hexokinase activity expression during bufo bufo development. | hexokinase activity was detected in cytosols and homogenates from different developmental stages of bufo bufo embryos starting from stage 17. free glucose was measured in the embryo cytosol and was detected at each stage tested. at stage 15, a large increase of glucose content of the embryo cytosol occurs. hexokinase expression in the embryo thus occurs after the increase of cytosol glucose content occurring at stage 15. the findings rule out that glucose by itself is the hexokinase inducer in v ... | 1977 | 402952 |
| vascularization of the pars distalis of the hypophysis in the toad, bufo bufo (l.) (amphibia, anura). a comparative light microscopical and scanning electron microscopical study. i. | the vascularization of the pars distalis of the hypophysis of the toad, bufo bufo (l.), was studied by the traditional method of injecting a mixture of india-ink and gelatine into the circulatory system of the head via the arteria coratis communis. further, methyl-methacrylate corrosion casts of the brains were made; the hypothalamo-adenohypophysial region of these corrosion casts was studied with the scanning electron microscope. the results showed that the portal vessels which arise from the m ... | 1977 | 404041 |
| vascularization of the pars intermedia of the hypophysis in the toad, , bufo bufo (l.) (amphibia, anura). a comparative light microscopical and scanning electron microscopical study. ii. | the vascularization of the pars intermedia of the hypophysis of the toad, bufo bufo (l.) was studied by injection of a mixture of india-ink and gelatine into the circulatory system of the head via the arteria carotis communis. further methyl-methacrylate corrosion casts of brains were made and the hypophysial region of the corrosion casts was examined with the scanning electron microscope. the results showed that the vascularization of the pars intermedia of the toad hypophysis consists of a sin ... | 1977 | 404042 |
| the vascularization of the neural stalk and the pars nervosa of the hypophysis in the toad, bufo bufo (l.) (amphibia, anura). a comparative light microscopical and scanning electron microscopical study. | the angioarchitecture of the neural stalk and the encephaloposthypophysial portal system of the hypophysis of the toad, bufo bufo (l.), was studied using three different methods. the neural stalk is mainly supplied by branches of the arteria infundibularis superficialis which form a widemeshed vascular network. dorsally this network continues into the plexus of the pars nervosa. the vascularization of the pars nervosa is made up of the encephalo-posthypophysial portal system. this portal system ... | 1977 | 407002 |
| length and interspersion of repetitive and non repetitive dna sequences in four amphibian species with different genome sizes. | the interspersion period of repetitive and unique sequences was analyzed by two different methods, electron microscopy and agarose gel electrophoresis, for four amphibian species with different nuclear dna content, namely the anura xenopus laevis (3 pg dna per haploid genome) and bufo bufo (7 pg) and the urodela triturus cristatus (23 pg) and necturus maculosus (52 pg). within each of the two subclasses it has been found that interspecific differences, in dna content, due to variations in the am ... | 1977 | 407058 |
| [effect of diet on the mitotic activity and rate of cytolysis of intestinal epithelial cells in tadpoles of the common toad, bufo bufo (amphibia, anura)]. | effects of diet on the mitotic activity and cellular mortality rate of the intestinal epithelium cells have been examined in toad tadpoles. as yolk is utilized, the composition of diet has little effect on these 2 parameters. as development goes on, the cellular mortality rate increases with dietary carbohydrate, fat or protein supplementation. but only the fats affect the mitotic activity. | 1977 | 410511 |
| [consequence of heterospecific cytoplasmic graft on gastrulation of bufo bufo l. (amphibia, anura)]. | bufo bufo nuclei were grafted in virgin and enucleated bufo calamita eggs. in these conditions embryonnic development was stopped at the early gastrula stage in 92% of the recipient eggs. for accomparative analysis bufo calamita cytoplasm was injected into fertilized bufo bufo eggs and produce arrest of development at the early gastrula stage. the progressive enhancement of this development inhibition was related to the increasing of the injected cytoplasm volume. | 1977 | 410516 |
| catecholamine-secreting cells in the adrenal gland of bufo bufo during metamorphosis and in the adult. | | 1977 | 411709 |
| histochemistry of the juxtaglomerular apparatus in the toad bufo bufo. the glucose-6-phosphate dehydrogenase activity of the macula densa. | an investigation regarding the question of whether there exists a macula densa as part of the juxtaglomerular apparatus in the kidney of amphibians has been carried out. with the aid of a histochemical reaction for glucose-6-phosphate dehydrogenase activity, the presence of a macula densa zone as a specialized part of the distal tubule in the toad bufo bufo was demonstrated. the functional significance of the high glucose-6-phosphate dehydrogenase activity in the macula densa cells is discussed. | 1977 | 412593 |
| properties of a conductive cellular chloride pathway in the skin of the toad (bufo bufo). | two types of chloride current response to a step-wise hyperpolarization of the toad skin is demonstrated: (1) an "instantaneous" response observed immediately upon voltage change, and (2) a subsequent slow response, the time course of which is sigmoidal. the slow response is due to an increase of a transcellular conductance which is specific to chloride ions. the time constant of the conductance increase is dependent on the amplitude of the transepithelial voltage displacement, the smallest time ... | 1978 | 415515 |
| relation between chloride exchange diffusion and a conductive chloride pathway across the isolated skin of the toad (bufo bufo). | substitution of chloride in the outside bathing medium of the toad skin with bromide, iodide, nitrate and sulphate leads to a reduction in the apparent exchange diffusion of chloride across this tissue, and also to a reduction of the chloride current recorded during hyperpolarization. a series of inhibitors (thiocyanate, furosemide, phloretin, and acetazolamide) also affects chloride exchange diffusion, hyperpolarization current as well as chloride influx during hyperpolarization. although in so ... | 1978 | 415517 |
| [the development of urogenital organs after lateral mesoblast heterotopic graft in the toad (bufo bufo) neurula. i. distinct inversions of anteroposterior and dorsoventral axis of the lateral plate (author's transl)]. | anteroposterior inversion of lateral mesoblast of early toad neurula is followed by differentiation of diverse urogenital blastema, according to the transplant position before the graft. anteroposterior polarity of lateral mesoderm is thus perfectly determined in young neurula. on the contrary, dorsoventral inversion of lateral mesoblast leads to mesodermic blastema formation according to the transplant position after the graft. particularly, the dorsal region of the lateral plates displaced to ... | 1978 | 416162 |
| [the development of urogenital organs after lateral mesoblast heterotopic graft in the toad (bufo bufo) neurula. ii. simultaneous inversion of anteroposterior and dorsoventral axis of the lateral plate]. | simultaneous inversion of the anteroposterior and dorsoventral axes of the lateral mesoblast in the early toad neurula leads to the total agenesis of the urogenital organs. the experimental results show that the lateral mesoblast is unable to undergo self-differentiation, and that three factors at least are required for the formation of the urogenital blastemata. the mesoblast must be competent: only the posterior (dorsal, but also ventral) part of the lateral mesoderm is endowed with this compe ... | 1978 | 418132 |
| [arterial monoaminocytes of the base of the brain in vertebrates]. | by falck's method monoaminocytes of the arteries in the encephalon base were studied in teleostei (anarhichas lupus, eleginus navaga, leuciscus brandti liza soiuy in amphibians (rana temporaria, rana semiplicata, bufo bufo), in reptiles (testudo horsfiedli, trionyx chinensis) and in birds (blue rock pigeon, hen). specific and individual peculiarities in chromaffinocyte, labrocyte and melanophore distribution were revealed in the vertebrate cranial arteries. in all the animals studied chromaffin ... | 1979 | 518336 |
| [organization and differentiation of the segmentary plate in common toad embryo bufo bufo l., following heat shock (author's transl)]. | a heat shock greatly disturbs the shaping and the growth of embryos with 4 or 5 somites. one part of a segmentary plate with a size including four control somites stays inorganized, whereas posterior segmentation gets on normally. the differentiation of the unsegmented somitic block (fusing myoblasts, myogenesis) is the same as the one of the previous somites; the dermatome and the sclerotome issued from the unsegmented block are not cut up. ultrastructural observations of treated segmentary pla ... | 1979 | 554542 |
| blood-group a and g specific structures in toad (bufo) spawn. comparative studies on three species (bufo bufo, bufo viridis, bufo calamita). | permethylation analyses of the spawn material of three toad (bufo) species allow the conclusion that the serologically determinant group in bufo bufo spawn is identical with that found in human and hog blood-group a substances (i.e. galnac(alpha1,3) [fuc(alpha1,2)] gal -), and the serologically determinant group in bufo viridis and bufo calamita spawn is identical with that found in blood-group h substances (i.e. fuc(alpha1,2) gal -). | 1978 | 569402 |
| protein content of ribosome subunits during bufo bufo development. | | 1979 | 574348 |
| effects of ergocornine and reserpine on metamorphosis in bufo bufo japonicus tadpoles. | effects of ergocornine and reserpine on tail resorption during metamorphosis in bufo bufo japonicus tadpoles were studied. at prometamorphosis, ergocornine induced precocious tail resorption, while reserpine scarcely affected the tail size. at the climax of metamorphosis, ergocornine was almost ineffective in accelerating tail resorption, while reserpine was effective in inhibiting tail resorption. since prolactin-like hormone is known to block the tail resorption induced by thyroid hormones, it ... | 1979 | 583463 |
| [phylogenetic studies on some japanese amphibia by means of immunoelectrophoresis. ii. relationships of some amphibians to japanese pond frogs (author's transl)]. | since the japanese pond frogs (rana nigromaculata and r. brevipoda) are known to be very closely allied with each other in morphological, ecological, physiological or immunological characters, the phylogenetical relationships between the japanese pond frogs and other 10 species of japanese amphibians were investigated by means of immunoelectrophoretic analysis of liver extract. the results obtained are as follows: (1) there are conservative antigens which are commonly found in all species of anu ... | 1978 | 631194 |
| effects of hypophysectomy on structure and function of testis in adult toads, bufo bufo bufo (l.). | | 1978 | 631541 |
| effect of season, temperature acclimation and starvation upon plasma ffa and glycerol levels in the frog, rana temporaria, and in the toad, bufo bufo. | | 1975 | 804377 |
| fine structure of the male genital tract and kidney in the anura xenopus laevis daudin, rana temporaria l. and bufo bufo l. under normal and experimental conditions. | the ultrastructure of the main cellular components of testicular interstitial spaces in three anuran species was studied during two short periods of the seasonal cycle and after treatment with 5- and 6-hydroxydopamine (5- and 6-ohda). in early december when seminiferous tubules are completely filled with resting spermatozoa in rana, leydig cells display a well developed smooth- and rough-surfaced er, numerous granular vesicles being untypical of mammalian leeydig cells, metochondria with tubular ... | 1975 | 805666 |
| sodium fluxes in single amphibian oocytes: further studies and a new model. | 1. the kinetics of na efflux were studied in oocytes of bufo bufo, rana temporaria and r. pipiens. 2. rate constants for na efflux into ringer solution varied from 0-002 min-minus 1 to 0-017 min-minus 1 and did not vary significantly from one species to another. 3. na efflux is rapidly reduced by 30-50% on removing external k or applying ouabain but is reduced by 90% on cooling to 0 degrees c. the effects of k and cooling are also rapidly reversible. 4. substitution of external na by li produces ... | 1975 | 805838 |
| the electric potential change of internal membrane during propagation of contraction in skinned fibre of toad skeletal muscle. | with skinned fibres prepared by removing sarcolemma in liquid paraffin from single fibres isolated from m. adductor magnus, m. sartorius or m. rectus internus major of toad (bufo bufo japonicus), it was determined whether or not an action potential ("internal action potential", or iap) could be detected during a propagated contraction evoked by electrical square pulses of 1 msec duration. the iap less than 10 mv was recorded with a glass capillary microelectrode inserted into the skinned fibre d ... | 1975 | 806737 |
| permeability pathways for non-electrolytes through bufo bufo gall-bladder. | amphotericin b treatment increases the thiourea, d-xylose and mannitol fluxes and lowers those of urea, n-methyl-urea, acetamide, formamide, and n-n'-dimethyl-thiourea. the degree of flux inhibition is related to the cellular permeability of these compounds. most probably amphotericin b increases the permeability of all those molecules across the luminal plasma membrane, but simultaneously elicits a cellular swelling, which reduces the diffusion across the lateral plasma membranes. this effect m ... | 1975 | 806888 |
| structure of the toad epidermis during the moulting cycle. ii. electron microscopic observations on bufo bufo (l.). | changes in the ultrastructure of the toad epidermis during the moulting cycle are described on the basis of 17 skin preparations fixed in consecutive phases of the cycle. our previous light microscopical findings that morphological changes are mainly restricted to a short period prior to and after shedding are confirmed. differentiation of zonulae occludentes in the new replacement layer after shedding is described and discussed in relation to the changes in ion permeability after the moult. cha ... | 1975 | 807330 |
| innervation of the male genital tract and kidney in the amphibia, xenopus laevis daudin, rana temporaria l., and bufo bufo l. | the innervation of the male genital tract and kidney in three anuran species was studied by the fluorescence histochemical method of falck-hillarp for the demonstration of monoamines whose identity was secured by thin-layer chromatography, and by electron microscopy including administration of 5- or 6- hydroxydopamine (5- and 6-odha). the genital tract comprises testis, intra- and extratesticular and intrarenal seminal efferent ducts, bidder's canal, renal dorsal transverse ducts, and ureter. in ... | 1975 | 807332 |
| [phylogenetic studies on some japanese amphibia by mean of immunoelectrophoresis. i. relationships of some frogs and newt to toad (author's transl)]. | the phylogenetic relationship among toad, frogs and newt from japan was investigated by means of immunoelectrophoresis. homologous, heterologous and non-identity reactions between rabbit anti-bufo bufo antiserum and antigen from each of 13 species and 2 subspecies of japanese amphibia were examined. the number and positions of arcs appeared in these reactions were compared. the relationship observed in the comparison well coincided with the classification of the upper taxa of amphibia; viz 1) hy ... | 1975 | 808417 |
| light- and scanning electron microscopical studies of the hypothalamo-adenohypophysial portal vessels of the toad bufo bufo (l.). | the vascularization of the hypothalamo-adenohypophysial region of the toad bufo bufo (l.) (amphibia, anura) was studied by means of light- and scanning electron microscopy. special attention was given to the portal vascular system of the median eminence and the pars distalis. course and arrangement of these vessels are described. | 1975 | 809140 |
| [constancy of color perception in the gray toad (bufo bufo l.)]. | colour vision and constancy of colour perception in bufo bufo l, were examined by means of unconditioned reaction of choosing moving and stationary models of females by males during breeding season. the males chose blue and dark blue models. control of the choice of blue models presented in pairs with models of different shades of grey proves the existence of colour vision in bufo bufo l. the choice of blue models has been observed under significantly varying conditions: both with artificial ill ... | 1975 | 813414 |
| specific activities of 6-phosphogluconate dehydrogenase, glucose-6-phosphate dehydrogenase and glucose-6-phosphate isomerase during bufo bufo development. | it has been suggested by some authors that during amphibian development, due to the higher glucose-6-phosphate dehydrogenase (ec 1.1.1.49) activity compared to that of 6-phosphogluconate dehydrogenase (ec 1.1.1.43), 6-phosphogluconate could accumulate in the embryo tissues and regulate the channelling of glucose-6-phosphate into glycolysis. here, on the base of the specific activities of glucose-6-phosphate dehydrogenase, 6-phosphogluconate dehydrogenase and glucose-6-phosphate isomerase (ec 5.3 ... | 1976 | 813778 |
| [ultrastructure aspects of myoseptum formation in embryos of the common toad bufo bufo l. (amphibia, anoura)]. | the formation of myosepts of the toad is characterized by three stages in early development. at the first stage, the somitic cells give off some pseudopods and many collagen fibres. at the second stage, the newwork of collagen fibers grows denser but pseudopods retract. in the end, at the third stage, the collagen fibres disappear and secreting fibroblasts are seen in the myosepts. | 1975 | 813885 |
| [the effects of anterio-posterior and dorso-ventral inversions of the lateral mesoblast of the neurula on the formation of the mesonephric, medullary, and adrenal anlage of the common toad, bufo bufo l. (amphibia, anoura)]. | the experimental results of cranio-caudal reversal and dorso-ventral reversal of the lateral mesoblast of the toad early neurula prove that, at this stage, the cranio-caudal polarity of this tissue is fixed but not the dorso-ventral one. external factors are responsible for the formation of mesonephric, adrenal and gonadal medullary anlage by the lateral mesoblast. | 1975 | 813886 |
| [method of determining visual pigments in situ and their study in some vertebrates]. | a simple electrophysiological method for determining of visual pigments in isolated retina is described. the method is based on registration of the early receptor potential amplitude which is proportional to the visual pigment content and on measurement of the rate of the decrease of this amplitude under the action of the bleaching light of a known wavelength and intensity. the results of the determining of rod and cone visual pigments in the lamprey lampetra fluviatilis, teleosts diplodus annul ... | 1975 | 814749 |
| [a comparative electron microscopic study of the peripheral blood leukocytes of vertebrates]. | the ultrastructure of leukocytes of the peripheral blood was studied in representatives of classes of fishes (cyprinus carpio), amphibia (rana redibunda, bufo bufo), reptiles (testudo horshfield), birds (columba livia) and mammals (rattus norvegicus). the granules are characterized by homogeneous or heterogeneous matrix. the granules of special leukocytes (turtle) and pseudoesinophils (pigeon) have larger dimensions than those in neutrophils of other animals. the matrix of the eosinophil granule ... | 1975 | 818982 |
| [conseqquences of dorso-ventral and anterior-posterior reversion of early neurula lateral mesoblast on development of urogenital system in common toad, bufo bufo. (amphibia anura)]. | at early neurula stage of the toad, cranio-caudal and dorso-ventral reversal of lateral mesoblast is performed. the genito-urinary system is therefore missing after this intervention. the three following factors of the formation of this system anlage are anlyzed: lateral mesoderm competence, stimulative activites of dorso-caudal endoblast on the one hand, of chordo-mesoderm on the other hand. | 1975 | 819145 |
| immunohistochemical localization and identification of the prolactin and growth hormone producing cells in the pituitary gland of the toad bufo bufo bufo (l). | | 1976 | 819322 |
| possible regulation on carbohydrate metabolism exerted by glucose-6-phosphate isomerase and glucose-6-phosphate dehydrogenase activity ratio during bufo bufo development. | | 1976 | 820150 |
| ovarian development in young toads, bufo bufo bufo (l.): effects of unilateral ovariectomy, hypophysectomy, treatment with gonadotropin (hcg), growth hormone, and prolactin, and importance of body growth. | | 1976 | 821812 |
| proceedings: the distribution of na, k and cl in bufo bufo oocytes measured by electron microprobe analysis. | | 1976 | 822148 |
| scanning electron microscopical studies of corrosion casts. the vascularization of the paraventricular organ (organon vasculosum hypothalami) of the toad bufo bufo (l.). | | 1976 | 825792 |
| dna reassociation kinetics in relation to genome size in four amphibian species. | dna reassociation kinetics were studied, by means of the hydroxyapatite chromatography method, for four species of amphibians with different nuclear dna content: xenopus laevis (3 pg dna per haploid genome) and bufo bufo (7 pg) of the anura subclass and triturus cristatus (23 pg) and necturus maculosus (52 pg) of the urodela subclass. within each subclass the two species studied were found to have about the same absolute amount of unique dna. the differences of total nuclear dna can be accounted ... | 1976 | 826380 |
| [constancy of color perception in the gray toad (bufo bufo l.): role of the surrounding background in recognition of stimulus color]. | the paper continues the previous study (1) on some aspects of toad colour vision. it deals with signs which allow the visual system of toad to recognize blue stimuli. the behavioural experiments were performed during the breeding season when males exhibited the clasping of stationary blue stimuli. it is shown that in spite of some variety of spectral compositions of light sources males clasp only blue stimuli on white surrounding background. under fixed illumination on white background males cla ... | 1976 | 827315 |
| the effect of external li on the distribution of na, k and cl in bufo bufo oocytes [proceedings]. | | 1976 | 827610 |
| a new cell type in the taste buds of anurans. a scanning and transmission electron microscopic study. | a hitherto undescribed cell type within the fungiform papillae of the tongue of the toad, bufo bufo (l.) and the taste-disks of the soft palate of bombina variegata l. was identified by means of scanning and transmission electron microscopy. this cell type is characterized by an apical protrusion carrying numerous microvilli. bundles of filaments are present in the cytoplasm of the protrusion. vesicles with electron lucent content and microtubules are present thoughout the cytoplasm of the cell. | 1977 | 922854 |
| [comparison of the formation of the mesonephric, medullary, and adrenal blastema of common toad embryos, bufo bufo l., and the clawed toad, xenopus laevis duad. (anuran amphibians)]. | | 1976 | 1022319 |
| [the differentiation of the somites in embryos of two anuran amphibians: the common toad (bufo bufo l.) and the frog (rana dalmatina bon)]. | | 1976 | 1022320 |
| factors controlling the annual ovarian cycle in the toad bufo bufo bufo (l.). | | 1975 | 1132648 |
| [a voltage-dependent potassium channel of outward rectifier type in plasma membrane of oocyte from toad, bufo bufo gargarizans]. | membrane properties of the fully-grown oocytes from toad, bufo bufo gargarizans, were studied by using voltage-clamp technique. it was found that a sustained outward current was elicited by membrane depolarization to -30 mv or more positive value. the increase of the current was nearly proportional to the degree of depolarization. the peak value of the current ranged 2-5 microa at a membrane potential of 20 mv in oocytes from different toads. the current was inhibited by antagonists of potassium ... | 1992 | 1293763 |
| [studies on the chemical constituents from the skin of bufo bufo gargarizans cantor]. | four bufotoxins were isolated by means of preparative reversed phase hplc from the water soluble fraction of the skin of bufo bufo gargarizans cantor. on the basis of their spectral data (uv, ir, 1hnmr, 13cnmr, eims and fdms), amino acid analyses and chemical properties, they were identified as bufotalin 3-succinoylarginine ester(i), bufalin 3-succinoylarginine ester(ii), cinobufagin 3-succinoylarginine ester(iii), and resibufogenin 3-succinoylarginine ester(iv). compound i is a new bufotoxin. | 1992 | 1293940 |
| [the expression of kainate and gaba receptors in oocytes of bufo bufo gargarizans]. | oocytes of bufo bufo gargarizans were used as an expression system for analyzing structure of exogenous membrane protein and their functions. poly (a)+ mrna isolated from rat brain was injected into toad (bufo bufo gargarizans) oocytes (50 ng/oocyte). rat brain kainic acid and gamma-aminobutyric acid(gaba) receptors expressed by the injected mrna were integrated in the oocyte membrane 48 h after the injection at 19 degrees c. membrane currents induced by kainic acid (5 x 10(-5) mol/l) and gaba ( ... | 1992 | 1338132 |
| relationships between feeding, digestion and water balance in a carnivorous vertebrate, the toad bufo bufo l. | 1. toads fed meal worms retained water, amounting to about the mass of the meal. 2. secretion of gastric juice in the initial phase of digestion of a large meal would deplete the extracellular fluid of about half of the chloride ions. 3. ingestion and rapid digestion of large meals in toads and other carnivorous vertebrates imply tolerance of large variations in anion composition and acidity of the extracellular fluid. | 1992 | 1347724 |
| effects of arginine vasotocin, cortisol and adrenergic factors on water balance in the toad bufo bufo: physiology or pharmacology? | 1. the threshold level of exogenous arginine vasotocin (avt) for increasing the cutaneous water permeability in bufo bufo was several times higher than has been measured in dehydrated frogs and toads. 2. the beta-agonist isoproterenol was without effect on water balance in hydrated toads but increased the response to large doses of avt by 25-50%. 3. implantation of cortisol pellets in water-acclimated toads enhanced the cutaneous water permeability by a factor of 2-3. 4. it is concluded that und ... | 1992 | 1351446 |
| beta 2-adrenergic regulation of urea permeability of the bufo bufo bladder. | 1. isoprenaline strongly increases the urea permeability of the bladder of bufo bufo. this effect is due to its interaction with beta 2-adrenoreceptors, activating, in turn, the adenyl cyclase. 2. in order to ensure the regulation of urea permeability, the isoprenaline effect is present even in pathophysiological conditions, inhibiting the vasopressin action. | 1992 | 1354117 |
| effect of breeding state, moulting, dehydration, exposure to saturated atmosphere, and arginine vasotocin on cutaneous water permeability in the toad bufo bufo. | cutaneous water permeability was assessed in hydrated male toads under a variety of conditions, including dehydration and rehydration, and the effects of exogenous arginine vasotocin (avt) were determined. cutaneous water permeability (the rate of water uptake by toads in water) was high in toads collected in the breeding pond and declined steeply during the first week, coincident with reduced activity of the cutaneous mucus glands. the slopes of the dose-response curves relating avt to cutaneou ... | 1992 | 1426963 |
| glutathione transferase isoenzymes from bufo bufo embryos at an early developmental stage. | six forms of glutathione transferase (gst) were resolved from the cytosolic fraction of bufo bufo embryos at developmental stage 4 by gsh-sepharose affinity chromatography followed by f.p.l.c. chromatofocusing in the 9-6 ph range. they have apparent isoelectric points at ph 8.37 (gst i), 8.22 (gst ii), 8.10 (gst iii), 7.84 (gst iv), 7.37 (gst v) and 7.12 (gst vi), and each displayed an apparent subunit molecular mass of 23 kda by sds/page. the bufo bufo embryo enzymes showed very similar structu ... | 1992 | 1567369 |
| configurational pattern discrimination responsible for dishabituation in common toads bufo bufo (l.): behavioral tests of the predictions of a neural model. | recently, a neural model of visual pattern discrimination for stimulus-specific habituation was developed, based on previous behavioral studies which demonstrated that toads exhibit a dishabituation hierarchy for different worm-like stimuli. the model suggests that visual objects are represented by temporal coding and predicts that the dishabituation hierarchy changes when the stimulus/background contrast direction is reversed or the stimulus size is varied. the behavioral experiments reported i ... | 1992 | 1593501 |
| experimental population dynamics of rhabdias bufonis (nematoda) in toads (bufo bufo): density-dependence in the primary infection. | density-dependence in worm establishment, numbers, biomass and larval production were examined in primary infections of 0, 10, 40, 80 and 160 larvae of the lung nematode, rhabdias bufonis in the common toad, bufo bufo. the infection procedure established 4 non-overlapping levels of infection which persisted until 6 weeks post-infection (p.i.), after which there was an overall decline up to 12 weeks p.i. worm numbers had no direct effect on adult worm survival but temporal changes in worm weight ... | 1992 | 1614734 |
| ecg and electrodermal response in rana temporaria and bufo bufo under the influence of autonomic-acting drugs. | | 1992 | 1630497 |
| comparison of the capsaicin- and amino acid-sensitivity of dorsal root c fibres in the rat and the toad. | 1. the c elevation of the compound action potential (cap) was recorded with suction electrodes from dorsal roots of rats at 25 degrees c and toads (bufo bufo) at 10 degrees c. the c fibre cap had a conduction velocity of 0.5 +/- 0.07 se m per sec (n = 10) and 0.25 +/- 0.04 m per sec (n = 8) in the rat and toad nerves respectively. 2. the depressant effect of applied drugs on the amplitude of the c fibres cap was measured. nerves from both species had similar sensitivities to gaba. ec50 5.0 micro ... | 1991 | 1685427 |
| water and salt balance at low temperature in a cold temperate zone anuran, the toad bufo bufo. | | 1991 | 1685960 |
| [adaptative differential maturation of neurohypophyseal provasotocin in amphibians: presence of hydrin 2(vasotocinyl-glycine) in anura but not in urodela]. | occurrence of hydrin 2 (vasotocinyl-glycine), an intermediate in the provasotocin processing, has been shown in the neurointermediate lobe of the pituitary of semi-aquatic or terrestrial amphibian species belonging to the order anura, namely rana esculenta, r. temporaria, r. pipiens (ranidae), and bufo bufo, b. marinus, b. ictericus (bufonidae). in contrast hydrin 2 appears absent in species belonging to the order urodela, namely the axolotl ambystoma mexicanum (ambystomidae) and the pleurodele ... | 1991 | 1756409 |
| hematological studies on naturally occurring substances. vi. effects of an animal crude drug "chan su" (bufonis venenum) on blood coagulation, platelet aggregation, fibrinolysis system and cytotoxicity. | during the screening test of the animal crude drug "chan su" (chinese name, toad-cake), the venom of bufo bufo gargorizans cantor (bufonidae), on blood coagulation, platelet aggregation, fibrinolysis system and cytotoxicity, the ethyl acetate extract showed promotive action on platelet aggregation and remarkable cytotoxic activity on hela-s3 cells. nine kinds of bufadienolides were isolated from the ethyl acetate extract by bioactivity-guided fractionation and were identified by chemical and spe ... | 1991 | 1797437 |
| morphological distinction between filaments that converge upon desmosomes and those that are attached to hemidesmosomes in the epidermis of anuran larvae and lampreys. | two populations of morphologically distinct intermediate filaments which are segregated into different compartments of the cytoplasm and which may attach to different junctional specialisations were observed in the basal layer cells of the epidermis of tadpoles of rana catesbeiana, rana temporaria, bufo bufo, leptodactylus flavopictus and pseudis paradoxus and in the skin of the adult lamprey, lampetra planeri. these two distinct populations of cytokeratin intermediate filaments were recognised ... | 1991 | 2050573 |
| radial astrocytes and ependymocytes in the spinal cord of the adult toad (bufo bufo l.). an immunohistochemical and ultrastructural study. | immunohistochemical and ultrastructural techniques have been used to demonstrate glial fibrillary acidic protein (gfap) immuno-positive cells in the adult toad spinal cord. two types of gfap-immunoreactive cells were observed: ependymocytes and radial astrocytes. gfap-positive ependymocytes were scarce and contained the immunoreactive product in their processes. they showed intermediate filaments in the basal pole and in their processes when studied with the electron microscope. these immuno-pos ... | 1990 | 2113429 |
| [a neurophysiological analysis of the forms of wakefulness and rest in the toad bufo bufo and the frog rana ridibunda in the circadian cycle]. | studies have been made on the spectral eeg parameters in the forebrain and midbrain of the toad and frog during active and passive forms of natural behaviour within a diurnal cycle. basing on evaluation of animal reactivity and on eeg analysis performed by presentation of the power of eeg signals via the frequency spectrum, it is possible to obtain a reliable identification of functional condition of amphibians. behavioural and eeg patterns of 3 forms of wakefulness and 2 forms of rest are prese ... | 1990 | 2115707 |
| responses of medullary neurons to moving visual stimuli in the common toad. i. characterization of medial reticular neurons by extracellular recording. | the concept of coded 'command releasing systems' proposes that visually specialized descending tectal (and pretectal) neurons converge on motor pattern generating medullary circuits and release--in goal-specific combination--specific action patterns. extracellular recordings from medullary neurons of the medial reticular formation of the awake immobilized toad in response to moving visual stimuli revealed the following main results. (i) properties of medullary neurons were distinguished by locat ... | 1990 | 2124265 |
| responses of medullary neurons to moving visual stimuli in the common toad. ii. an intracellular recording and cobalt-lysine labeling study. | intracellular recording and labeling of cells from the toad's (bufo bufo spinosus) medulla oblongata in response to moving visual (and tactual) stimuli yield the following results. (i) various response types characterized by extracellular recording in medullary neurons were also identified intracellularly and thus assigned to properties of medullary cell somata. (ii) focussing on monocular small-field and cyclic bursting properties, somata of such neurons were recorded most frequently in the med ... | 1990 | 2124266 |
| changes of a high molecular mass proteinase activity during bufo bufo development. | 1. a chymotrypsin-like proteolytic activity was found both in unfertilized eggs and in embryos of bufo bufo. 2. a dramatical change of activity can be observed in the course of embryonic development. the activity rapidly increases after fertilization up to the stage 9 followed by a fall to a level close to unfertilized eggs. 3. gel chromatography analysis reveals, in all stages of development, the presence of a single peak of proteinase activity characterized by a very high molecular mass. 4. pr ... | 1990 | 2128227 |
| [distribution of 5-hydroxytryptamine immunostaining cells in various tissues of bufo bufo gargarizans]. | the distribution of 5-hydroxytryptamine (5-ht) immunostaining cells in the digestive tracts (hibernation and nonhibernation), the brain and other various tissues of bufo bufo gargarizans was studied by peroxidase anti-peroxidase immunocytochemical method. in the brain, 5-ht immunostaining cells were localized in the raphen nuclear area of brain stem and in the ependyma cell area of the ventriclus tertius of diencephalon. these immunostaining cells were round or oval. the cells usually possess pr ... | 1990 | 2128674 |
| heat capacity and entropy changes of the major isotype of the toad (bufo) parvalbumin induced by calcium binding. | the possible structural changes in the major isotype of parvalbumin from the toad (bufo bufo japonicus) skeletal muscle caused by ca2+ and mg2+ binding have been analyzed by microcalorimetric titrations. parvalbumin was titrated with ca2+ in both the absence and presence of mg2+ and with mg2+ in the absence of ca2+, at ph 7.0, and at 5 degrees, 15 degrees, and 25 degrees c. the two sites in a molecule were equivalent on mg2(+)-ca2+ exchange, but distinguishable on ca2+ and mg2+ binding. the reac ... | 1990 | 2156694 |
| morphogenesis of the frontal organ in bufo bufo during development. | morphogenesis of the frontal organ in bufo bufo was examined under transmission electron microscope. many remarkable similarities to the frontal organ of other amphibia anura are observed. it originates from a diverticulum in the dorsal region of the neural tube. it is egg-shaped, has an eccentric lumen, and is made up of three kinds of cells: 1) photoreceptors, which protrude into the lumen; 2) supportive cells; and 3) ganglion cells, which make synaptic contact with the photoreceptors. peculia ... | 1990 | 2350014 |
| effect of vasopressin on the permeability of non electrolytes across the skins of rana esculenta and bufo bufo. | maximal doses of vasopressin increase the permeability of the skins of bufo bufo and rana esculenta to urea, ethylene glycol, glycerol, erythritol, beta-alanine, leaving virtually unmodified that of mannitol and antipyrine. these results demonstrate that the response to vasopressin is quite different in amphibian skins as compared to the bladders. a careful analysis of the effects of vasopressin on non-electrolyte permeability as a function of their molecular weight demonstrates that hormone eli ... | 1985 | 2412508 |
| genesis and regression of the figures of eberth and occurrence of cytokeratin aggregates in the epidermis of anuran larvae. | in tadpoles of rana temporaria, bufo bufo and xenopus laevis the development of the massive skeins of tonofilaments (cytokeratin intermediate filaments) that form the figures of eberth follows a similar sequence in all species studied. increase in the number of filaments is preceded by increase in polyribosomes and rer in the basal layer cells of the epidermis. a filamentous zone develops proximally in the cells concurrently with hemidesmosomes, which assume the typical larval bobbin form as the ... | 1986 | 2422986 |
| neuroglia of the optic tectum in the bufo bufo (amphibian anura), first trials. | only one predominant type of glial cell can be recognized in the bufo bufo toad's optic tectum, obtained sagitally cut in 40 microns thick sections and stained with sublimate-gold cajal's method. this basically elementary cell type is represented by ependymal gliocytes (horstmann's tanycytes) with long processes in small parallel bundles disposed radially, extending from the ventricular surface to the sub-pial surface forming terminal end-feet thickenings. these processes can lose themselves fre ... | 1987 | 2442243 |
| diverse supernumerary structures develop after inverting the anteroposterior limb axis of the anuran. | contralateral limb bud graftings were performed on tadpoles of the anuran bufo bufo. the anteroposterior axis was inverted while the larvae were at stage iv or v (e.g., between 22-30 days after fertilization). eighty-four tadpoles were operated on, 10 of which were used as controls. at anterior or posterior location 104 supernumerary structures developed in toto. they were collected and whole-mount examined after being stained with alcian blue. they were further prepared for serial sectioning, m ... | 1989 | 2466718 |