| spermatogonial responsiveness to mammalian gonadotropins in subadult rana nigromaculata. | | 1978 | 620917 |
| [separation of agglutinin from eggs of rana nigromaculata nigromaculata hallowell and its interaction with ascites hepatoma (author's transl)]. | | 1975 | 166153 |
| correlative light and electron microscopy of the frog adrenal gland cells using adjacent epon-embedded sections. | correlative light and electron microscopy on the same cells of the adrenal gland of the frog, rana nigromaculata, fixed in glutaraldehyde followed by osmium tetroxide, was done using the adjacent epon embedded sections. electron microscope observation revealed three different types of granule-filled secretory cells; the noradrenaline-storing cells (na cells) filled with intensely dense and varying shaped granules, the adrenaline-strong cells (a cells) filled with relatively less dense granules a ... | 1976 | 61744 |
| fine structural distribution of the surface-connected canalicular system in frog thrombocytes. | the existence of the surface-connected canalicular system (sccs) has been demonstrated in semithick sections of the frog thrombocytes by the use of a high voltage electron microscope. the sccs of the thrombocytes in rana catesbeiana and rana nigromaculata consists of numerous canaliculi and vesicles with a diameter of 250 nm, which join with one another to make a complex network throughout the cytoplasm. although the sccs of xenopus laevis fits well into the pattern described in rana catebeiana, ... | 1979 | 315820 |
| characterization of the constituent fatty acids in phosphatidylinositol during early development in rana nigromaculata. | 1. qualitative and quantitative changes in phosphatidylinositol (pi) were analyzed in the eggs, embryos and tadpoles of the japanese pond frog, rana nigromaculata, at various stages of development. 2. the weight percentage of pi to total phospholipid and lipid was about 8.4-15.2% and 1.4-2.6%, respectively, during embryonic life. 3. at the early stages of the unfertilized egg and the two-cell embryo, the predominant fatty acids are palmitic, stearic, oleic and linoleic acid. from the dorsal lip, ... | 1988 | 3396317 |
| microiontophoresis and single-unit analysis of cholinergic drugs in the optic tectum of frog. | microiontophoresis of acetylcholine (ach), atropine, or curare was accompanied by single-unit analysis of visual neuronal responses in the optic tectum of rana nigromaculata. in 71% of the units tested, ach enhanced responses to visual stimuli, while atropine suppressed visual responses. twenty-two percent of the remainder showed no ach- or atrophin-induced effects and were recorded within 125 microns of the pial surface. the majority of ach-enhanced, atropine-suppressed units were recorded from ... | 1986 | 3567546 |
| high-resolution scanning electron-microscopic studies on the three-dimensional structure of mitochondria and sarcoplasmic reticulum in the different twitch muscle fibers of the frog. | the three-dimensional structure of the mitochondria and sarcoplasmic reticulum (sr) in the three types of twitch fibers, i.e., the red, white and intermediate skeletal muscle fibers, of the vastus lateralis muscle of the japanese meadow frog (rana nigromaculata nigromaculata hallowell) was examined by high resolution scanning electron microscopy, after removal of the cytoplasmic matrices. the small red fibers have numerous mitochondrial columns of large diameter, while the large white fibers hav ... | 1987 | 3690630 |
| the ultrastructure of the teeth in the amphibian: differentiation of the dentine of hyla japonica and rana nigromaculata nigromaculata. | | 1986 | 3467259 |
| [the effects of carbamylation of hormones on their biological activities--with reference to 3,5,3'-l-triiodothyronine and insulin]. | it has been demonstrated that the binding of cyanic acid, formed from urea which is increased in renal failure, to hemoglobin (hb) results in the formation of hba1. the combination of hb and cyanic acid is called carbamylation, a nonspecific reaction between protein and cyanic acid. it is theoretically considered that like glycation, carbamylation may occur between cyanic acid and not only hb but also various peptides and proteins. in the present study, hormones were subjected to carbamylation, ... | 1987 | 3301423 |
| [three-dimensional architecture of the oral mucous epithelium of the frog (rana nigromaculata)]. | | 1988 | 3255650 |
| failure of sex hormones and pms to stimulate gonadal development in young rana nigromaculata. | | 1974 | 4829479 |
| scanning electron-microscopic study on the three-dimensional structure of motor endplates of the slow (tonic) muscle fibers in the frog, rana n. nigromaculata. | the three-dimensional organization of the motor endplates of the slow fibers of the rectus abdominis muscle in the japanese meadow frog (rana nigromaculata nigromaculata hallowell) is visualized by use of a field-emission scanning electron microscope after removal of connective tissue components by hcl hydrolysis. clusters of shallow oval depressions approximately 1-3 microns in diameter are seen in the postsynaptic membrane at intervals of about 150 microns. on the surface of these depressions, ... | 1988 | 3378261 |
| high resolution scanning electron-microscopic study on the three-dimensional structure of the sarcoplasmic reticulum in the slow (tonic) muscle fibers of the frog, rana nigromaculata. | the three-dimensional structure of the sarcoplasmic reticulum (sr) in the slow (tonic) fibers of the rectus abdominis muscle of the japanese meadow frog (rana nigromaculata nigromaculata hallowell) was examined by high resolution scanning electron microscopy, after removal of the cytoplasmic matrices by the osmium-dmso-osmium procedure. the sr forms a repetitive network throughout these fibers. at the level of the z-line, a slender transverse tubule (t-tubule) runs transversely to the longitudin ... | 1989 | 2706668 |
| [surface architecture of the stratified squamous epithelium of the amphibian (rana nigromaculata): comparison with mammalian oral epithelial cells]. | | 1988 | 3255651 |
| comparative studies on the vascular organization of carotid labyrinths of anurans and caudates. | the three-dimensional structures of the carotid labyrinth in five species of anurans representing four families (rana nigromaculata, rana catesbeiana, bufo japonicus, hyla arborea, and xenopus laevis), and three species of caudates representing three families (cynops pyrrhogaster, hynobius nebulosus, ambystoma mexicanum) were compared using vascular corrosion castings and scanning electron microscopy (sem). anuran carotid labyrinths are spherical in shape and are classified into two groups accor ... | 1990 | 2338718 |
| the effect of catecholamines on the pars intermedia autotransplanted into the anterior chamber of the eye of the frog, rana nigromaculata. | | 1974 | 4449590 |
| fine structure and functional properties of the thyroid of the anura, rana nigromaculata nigromaculata (a part of the phylogenetic studies of the thyroid gland). | | 1970 | 5465076 |
| proliferation of primordial germ cells of frogs stimulated by a fraction of granules derived from rana nigromaculata embryos at the tail-bud stage. | a fraction of heavy granules, obtained from embryos of the frog (rana nigromaculata) at the tail-bud stage by centrifugation at 1700 x g, were shown to stimulate the formation of proliferation of the primordial germ cells not only of the same species but also of a closely related species. | 1989 | 2599061 |
| [chronological observation of intestinal lesions of rats experimentally infected with echinostoma hortense]. | intestinal histopathological changes due to infection with echinostoma hortense (trematoda) were studied in rats after experimental infection with the metacercariae. the metacercariae were obtained from the tadpoles of rana nigromaculata, a second intermediate host infected in the laboratory. total 18 albino rats (sprague-dawley) were given 200 matacercariae each and sacrificed on the day 1, 3, 7, 11, 22 or 44 post-infection (pi). segments of the small intestine at 1, 3, 5, 8 and 30 cm posterior ... | 1990 | 2271500 |
| gonadotropin-induced luminal formation in the seminiferous tubules and efferent ductules in young frogs: light and electron microscopic study. | to clarify the mechanism of fluid secretion in the testes at the time of gonadotropin-induced spermiation, young rana nigromaculata were used. as a morphological index of fluid secretion, luminal formation of the seminiferous tubules, and efferent ductules were observed. the following changes were seen by the administration of hcg or frog pituitary: first, the luminal formation of the seminiferous tubules was seen; next, tubular expansion became evident, and finally, luminal formation and expans ... | 1989 | 2607329 |
| on the third peptide active on smooth muscle in the skin of rana nigromaculata hallowell. | | 1968 | 5751736 |
| experimental life history of spirometra erinacei. | the complete life cycle of spirometra erinacei has been experimentally maintained in the laboratory. the cyclops were reared as the first intermediate host, and the tadpoles of rana nigromaculata as the second intermediate host. icr mice were used as another second host. the experimental definitive hosts were dogs and cats. maturation and hatching of the eggs took 8 to 14 days by incubation at 29 degrees c. the coracidium measured 43.8 x 36.9 microns. mesocyclops leuckarti and eucyclops serrulat ... | 1990 | 2095198 |
| relationship between lectin-affinity granules in anuran embryos and formation of primordial germ cells. | embryos of the anuran, rana nigromaculata, contained granules with a specific affinity for con a and gs-i. larvae derived from embryos injected with these lectins had a noticeable reduction in both the number and size of primordial germ cells (pgcs). this observation suggests that the granules are somehow involved in the formation of pgcs. | 1991 | 1999253 |
| colloid-like droplets in the pars intermedia of the frog rana nigromaculata. | | 1967 | 5634154 |
| study of amphibian lipids. i. characterization of monoglycosylceramides from the skin of rana nigromaculata (japanese pond frog). | 1. monoglycosylceramide was isolated from the skin of rana nigromaculata (japanese pond frog), and further fractionated into three subgroups (fraction i, fraction ii and fraction iii) by borate-impregnated florisil column chromatography. 2. fraction i and fraction ii contained mainly glucose as their hexose components, while fraction iii contained galactose. 3. major long chain bases of fraction i and fraction iii were d-erythro-1, 3-dihydroxy-2-amino-4-trans-octadecene (4-sphingenine) and d-ery ... | 1975 | 1182140 |
| cloning and sequencing of the cdna encoding tyrosinase of the japanese pond frog, rana nigromaculata. | we cloned and sequenced the cdna encoding tyrosinase (tyn) of the japanese pond frog, rana nigromaculata. the 3511-bp cdna contained a 54-bp 5'-noncoding region, a 1596-bp open reading frame encoding tyn of 532 amino acids (aa), and a 1861-bp 3'-noncoding region. the aa sequence of frog tyn predicted from the cdna sequence was homologous to that of mouse and human tyns. the aa sequence including the copper-binding domain, which is likely the active center of tyn, was highly conserved among these ... | 1992 | 1446833 |
| trematodes of the genus haematoloechus (digenea: plagiorchiidae) from frogs in korea. | total 242 rana nigromaculata and 9 r. catesbeiana were collected from the various localities in korea from february 1989 to july 1991, and their lungs were examined. five species in genus haematoloechus, i.e., h. sibiricus japonicus (yamaguti, 1936), h. nanchangensis hsiung, 1934, h. variegatus (rudolphi, 1819), h. lobatus (seno, 1907), h. lobatus koreanus, were identified in this study. among them, h. lobatus koreanus was a new subspecies and h. variegatus and h. lobatus were newly recorded fro ... | 1992 | 1297413 |
| comparative studies on the electric nature of amphibian gonadotropin. | the isoelectric focusing (ief) profiles of pituitary gonadotropic (gth) activity in six species of adult male amphibians were examined in addition to the newt and bullfrog. the gth activity was measured by two radioreceptor assay (rra) systems; one with xenopus laevis testicular homogenate as the receptor preparation, and the other with anolis carolinensis testicular homogenate, both employing 125i-labeled rat fsh as the radioligand, or by a radioimmunoassay (ria) system for bullfrog basic gth ( ... | 1985 | 3874809 |
| [experimental life history of echinostoma hortense]. | the complete life cycle of echinostoma hortense has been maintained in the laboratory, using lymnaea pervia snails and rana nigromaculata tadpoles as the first and second intermediate hosts. icr mice was used as the definitive host. within the egg of e. hortense, the miracidium was fully matured in 13 days of incubation at 29-30 degrees c. the miracidium was 93.8 x 53.6 microns in average size, covered with numerous cilia of 7-11 microns length. the epidermal plates were arranged in 6-8-4-2 form ... | 1991 | 1954199 |
| an experimental study demonstrating the physiological polarity of the frog's utricle. | the frog rana nigromaculata was used as an experimental model. the utricle and its nerve were isolated with the anterior and the lateral semicircular canal ampullae in frog ringer's solution. the utricular otoconia and the otoconial membrane were then carefully removed. the halved anterior canal cupula was next placed in the tip of a glass microelectrode, which was mounted on a micromanipulator. the cupula was placed in the center of either the medial or the lateral part of the macula and was mo ... | 1987 | 3689199 |
| the demonstration of the spindle fiber attachments in the amphibian liver and sperm nuclei by the sera from scleroderma patients. | the isolated liver nuclei and the mature sperm nuclei from rana nigromaculata and bufo bufo asiaticus had been investigated by indirect immunofluorescence method with anti serum specific to the spindle fiber attachments (sfas) from the scleroderma patients with crest syndrome. it was found that in the isolated liver nuclei and the mature sperm nuclei of these animals there are discrete speckles which bind the antibody specific to the sfas. the maximum number of these speckles counted in a single ... | 1985 | 3879774 |
| [the development of the musculature of the abdominal wall in anura, rana nigromaculata, and in some vertebrates]. | | 1966 | 4224572 |
| secretory activity of the intraocular homotransplanted pars intermedia of the frog, rana nigromaculata. | to examine whether there is a possible inhibitory effect of melanophore-stimulating hormone (msh) on the release of msh from the pars intermedia, two groups of frogs, rana nigromaculata, were prepared with median eminence extirpation to eliminate the inhibitory hypothalamic control over msh secretion. in one of the two groups, the animal's own intermediate lobe was transplanted to the anterior chamber of the eye (intraocular autotransplanted gland), and in the second, the animal's own pars inter ... | 1986 | 3762865 |
| [structural differences in the collagens of rana frog species with dissimilar temperature ecology. the contribution of carbohydrate components to collagen molecular thermostability]. | skin procollagens in two species groups of frogs of the genus rana - brown frogs (4 species) and green frogs (3 species) distributed in european and asiatic parts of the ussr have been compared. a geographic intraspecific variation in collagen characteristics (two geographic populations of the pond frog rana nigromaculata) is revealed. intergroup differences in the thermal denaturation of collagens established by means of methods of circular dichroism and microcalorimetry are significant. such d ... | 1982 | 6980509 |
| cardiotonic activities of 3,5-seco-4-nor-cardenolides in rana nigromaculata. | | 1975 | 1157868 |
| [seasonal changes in hemagglutination inhibition substance of japanese encephalitis virus in rana nigromaculata nigromaculata]. | | 1970 | 4319798 |
| studies on muscle differentiation. i. isolation and purification of structural proteins from leg muscles of the frog, rana nigromaculata. | | 1970 | 4249577 |
| changes in skin color and fine structure of the intermediate pituitary gland of the frog, rana nigromaculata, after extirpation of the median eminence. | | 1971 | 5093954 |
| [the effect of fractionated x-rays and gamma-rays irradiation on tadpole of amphibia. (i). rana nigromaculata]. | | 1966 | 5232003 |
| the effect of 2,3-dimercaptopropanol on the melanocyte of rana nigromaculata. | | 1967 | 5004776 |
| [effects of 2,3-dimercaptopropanol on skin serotonin level and melanocyte dispersion in rana nigromaculata]. | | 1970 | 5464138 |
| occurrence of a new active peptides in smooth muscle and bradykinin in the skin of rana nigromaculata hallowell. | | 1968 | 5677638 |
| hepatic melanosis and ageing in amphibia. a preliminary observation on two species of anura xenopus laevis and rana nigromaculata. | | 1974 | 4442478 |
| the response of frog taste cells (rana nigromaculata and rana catesbeana). | | 1969 | 5801788 |
| effects of testosterone and estradiol on the development of sexual characters in young rana nigromaculata. | | 1974 | 4457144 |
| the melanophore-stimulating potency of the pituitary gland of the black background-adapted rana nigromaculata after administration of 2,3-dimercaptopropanol. | | 1968 | 5715130 |
| retinotopic analysis of fiber pathways in amphibians. ii. the frog rana nigromaculata. | the possibility of retinotopic organization of pathways of retinal fibers within the optic tract and the tectum of the frog was studied by selective labeling of the retinal fibers with horseradish peroxidase. within the optic tract the pathways of the ventral, temporal and dorsal retinal fibers were ordered from the dorsal to ventral edges of the optic tract. the nasal retinal fibers ran along both the dorsal and ventral edges of the optic tract. the dorsal retinal fibers and the nasal retinal f ... | 1981 | 6162520 |
| [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 |
| positional distribution of constituent fatty acids in phosphatidylethanolamine during early development in rana nigromaculata. | qualitative and quantitative changes in phosphatidylethanolamine (pe) were analyzed in the eggs, embryos and tadpoles of the japanese pond frog, rana nigromaculata, at various stages of development. the weight percentage of pe to total phospholipid and to total lipid was about 15-18% and about 3-4%, respectively, during embryonic life. at all stages from the unfertilized egg to the feeding tadpole, the major fatty acids at the 1-position of pe were palmitic, stearic and oleic acids. at the 2-pos ... | 1986 | 3757478 |
| evaluation of in vitro melanocyte-darkening activities of l-histidyl-l-phenylalanyl-l-arginyl-l-tryptophyl-glycine and its nine stereoisomers in rana nigromaculata. | | 1966 | 5298304 |
| a kinetic analysis of the facilitatory action of adrenaline. | the 22na+-efflux from skeletal muscle cells of frog (rana nigromaculata) was measured in ringer solutions containing different concentrations of k+ (0.1 to 30 mm). the effects of adrenaline (30 microm) and ouabain (10 microm) on the 22na+-efflux were investigated for the purpose to clarify the mechanism of the facilitatory effect of adrenaline on na+ - k+ pump. the rate coefficient for the ouabain-sensitive 22 na+-efflux increases with increasing extracellular k+ concentrations and adrenaline po ... | 1982 | 7070962 |
| the effect of various conditions on the melanophore-stimulating hormone content of the pituitary gland of rana nigromaculata. | | 1965 | 5870020 |
| [preparation of the isolated retina of rana nigromaculata and determination of the photosensitivity of rhodopsin in situ]. | | 1986 | 3775398 |
| effect of heterospecific dna on the development of rana nigromaculata. | both the dna of a balancer-bearing species (cynops orientalis) and that of a non-balancer-bearing species (rana nigromaculata), when injected into the fertilized eggs of r. nigromaculata, cause some tadpoles derived from the injected eggs to bear a single balancer-like process on the left operculum. based upon these results, it may be so concluded that the occurrence of the balancer-like process in the tadpole is neither due to genetic transformation, nor due to balancer induction, but rather du ... | 1981 | 7256250 |
| [purification, characterization and antitumor activity of rana nigromaculata lectin (author's transl)]. | | 1980 | 7193723 |
| visual field topography in the frog's nucleus isthmi. | responses to visual stimulation were extracellularly recorded with micropipettes from 125 neurons of the left nucleus isthmi in frogs, rana nigromaculata, and 101 electrode tip positions were marked with cobalt staining. the present study indicates that: (1) the entire contralateral hemifield and the nasal 40 degree of the ipsilateral hemifield project on the nucleus isthmi topographically, and (2) there exist binocular units in this nucleus. | 1981 | 7231814 |
| spontaneous larval gnathostoma nipponicum infection in frogs. | from june 1993 to september 1997, a survey was carried out for the prevalence of larval gnathostoma nipponicum infection in several kinds of frogs, toads, and their tadpoles collected from an endemic area of this nematode in aomori prefecture. two frog species, one of 436 (0.2%) rana nigromaculata and 51 of 147 (34.7%) r. catesbeiana were infected, and a total of 446 advanced third-stage larvae (adl3) of g. nipponicum were recovered. these results confirmed that two frog species which can serve ... | 1998 | 9795906 |
| structural changes in gonadotropin-producing cells of male frogs, rana nigromaculata, in the process of sexual maturation. | | 1982 | 7106545 |
| d2-like dopamine receptor mediates dopaminergic or gamma-aminobutyric acidergic inhibition of melanotropin-releasing hormone release from the pars intermedia in frogs (rana nigromaculata). | frogs can adapt to their background by making their skin color lighter or darker as necessary, and this adaptation is regulated by msh. we investigated the mechanism inhibiting msh release from the pars intermedia (pi) of the pituitary gland in frogs (rana nigromaculata) by ultrastructural immunohistochemistry and bioassay using the melanophore index. the pi contained fibers immunoreactive for tyrosine hydroxylase, gamma-aminobutyric acid (gaba), and neuropeptide y, which made synaptic contacts ... | 1995 | 7588269 |
| the amount of melanophore-stimulating hormone in the pars intermedia of single pituitary glands of rana nigromaculata after intraocular homotransplantation of the pars intermedia. | | 1981 | 7349292 |
| frequent development of pancreatic carcinomas in the rana nigromaculata group. | in 1979, 2 species of pond frogs (rana nigromaculata and rana plancyi plancyi) were imported from china, and hybrids were made between these and japanese, korean, and taiwanese pond frogs (r. nigromaculata, rana plancyi fukienensis and rana brevipoda) that had been kept for a number of years in the laboratory for amphibian biology of hiroshima university. from 1982, development of tumors, especially in the peritoneal cavity, was noticed frequently in the hybrids and also later, although rarely, ... | 1995 | 7641193 |
| identification of protein c in sera of the frogs, rana nigromaculata and rana brevipoda. | when sera from the frogs, rana (r.) nigromaculata and rana (r.) brevipoda, were run on starch-gel electrophoresis (sge), several bands were seen in an electrophoretic pattern of proteins. this pattern on sge appeared the same at stages xiv, xv and xxi, and in the adult frog, r. niguromaculata. however, the pattern at stage x was different. a protein, designated "protein c", did not appear clearly at this stage, but afterwards. this protein was the second richest among serum proteins of mature fr ... | 1994 | 7765860 |
| visual field topography and binocular responses in frog's nucleus isthmi. | visual responses of 125 units have been extracellularly recorded with glass micropipettes from the left nucleus isthmi in the frog rana nigromaculata, and 101 electrode tip positions marked with cobalt staining to reconstruct a visual field map in the nucleus. 80% of the units recorded show on-off responses to a stationary spot of light and many are directionally selective in response to black or white targets moving through their receptive fields. all the cobalt-marked spots are within the nucl ... | 1981 | 7302559 |
| eeg activities during kindling in frog. | the "kindling" phenomenon was investigated in relation to the eeg activities in frog, rana nigromaculata. repetitive electrical stimulation to the unilateral hippocampus produced the following results: (1) prolongation in duration of after-discharges (ad) and shortening of ad intervals; (2) appearance and enhancing of spontaneous epileptiform discharges (seds), which were suppressed by isolation of hippocampus; (3) increase in power and duration of background eeg with a specific frequency (9 hz ... | 1980 | 7390708 |
| [seasonal changes of lactate dehydrogenase isozymes and blood glucose concentration in nyctus noctula and rana nigromaculata]. | the blood sugar concentration and the lactate dehydrogenase (ldh) isozymes in serum, brain and skeletal muscle of nyctus noctula during hibernation and of rana nigromaculata during dormancy and activity period were compared by using method of polyacrylanide gel electrophoresis. both ldh isozymes and blood glucose concentration showed obvious seasonal changes. in contrast to animals during activity period, animals in hibernation and dormancy period lacked ldh1, while ldh5 and blood glucose concen ... | 1994 | 7973814 |
| peroxisomal enzyme activity changes in the tail of anuran tadpoles during metamorphosis. | this study attempts to clarify peroxisomal enzyme activity changes in the atrophying tail of anuran tadpoles. changes in catalase, d-amino acid oxidase and urate oxidase activity were spectrophotometrically investigated using tadpole tails of rana japonica and rana nigromaculata. in r. japonica, total catalase activity decreased in tails undergoing regression during spontaneous and dl-thyroxine (t4)-induced metamorphosis, whereas total d-amino acid oxidase and urate oxidase activity increased. i ... | 1995 | 7613770 |
| relative roles of theca and granulosa cells in ovarian follicular steroidogenesis in the amphibian, rana nigromaculata. | using frog ovarian follicles in vitro we assessed the role of the theca/epithelium (thep) layer and granulosa cells in the production of steroids. the thep layer and granulosa cell-enclosed oocytes (gceos) were separated from ovarian follicles of the frog, rana nigromaculata, by microdissection. intact follicles (ifs), thep layer, or gceos were cultured for 6 hr in amphibian ringer's in the presence or absence of various steroid precursors (100 ng/ml) or of frog pituitary homogenate (fph, 0.05 g ... | 1994 | 7926630 |
| motion sickness in amphibians. | we explored the question of whether amphibians get motion sickness by exposing anurans (frogs) and urodeles (salamanders) to the provocative stimulus of parabolic aircraft flight. animals were fed before flight, and the presence of vomitus in their containers after flight was used to indicate motion-induced emesis. none of the species that we studied vomited during the 8 to 10 parabolas of each flight. however, at least one specimen from each of the anuran species rana rugosa, rana nigromaculata ... | 1993 | 8216158 |
| constructions of gene libraries of rana nigromaculata and mus musculus with cosmid phc79. | gene libraries of rana nigromaculata and mus musculus (c57j6) have been constructed by the cosmid system developed by collins using bamhl and pstl as cloning restriction enzymes. a simplified formula, which is a modification of clarke and carbon derived from approximation, was used for calculating the number of colonies or recombinants necessary for the construction of a gene library. pro+ and leu+ complementary to the recipient cells (hb101) with the genetic constitution of pro- and leu- have b ... | 1982 | 6285464 |
| the metabolism of biogenic monoamines during embryogenesis and metamorphosis in two anuran species. | this study investigated the pathways to many monoamines and their metabolites in the central nervous system of the frog rana nigromaculata and the toad bufo bufo japonicus during embryonic development and metamorphosis. metabolites were analyzed by three-dimensional hplc. the two species provided evidence of similar pathways, with slightly different timetables for the development of their monoamine systems. during embryonic development, the main metabolic pathways in entire embryos were tyrosine ... | 1997 | 9204370 |
| changes in the activities of steroidogenic enzymes during the development of ovarian follicles in rana nigromaculata. | earlier studies showed that the predominant steroid (estradiol [e2], testosterone [t], progesterone [p4]) secreted by in vitro cultured amphibian (rana nigromaculata) ovarian follicles varied with their size. e2 was mainly produced by medium-sized follicles, t by intermediate-sized follicles, and p4 by the largest follicles. experiments were carried out to ascertain whether the activities of steroidogenic enzymes changed during follicle development and were responsive to gonadotropic stimulation ... | 1993 | 8282172 |
| 17 alpha,20 alpha-dihydroxy-4-pregnen-3-one is the naturally occurring spermiation-inducing hormone in the testis of a frog, rana nigromaculata. | spermiation, the process in which vertebrate spermatozoa are detached from investing sertoli cells into the lumen of the seminiferous tubule, is a prerequisite for the successful fertilization. using an in vitro rana nigromaculata spermiation bioassay, we have shown that gonadotropin initiates spermiation by inducing the synthesis of delta 4-steroids by testis fragments. among all of the delta 4-steroid metabolites produced by r. nigromaculata testis fragments, spermiation-inducing activity was ... | 1993 | 8319579 |
| microsomal monooxygenase system in frog livers. | liver microsomes prepared from four species of frog, rana catesbeiana, rana nigromaculata , bufo bufo japonicus, and xenopus laevis, contained cytochrome p-450 and showed nad(p)h-dependent monooxygenase activities to several foreign chemical compounds tested. the oxidations of the chemical compounds by frog liver microsomes showed significant variations among frog species. the oxidation of 7-ethoxycoumarin was much faster than that by rat liver microsomes. the oxidation of benzo(a)pyrene was sig ... | 1984 | 6329594 |
| amphidiploidy recovers the viability of hybrids of european and east asian water frogs. | reciprocal diploid hybrids, artificially produced from crosses between rana nigromaculata and rana lessonae, die at the stage from neurula to tailbud. we found in a previous study that triploid hybrids having two r. nigromaculata genomes and one r. lessonae genome in r. nigromaculata cytoplasm grow into mature frogs, whereas triploid hybrids composed of the other combinations of genome and cytoplasm arrest before hatching. in this study, we made amphidiploid hybrids with two r. nigromaculata and ... | 1997 | 9293636 |
| planorbid snails as potential molluscan intermediate host of a human intestinal fluke, neodiplostomum seoulensis (trematoda : diplostomatidae) in korea. | three species of the pulmonate snails of the family planorbidae have been reported from korea; gyraulus convexiusculus, hippeutis (helicorbis) cantori and segmentina (polypylis) hemisphaerula. of these 3 species, only h. cantori is reported as the molluscan intermediate host of neodiplostomum seoulensis, one of the important snail-borne human intestinal trematodes in korea. however, s. hemisphaerula was also found to be an intermediate host for n. seoulensis. in field-collected snails, h. cantor ... | 1997 | 9656378 |
| stero-bile acids and bile alcohols. lxxv. studies on bile of rana nigromaculata. | | 1965 | 5861329 |
| seasonal fluctuations in pituitary gland and plasma levels of gonadotropic hormones in rana. | changes in plasma and pituitary levels of two gonadotropins, luteinizing hormone (lh) and follicle-stimulating hormone (fsh), in male and female korean frogs (rana dybowskii and rana nigromaculata) were examined. plasma levels of lh and fsh were measured by radioimmunoassay using antibodies raised against bullfrog lh and fsh. in male and female r. dybowskii, plasma concentrations of lh were low in early hibernation (october-january) and increased to high levels by late hibernation, when breeding ... | 1998 | 9446718 |
| possible role of serotonin in merkel-like basal cells of the taste buds of the frog, rana nigromaculata. | merkel-like basal cells in the taste buds of the frog were examined by fluorescence histochemistry, immunohistochemistry and electron microscopy. there were about 16-20 basal cells arranged in a radial fashion at the base of each taste bud. these cells were strongly immunopositive for serotonin antiserum. they were characterised by the presence of numerous dense-cored granules in the cytoplasm ranging from 80 to 120 nm in diameter, and of microvilli protruding from the cell surface. for 4 mo aft ... | 1998 | 10029193 |
| [fluorescent substances of the pterin type in the skin or the eyes of the frog (rana nigromaculata) and their photochemical transformation]. | | 1953 | 13095436 |
| comparison of xenopus laevis and rana nigromaculata as test animals for the determination of pregnancy. | | 1953 | 13096903 |
| evolutionary relationships among japanese pond frogs inferred from mitochondrial dna sequences of cytochrome b and 12s ribosomal rna genes. | the evolutionary relationships among japanese pond frogs (rana nigromaculata, r.porosa porosa, and r. p. brevipoda) were investigated by analyzing nucleotide sequences of mitochondrial cytochrome b (cyt b) and 12s rrna genes. the nucleotide sequences of 444-bp segment of the cyt b gene and 410-bp segment of 12s rrna gene were determined by the pcr-direct sequencing method using 18 frogs from 13 populations of japanese pond frogs, and phylogenetic trees were constructed by the neighbor-joining an ... | 1998 | 9718677 |
| pregnenolone, pregnenolone sulfate, and cytochrome p450 side-chain cleavage enzyme in the amphibian brain and their seasonal changes. | to clarify whether the amphibian brain synthesizes de novo neurosteroids, we examined pregnenolone, pregnenolone sulfate ester, and cytochrome p450 side-chain cleavage enzyme (cytochrome p450scc), an enzyme converting cholesterol to pregnenolone, using amphibians. pregnenolone and its sulfate ester in the brain, gonad, and plasma of xenopus laevis were measured by a specific pregnenolone ria. the concentrations of these two steroids in the female brain were significantly larger than those in the ... | 1999 | 10098534 |
| diversity of opsin immunoreactivities in the extraretinal tissues of four anuran amphibians. | the pineal complex, deep brain, and skin have been known to function as extraretinal photoreceptors in non-mammalian vertebrates. to see the diversity of localization of extraretinal photoreceptors in lower vertebrates having different habitats, we analyzed the opsin-like immunoreactivities in anuran amphibians, xenopus laevis, rana catesbeiana, rana nigromaculata, and bufo japonicus. an antiserum (toad rh-as) was raised against rhodopsin purified from the retinas of japanese toad, b. japonicus. ... | 2000 | 10617855 |
| comparison of the morphology of the inner ear between newts and frogs in relation to their locomotory capability. | the ultrastructural differences between the inner ears of japanese red-bellied newts (cynops pyrrhogaster) and black-spotted pond frogs (rana nigromaculata) were investigated. scanning electron microscopic observations showed apparent morphological differences in the shape of the ampulla cristae and the localization of the striola in the saccular macula. there were differences in the length of the kinocilia of the sensory hairs in each sensory region. in addition, the diameters of the bundles of ... | 2002 | 12130811 |
| structural study of novel antimicrobial peptides, nigrocins, isolated from rana nigromaculata. | novel cationic antimicrobial peptides, named nigrocin 1 and 2, were isolated from the skin of rana nigromaculata and their amino acid sequences were determined. these peptides manifested a broad spectrum of antimicrobial activity against various microorganisms with different specificity. by primary structural analysis, it was revealed that nigrocin 1 has high sequence homology with brevinin 2 but nigrocin 2 has low sequence homology with any other known antimicrobial peptides. to investigate the ... | 2001 | 11682065 |
| segmentina hemisphaerula: a new molluscan intermediate host for echinostoma cinetorchis in korea. | three species of planorbidae have been reported from korea, e.g., gyraulus convexiusculus, hippeutis (helicorbis) cantori, and segmentina (polypylis) hemisphaerula. of these, only h. cantori was reported as the first and second intermediate host for echinostoma cinetorchis, an important human intestinal parasite in korea. segmentina hemisphaerula has also been found to be an intermediate host. in field-collected planorbids, only s. hemisphaerula was found shedding echinostome cercariae and infec ... | 2001 | 11695387 |
| the life cycle and larval development of fibricola seoulensis (trematoda: diplostomatidae). | the life cycle of fibricola seoulensis was studied in the laboratory and in the field, with special interests in the larval developments within the eggs and in the intermediate hosts. the first emergence of miracidia after incubation of eggs in 26c water began on the ninth day. the miracidia, elongate and cylindrical shape, had epidermal plates in the formula of 6, 9, 4 and 3, with two pairs of flame cells and lateral processes. a kind of fresh water snail, hippeutis (h.) cantori, was found to s ... | 1988 | 12811046 |
| developmental capacity and chromosome number in the offspring of artificially produced autotetraploids of rana nigromaculata. | a large number of autotetraploids of rana nigromaculata were produced in order to assess their developmental capacity and chromosome number in their offspring. an original autotetraploid male was first produced by transplanting a nucleus from an embryo (triploid) into an unfertilized egg. next, eggs were inseminated with sperm of the autotetraploid male, then cold-treated to obtain first-, second-, and third-generation offspring. according to an investigation of the chromosome numbers of the tad ... | 2002 | 12193803 |
| expression and localization of cytochrome p450(11beta,aldo) mrna in the frog brain. | the present study is focused on biosynthesis of adrenal steroids in the frog brain. employing rt-pcr method using total rna from the adult rana nigromaculata brain, we isolated a 419-bp fragment of cdna encoding cytochrome p450(11beta,aldo), which catalyzes the final step of biosynthesis of the frog adrenal steroids, corticosterone and aldosterone. the deduced amino acid sequence of r. nigromaculata brain cytochrome p450(11beta,aldo) shared a high homology (88.8%) with that of r. catesbeiana adr ... | 2002 | 12231255 |
| mechanism of chromosome elimination in the hybridogenetic spermatogenesis of allotriploid males between japanese and european water frogs. | of 21 allotriploid males that possessed two genomes of rana nigromaculata and one genome of rana lessonae 10 produced a large number of spermatozoa in their testes. when 4 of these males were backcrossed with a female of r. nigromaculata, all of the resulting froglets were diploid in chromosome number and were completely r. nigromaculata type in appearance. these allotriploid males proved to have produced spermatozoa with one r. nigromaculata genome hybridogenetically. therefore, their germ line ... | 1993 | 8458253 |
| complete nucleotide sequence and gene rearrangement of the mitochondrial genome of the japanese pond frog rana nigromaculata. | in this study, we determined the complete nucleotide sequence of the mitochondrial genome of the japanese pond frog rana nigromaculata. the length of the sequence of the frog was 17,804 bp, though this was not absolute due to length variation caused by differing numbers of repetitive units in the control regions of individual frogs. the gene content, base composition, and codon usage of the japanese pond frog conformed to those of typical vertebrate patterns. however, the comparison of gene orga ... | 2001 | 11817647 |
| mechanical, electrical, and morphological characteristics of skeletal muscle fibers from xenopus and other species of frogs. | mechanical, electrical, and morphological properties of iliofibularis or semitendinosus of xenopus laevis, rana catesbeiana, and rana nigromaculata were investigated in an attempt to find out the differences between them which will give the basic knowledge for the study of excitation-contraction coupling. with application of electrical stimulation, a single muscle fiber from xenopus contracted at a faster rate of rise than did the other muscles tested. the maximum rate of rise (tmax) of tension ... | 1983 | 6606063 |
| [the infection status of sparganum and gnathostoma in frogs of southern part of korea] | a survey on the infection status of sparganum and gnathostoma in frogs was carried out in 11 areas in gyeongsangnam-do and cheonlanam-do province, a southern part of korea. 1. among 626 frogs examined, 4 percent were infected with sparganum, but none with gnathostoma. the infection rates of sparganum were variable according to the areas. those from kimhae, sunchun, jinhae, sachun, kosung, keoje, and hadong were 16 %, 9.1 %, 9.1 %, 4.1 %, 2 %, 2 %, and 1.5 % respectively, but frogs from hapchun, ... | 1983 | 12902672 |
| recovery of viability in triploid hybrids between japanese and european water frogs, and their reproductive capacity. | diploid and triploid hybrids, consisting of the various combinations of chromosome set and cytoplasm between rana nigromaculata and rana lessonae, were generated in order to study their viability and reproductive capacity. reciprocal diploid hybrids and allotriploids, which had two lessonae genomes and one nigromaculata genome in nigromaculata cytoplasm, all died without closing their neural folds. allotriploids, which had two nigromaculata genomes and one lessonae genome in nigromaculata cytopl ... | 1993 | 8492084 |
| segmentina (polypylis) hemisphaerula (gastropoda: planorbidae): a new molluscan intermediate host of a human intestinal fluke neodiplostomum seoulensis (trematoda: diplostomatidae) in korea. | three species of the pulmonate snails of the family planorbidae have been reported from korea, gyraulus convexiusculus, hippeutis (helicorbis) cantori, and segmentina (polypylis) hemisphaerula. of these 3 species, only h. cantori is reported as the molluscan intermediate host of neodiplostomum seoulensis, 1 of the important snail-borne human intestinal trematodes in korea. however, s. hemisphaerula was also found to be an intermediate host for n. seoulensis. in field-collected snails, h. cantori ... | 1996 | 8604110 |
| blood parasites of amphibians from sichuan province, people's republic of china. | two hundred forty-six amphibians from sichuan province, people's republic of china, were examined for blood parasites between april and june 1990. six trypanosome species were found, 2 of which were not identified because of poor material. trypanosoma rotatorium (sensu mayer, 1843) was found in rana limnocharis and rana nigromaculata. trypanosoma chattoni and a t. rotatorium-like species were found in bufo gargarizans. a sphaeromastigote similar to trypanosoma tsunezomiyatai was seen in r. limno ... | 1993 | 8501591 |
| melanosome formation in cultured amelanotic melanophores of rana brevipoda by a frog tyrosinase cdna transfection. | a cdna encoding tyrosinase of rana nigromaculata was introduced into cultured, tyrosinase-negative amelanotic melanophores of r. brevipoda by a calcium phosphate precipitation method. within a few days following transfection, dark pigmentation became visible in a small number of cells. light microscopic observation revealed that the morphology of these transformed cells was comparable to that of normal melanophores in culture, and their proliferative activity was lower than that of amelanotic ce ... | 1995 | 8610069 |
| analysis of the tyrosinase gene of the japanese pond frog, rana nigromaculata: cloning and nucleotide sequence of the genomic dna containing the tyrosinase gene and its flanking regions. | three genomic dna fragments containing the tyrosinase-encoding gene (tyr) of the japanese pond frog, rana nigromaculata, were cloned. the first, clone i, was isolated from a genomic library of sperm dna using the mouse tyr cdna as the probe and contained a dna segment similar to exon 4 of the mouse tyr gene. subsequently, the tyr cdna was isolated by screening a frog embryo cdna library using clone i as the probe. two clones that contain genomic dna of the tyr gene were isolated also from a bloo ... | 1995 | 7772385 |
| testicular cycles in three species of korean frogs: rana nigromaculata, rana rugosa, and rana dybowskii. | seasonal changes in testicular structure and function in three species of korean frogs (rana nigromaculata, r. rugosa, and r. dybowskii) having different breeding seasons and habitats were examined throughout the year. r. nigromaculata live in rice fields and breed in early may. their gonadosomatic index (gsi) and testis weight decreased slightly from may until july, but increased markedly from august to high levels through december. the diameter (cross-sectional area) of seminiferous tubules ch ... | 1998 | 9707480 |
| the development of the olfactory organ of kaloula borealis (barbour) as compared with that of rana nigromaculata hallowell. | | 1946 | 20998714 |