| [evaluation of the reflectometric method using the skin of the toad bufo arenarum in vitro for the determination of plasma msh]. | the aim of the present paper was to investigate the following points, by using the reflectometric bioassay for melanocyte-stimulating hormone (msh) with skin of the toad bufo arenarum: (1) to study if solutions of alpha-msh prepared in rat plasma and amphibian ringer, or dilutions of plasma overloaded with endogenous msh, could render in acceptable dose-response lines. 2) to investigate if acth at a very high level of plasma concentration could interfere in the bioassay 3) observing if the stora ... | 1978 | 233497 |
| ["natural" and "immune" heteroagglutinins in bufo arenarum hensel: their fractionation by means of human and pig red cells (author's transl)]. | | 1975 | 806980 |
| effects of atrial natriuretic peptide and toad heart extract on isolated toad bufo arenarum aortic rings. | the vascular effects of synthetic atrial natriuretic peptide (anp) (ranp-99-126), and toad heart extract (the) were examined on isolated toad aortic rings from the toad bufo arenarum. anp inhibited contraction produced by human angiotensin ii (at ii), norepinephrine (ne), and arginine vasopressin (avp) in isolated toad aortic rings. the present data show that a relaxant effect of anp could be obtained also in the noncontracted aortic smooth muscle of toad if it had been previously challenged wit ... | 1992 | 1490588 |
| [experimental evolutive cycle of diphyllobothrium erinaceieuropei in paracyclops fimbriatus, tadpoles of bufo arenarum and dogs]. | experiments were performed in order to develop the life cycle of diphyllobothrium erinaceieuropei rudolphi 1819 (cestoda, pseudophyllidea) in paracyclops fimbriatus and bufo arenarum as intermediate hosts and dogs as definitive hosts. the eggs of diphyllobothrium erinaceieuropei from faeces of naturally infected dogs were kept refrigered, in water. in order to obtain coracidiums they were incubated at 25 degrees c, and then were placed in a flask which contained paracyclops fimbriatus. the copep ... | 1989 | 2516918 |
| sex steroid binding protein from bufo arenarum: further characterization. | the effects of temperature, ph, divalent cations, 2-mercaptoethanol (et-sh), n-ethylmaleimide (nem), and phenylmethylsulfonyl fluoride (pmsf) on the dihydrotestosterone (dht) binding to sex steroid binding protein from bufo arenarum (basbp) were examined. the temperature curve indicated that the binding remained stable up to 50 degrees c and the ph curve showed maximum binding between ph 7 and 9. the incubations of basbp with divalent cations, nem and et-sh demonstrated that basbp require disulf ... | 1986 | 2878765 |
| prolactin binding sites in the brain and kidneys of the toad, bufo arenarum hensel. | (125i)-ovine prolactin (oprl) binding was found in several brain areas of the toad, bufo arenarum hensel. the olfactory bulb, cerebral hemispheres, and both dorsal and ventral mesencephalic regions showed saturable, high affinity, (125i)-oprl binding, ranging between 5.6 to 29.9 fmol/mg protein, while the association constant (ka) by scatchard analysis was between 4.0 to 8.7 x 10(9) m-1. this binding was compared with the scatchard plot of the kidney, which has been already described by other gr ... | 1985 | 3016041 |
| lipid metabolic pathways operating in amphibian full-grown oocytes. | the utilization of (2-3h)-glycerol in lipid biosynthesis was analyzed in bufo arenarum and xenopus laevis full-grown oocytes. the precursor was more actively incorporated in xenopus laevis oocytes. neutral glycerides were the lipids displaying the highest levels of radioactivity followed by phosphatidylcholine and phosphatidylethanolamine. after reincubation of prelabeled oocytes in a saline buffer solution, a net fall in labeled phosphatidic acid concomitant with an increase in phosphatidylchol ... | 1987 | 3103976 |
| a developmentally regulated lectin in bufo arenarum embryos. | we report the levels of an endogenous beta-galactoside lectin activity from bufo arenarum whole embryos extracts and specific inhibition by saccharides at different developmental stages. specific activity measured against trypsinized rabbit red blood cells showed relatively high and fluctuating levels during early stages (up to about 76 h post-fertilization) which fell to significantly lower and more constant values at late stages (77-264 h post-fertilization). lactose is the most potent inhibit ... | 1987 | 3137989 |
| absence of dna in yolk platelets of bufo arenarum oocytes. | the absence of dna in the yolk platelets of bufo arenarum oocytes was verified. oocytes from the coelomic cavity were used in order to avoid possible contamination by the ovarian tissue. four methods for dna analysis were employed, and the possibility of interference was carefully checked. the presence of three possible contaminants, which produced positive reactions from the dna analysis, was detected. these were the glycosaminoglycan from the superficial layer of the platelets, sucrose, and po ... | 1985 | 3932584 |
| characterization of a sexual steroid binding protein in bufo arenarum. | reproductively active female bufo arenarum possess a serum protein (sbp) that binds testosterone, dihydrotestosterone, and estradiol with high affinity and capacity. the binding capacity values are two orders of magnitude higher than those found in human serum. the specificity of b. arenarum sbp is comparable to human sbp with the exception that it has a high affinity for the synthetic androgen methyltrienolone (r1881). the physicochemical characterization of sbp indicates a stokes radius of 43. ... | 1985 | 3934028 |
| [effects of cadmium on the development of an amphibian]. | the effects of continuous treatment with cadmium on bufo arenarum embryos from the 2-cell stage onwards, were evaluated by light and scanning electron microscopy. damages were concentration-dependent (between 0.03 and 4.00 mg cd++/l in 10% holtfreter's solution) and ranged between teratogenic effects and lethality. in the 0.50-4.00 mg cd++/l range high mortality, delayed development and significant alterations in the gastrulation and neurulation processes were observed. in embryos maintained at ... | 1985 | 3939390 |
| the renin-angiotensin system in bufo arenarum and bufo paracnemis. | | 1971 | 4398993 |
| [effects of pms and hcg on testicular ascorbic acid content in bufo arenarum hensel]. | | 1971 | 5000999 |
| [globular volume and osmotic resistance of human and bufo arenarum hensel erythrocytes]. | | 1968 | 5744870 |
| cell mediated immune response of bufo arenarum and leptodactylus ocellatus (amphibia, anura) to mycobacterial antigens. | the lymphocyte transformation test was applied to the study of cell mediated immune (cmi) response in vitro to mycobacterial antigens in bufo arenarum and leptodactylus ocellatus previously inoculated with a suspension of mycobacterium tuberculosis. the stimulated samples of blood both in b. arenarum and l. ocellatus showed a significant increase in the percent of blastic dedifferentiation (almost 100% with respect to controls) suggesting the presence of a positive cmi response to ppd. the diffe ... | 1984 | 6141025 |
| stimulation of adenosine 3',5'-monophosphate formation in mononuclear leukocytes by toad venoms. | the content of adenosine 3',5'-monophosphate in human mononuclear leukocytes was enhanced 3-5-times by venoms obtained from african toad (bufo africanus), american toad (bufo americanus), colorado river toad (bufo arenarum) and marine toad (bufo marinus) at 25 micrograms/ml for 5 min of incubation at 37 degrees c. the maximum stimulation was observed after 1-5 min of incubation. the half-maximal stimulation was observed at 0.1 micrograms/ml venom obtained from colorado river toad (bufo arenarum) ... | 1982 | 6184077 |
| vascular responses to angiotensins in the toad. role of the adrenergic system. | the isolated hindlimbs (vasoconstrictor) and the whole toad pressor assays were used to investigate the effects of some angiotensin ii (at ii) analogues and the influence of the adrenergic system on the vascular response to at ii in the toad bufo arenarum. three of the analogues assayed (leu8at ii, sa1, ala8at ii, sar1, i1e8at ii) were unable to block the response to at ii, and a fourth, ala1, ile8at ii, potentiated it. in the case of sar1, ala8at ii (saralasin), this confirms previous negative ... | 1983 | 6412251 |
| effects of frog-skin angiotensin ii in amphibians. | the role of frog-skin angiotensin ii (aii) in amphibia was studied by comparing the sodium and water permeability effects of three angiotensins (aii): frog skin (ala-pro-gly-[ile3, val5]-ang ii), human [( asp1, ile5]-aii), and japanese goosefish [( asn1-val5]-aii). frog-skin aii increased the short-circuit current (scc) significantly after it was added to the dermal side of the isolated skin of the south american frogs, leptodactylus chaquensis and ocellatus, and the toad, bufo arenarum, in conc ... | 1983 | 6418648 |
| spatial and structural interrelationships between secretory cells of the subcommissural organ and blood vessels. an immunocytochemical study. | in 76 specimens (amphibians, reptilians, mammals) belonging to 25 different vertebrate species, the region of the subcommissural organ (sco) was investigated with the use of a primary antiserum raised against an extract of bovine reissner's fiber + the immunoperoxidase procedure according to sternberger et al. (1970). in the sco of a toad (bufo arenarum) and several species of reptiles (lacertilians, ophidians, crocodilians), the ependymal cells were the only type of secretory cell displaying va ... | 1984 | 6435877 |
| comparative study of igfbp properties in toad and rat sera. | the levels of igf-i have been simultaneously measured by radioimmunoassay in samples of the toad bufo arenarum and of normal male wistar rats. in addition, the different fractions of igf-i binding proteins (igfbp) and their binding properties have been identified by ligand blot and scatchard analysis in the serum of both species. in the toad, we have measured levels of igf-i (2.78 +/- 0.48 ng/ml) similar to those previously reported in amphibians but far below those found in rats. igfbp levels w ... | 1993 | 7506683 |
| water permeability properties of the ovarian oocytes from bufo arenarum and xenopus laevis: a comparative study. | the water permeability properties of ovarian oocytes from xenopus laevis and bufo arenarum, a toad species found in the buenos aires region, were studied. we report that: (i) the water osmotic permeability (pf, cm/sec x 10(-4)) was significantly higher in bufo (6 degrees c = 12.3 +/- 2.4; 18 degrees c = 20.8 +/- 4.8) than in xenopus oocytes (6 degrees c = 5.3 +/- 0.3; 18 degrees c = 6.2 +/- 1.6). the corresponding water diffusion permeability values (pd, cm/sec x 10(-4)) were: xenopus = 2.3 +/- ... | 1994 | 7529323 |
| distribution of mrna encoding the fa-chip water channel in amphibian tissues: effects of salt adaptation. | a water channel, the frog aquaporin-chip (fa-chip) was recently cloned from rana esculenta urinary bladder. the 28.9 kda encoded protein shows 78.8%, 77.4%, 42.4% and 35.6% identity with rat chip28, human chip28, rat wch-cd and gamma-tip, other members of the new transmembrane water channel family (aquaporin-chip). we have now studied membranes from different frog (r. esculenta) organs employing semiquantitative pcr using fa-chip specific primers and an internal standard to quantify the pcr prod ... | 1995 | 7539499 |
| galanin-like immunoreactive expression in the central nervous system of the toad. | the distribution of galanin (gal)-like immunoreactivity (-li) was studied in the cns of the toad (bufo arenarum hensel). tissue sections were incubated with antibodies directed toward rat or porcine gal and processed either for the avidin-biotin complex, or for the indirect immunofluorescence techniques. in the telencephalon gal-immunoreactive (-ir) perikarya were observed in the ventral part of the striatum and in the septal accumbens nuclei. immunopositive neurons were also observed in the med ... | 1995 | 7550577 |
| an in vitro model suitable for studying insulin secretion in amphibians. | the aim of this work was to develop an in vitro model suitable for studying insulin secretion in amphibians and for identifying agents capable of either blocking or stimulating such a process in this group. for this purpose, pancreases from the toad bufo arenarum were incubated for 60 min at 25 degrees with several insulin secretagogues and blockers, and the immunoreactive insulin released into the medium was measured by radioimmunoassay. under these experimental conditions, metabolic (glucose, ... | 1995 | 7635265 |
| characterization and properties of steroid binding protein in bufo arenarum serum. | serum steroid binding properties of mature bufo arenarum females were studied. binding data obtained using charcoal adsorption assay and equilibrium dialysis methods indicates a single protein, named bufo arenarum sex binding protein (ba sbp), which binds 5 alpha-dihydrotestosterone (dht), testosterone (t), and estradiol-17 beta (e2) with high affinity (10(-7) m-1 - 10(8) m-1) and fair capacity (10(-6) m). scatchard plot analysis demonstrated the coexistence of two binding sites. ba sbp has a se ... | 1994 | 7980944 |
| learning under partial reinforcement in the toad (bufo arenarum): effects of lesions in the medial pallium. | two experiments studied the adjustment of toads (bufo arenarum) to partial reinforcement in a runway. in experiment 1, two groups received 24 daily trials of either continuous reinforcement (cr) or 50% partial reinforcement (pr). training parameters that facilitate the pr extinction effect (greater resistance to extinction after pr than cr training) in rats were selected. pr impaired performance during acquisition but had no effect on performance during extinction relative to cr. in experiment 2 ... | 1994 | 8129684 |
| purification, characterization and partial sequencing of the heart fatty acid-binding protein from bufo arenarum. | a 15.7 kda fatty acid-binding protein from toad heart was purified by gel-filtration chromatography on sephadex g-75 followed by anion-exchange chromatography on a mono-q column. purity was confirmed by gel electrophoresis and isoelectric focusing. molecular mass, isoelectric point, amino acid composition and partial internal sequence showed that the protein is related to mammalian heart fatty acid-binding proteins. | 1994 | 8205381 |
| effects of lesions in the medial pallium on instrumental learning in the toad (bufo arenarum). | lesions of the medial pallium in toads significantly retarded extinction of a water-reinforced instrumental response in a runway training situation, relative to sham-operated and intact controls. the lesion had no effect on acquisition or in the amount of water uptake during acquisition. the results suggest that the medial pallium of toads plays a role in response inhibition. this possibility is discussed in relation to the results of analogous experiments with hippocampectomized rats. | 1993 | 8327601 |
| immunocytochemical and morphometric study on the changes of tsh, prl, gh and acth cells during the development of bufo arenarum. | the development and dynamics of thyrotropin (tsh), adrenocorticotropic hormone (acth), prolactin (prl), and growth hormone (gh) cells have been studied using immunocytochemical techniques and rabbit antisera, raised against the relevant human hormone, in the pars distalis of bufo arenarum larvae at different stages of development. the four types of cells studied were identified in different zones of the pars distalis: tsh cells occurred mainly in the centro-ventral zone, acth cells in the rostra ... | 1996 | 8581952 |
| presence and release of immunoreactive atrial natriuretic peptide (anp) in bufo arenarum spermatozoa after hcg treatment. | atrial natriuretic peptide (anp)-like immunoreactivity has been demonstrated in mature spermatozoa of bufo arenarum. however, after spermiation induced by gonadotropin releasing hormone (gnrh), no anp immunoreactivity was detected in testicular spermatozoa. recently, the presence of gnrh and gnrh receptors in amphibian testes has been demonstrated. to clarify if the loss of anp-like immunoreactivity in spermatozoa is a direct effect of gnrh or pituitary gonadotropins, a study on bufo arenarum ad ... | 1996 | 8653157 |
| vitelline envelope formation during oogenesis in bufo arenarum. | the formation of vitelline envelope (ve) during the oogenesis of bufo arenarum (amphibia anura) is described. at the stage of early vitellogenesis, the first structures appear: the number of oocyte microvilli increases, and many cross sections of them are observed between the follicle cells and the oocyte. a filamentous material is observed inside the follicle cells and between the follicle cells and the oocyte. multivesicular bodies are also found in the follicle cells, and in the perivitelline ... | 1996 | 8653159 |
| ecotoxicity in the reconquista river, province of buenos aires, argentina: a preliminary study. | the reconquista river in argentina is considered a "supercritical" river basin due to environmental degradation. within its valley of 1.547 km2, there are more than 3 million inhabitants and 12,000 industries. using early-life-stage toxicity tests with bufo arenarum embryos (the most sensitive of three native species), we determined the water quality at six sampling stations of the river valley and expressed the results as acute and chronic toxicity units. along most of the river, the toxicity w ... | 1996 | 8820587 |
| progesterone inhibition of water permeability in bufo arenarum oocytes and urinary bladder. | the ovarian oocytes from bufo arenarum (bao) but not those from xenopus laevis (xlo) would have water channels (wc). we now report that the injection of the mrna from bao into the oocytes from xlo increased their water osmotic permeability (pi) (reduced by 0.3 mm hgcl2 and reversed by 5 mm beta-mercaptoethanol). a 30-min challenge with progesterone induced, 18 h later, a reduction of the mercury-sensitive fraction of pf in the bao (but not in xlo). the mrna from bao pretreated with progesterone ... | 1996 | 8928851 |
| amphibian bufo arenarum vitronectin-like protein: its localization during oogenesis. | in the present study, we analyzed the localization of vitronectin-like protein in oocytes during oogenesis as well as in the serum and liver tissue of the amphibian bufo arenarum. vitronectin-like protein was purified from serum by heparin-affinity chromatography and showed to have the two biological properties in common with most animal vitronectins (vn): heparin binding activity and an rgd-dependent cell-spreading activity. sds-page of vitronectin-like protein revealed that it consists of two ... | 1996 | 8946247 |
| the primary structure and carbohydrate specificity of a beta-galactosyl-binding lectin from toad (bufo arenarum hensel) ovary reveal closer similarities to the mammalian galectin-1 than to the galectin from the clawed frog xenopus laevis. | the detailed characterization of a galectin from the toad (bufo arenarum hensel) ovary in its primary structure, carbohydrate specificity, and overall biochemical properties has provided novel information pertaining to structural and evolutionary aspects of the galectin family. the lectin consists of identical single-chain polypeptide subunits composed of 134 amino acids (calculated mass, 14,797 daltons), and its n-terminal residue, alanine, is n-acetylated. when compared to the sequences of kno ... | 1996 | 8955156 |
| evidence for the presence and participation of 85-75 kda extracellular matrix components in cell interactions of bufo arenarum gastrulation. | we studied the presence and distribution of the extracellular materials (ecm), obtained by mild embryonic dissociation through nondenaturing and denaturing page, immunoblotting and immunocytochemical wholemount in the gastrulation of anuran amphibian bufo arenarum. the sds-page, under reducing conditions, revealed the protein profile of the ecm which comprised six bands. the western immunoblotting effected with antibodies against fibronectins (fn) of xenopus laevis, ambystoma mexicanum and bufo ... | 1997 | 9062995 |
| bufo arenarum egg jelly coat: purification and characterization of two highly glycosylated proteins. | egg jelly coats from bufo arenarum are formed by components secreted along the oviduct. these secretion products overlay the oocytes as they transit along the different oviductal portions. in this study, we have isolated two highly glycosylated proteins of the jelly coat, which are secreted almost all the way along the oviduct. both glycoproteins [designated as highly glycosylated protein (hgp) and low-molecular-mass highly glycosylated protein (l-hgp)] were purified to homogeneity, from the sec ... | 1997 | 9173897 |
| structural analysis of oligosaccharide-alditols released by reductive beta-elimination from the jelly coats of the anuran bufo arenarum. | amphibian egg jelly coats are formed by components secreted along the oviduct. these secretion products overlay the oocytes as they are transported toward the cloaca. mucin type glycoproteins are the major constituents of the egg jelly coats. in this study, the o-linked carbohydrate chains of the jelly coat surrounding the eggs of bufo arenarum were released by alkaline borohydride treatment. fractionation of the mixture of o-linked oligosaccharide-alditols was achieved by a combination of chrom ... | 1998 | 9523696 |
| hematological parameters in bufo arenarum injected with sublethal dose of lead acetate. | lead has been recognized as a high risk toxic for most organisms including human. the effects of pb in non-mammalian vertebrates are poorly known, particularly in anuran amphibians. the purpose of this study was to determine the effect of this metal on some hematological parameters of adult bufo arenarum. it was found that all parameters remained unaltered within normal ranges, with the exception of reticulocyte counts which was significantly increased compared to the in controls (3.7% vs. 0.2%) ... | 1998 | 9559104 |
| further studies on vertebrate s-type lectins: cross-reactivity between toad and human lectins. | galectins (s-type or s-lac lectins) are a well-defined family of beta-galactoside animal lectins characterized by a high sequence homology in the carbohydrate-binding domain. we have previously purified and characterized the s-type lectin from the ovary of the toad bufo arenarum. in this study, we purified the s-type lectins from bufo arenarum ovary and human spleen by an improved method which included ion exchange and affinity chromatography. antibody cross-reactivities between both lectins and ... | 1997 | 9711320 |
| red blood cell osmotic fragility in bufo arenarum exposed to lead. | the effects on red blood cells of a single sublethal dose of pb of 100 mg kg-1 administrated to adult bufo arenarum were studied. the blood d-aminolevulinic acid dehydratase (d-alad) activity, the red blood cell (rbc) osmotic fragility (of), and the hematocrit (hct) were measured in control and lead poisoned toad. the enzyme d-alad is considered as a specific biomarker for human and animals lead exposure. in bufo, lead also provoked a significant decrease in the d-alad activity without changes i ... | 1998 | 9783056 |
| copper toxicity and copper-zinc interactions in amphibian embryos. | the copper hazard was evaluated by means of a 7-day toxicity test with bufo arenarum embryos. the lc50 and lc10 values from 24 to 168 h of exposure were approx. 0.085 and 0.05 mg cu2+/1, respectively, while the lc90 resulted in 0.155 mg cu2+/1 but in this case from 96 h onwards the lc90 diminished up to approx. 0.105 mg cu2+/1. these data plotted as toxicity profiles (top) provide a better understanding of concentration and time-dependent thresholds. for instance, exposure threshold occurs withi ... | 1998 | 9810731 |
| modulatory effect of hormones on insulin secretion in vitro in the toad. | the aim of this work was to demonstrate the possible direct effect of several hormones upon glucose-induced insulin secretion in amphibians. hence, pancreas pieces of bufo arenarum were incubated for 60 min at 25 degrees with 2 and 8 mm glucose plus the addition of hormones known to affect insulin secretion in mammals, measuring the release of insulin by radioimmunoassay. glucagon (1 microm), acth (2.5 microm), human and bovine growth hormone (4.6 and 2.1 microm), prolactin (0.27 microm), cortic ... | 1998 | 9827019 |
| ultrastructural analysis and cytochemical localization of atrial natriuretic peptide-stimulated guanylate cyclase in internal gills of bufo bufo tadpoles. | in this study on the internal gills of the larvae of bufo bufo we examined the ultrastructural features and, using cytochemical methods, showed the localization of guanylate cyclase in the presence of atrial natriuretic peptide. the gill apparatus consists of a series of arches each with a dorsal part or gill rakers with filtering and glandular functions. in the epithelium, cells were found that contain granular secretions similar to those atrial natriuretic factor-immunoreactive granules of lar ... | 2000 | 10550800 |
| a simple procedure for isolation of bufo arenarum c3 complement fraction and preparation of antiserum. | because of the need for antibodies in our studies involving the third component of complement in bufo arenarum, we performed a simple procedure to purify c3 from b. arenarum serum to use as antigen in the preparation of the antiserum. the strategy was based on the well-known ability of c3 to bind to zymosan (zy), a yeast cell wall extract comprised of polysaccharides. the zy-bound fraction showed cross reactivity with a commercial antibody to human c3 as well as a similar electrophoretic profile ... | 1999 | 10579641 |
| participation of the gm1 ganglioside in the gastrulation of anuran amphibian bufo arenarum. | in the present paper we established the ganglioside composition of the blastula and gastrula stages of the anuran amphibian bufo arenarum, two relevant stages characterized by dynamic changes in morphology and cellular rearrangements. densitometric studies evidenced that gd1a and gt1b were the more abundant gangliosides of the blastula embryos whereas gm1 and gm2 were the predominant species in gastrula embryos. analysis of ganglioside abundance indicates that the "a" and "b" synthesis pathways ... | 2000 | 10684569 |
| corticotropin-releasing factor accelerates metamorphosis in bufo arenarum: effect on pituitary acth and tsh cells. | the actions of several neuropeptides as hypothalamic mediators in the regulation of bufo arenarum metamorphosis were investigated. prometamorphic larvae were injected with 1.5 microg thyrotropin-releasing hormone (trh), 2 microg ovine corticotropin-releasing factor (ocrf), 2 microg mammalian gonadotropin-releasing hormone (mgnrh), 2 microg human growth hormone-releasing hormone (hghrh), or holtfreter solution (control group). larvae received two injections with the same dose: one at the beginnin ... | 2000 | 10684570 |
| the lung of the common toad, bufo arenarum (anura: bufonidae). a light and electron microscopy study. | the present study describes the lung morphology of the common toad, bufo arenarum, as observed by light and electron microscopy. the lung wall consists of four layers: mesothelium, dense connective tissue with thin elastic fibers, loose connective tissue containing smooth muscle fibers and an internal respiratory epithelium. the lung presents three types of folds defined by their epithelia. first order folds are coated by ciliated epithelium containing numerous goblet cells. second order folds p ... | 1998 | 10904523 |
| involvement of blood serum in amphibian fertilization. | a proteolytic enzyme secreted by the first portion of amphibian oviduct, pars recta, called oviductin in xenopus laevis, causes ultrastructural alterations on the extracellular matrix of coelomic eggs, turning them susceptible to fertilization. although great advances have been made in the field of reproduction, the molecular mechanisms responsible for the fusion between the egg and the sperm are yet to be understood. we have recently demonstrated the presence of proteins from pars recta fluid i ... | 1998 | 10904526 |
| human chorionic gonadotropin-induced spermiation in bufo arenarum is not mediated by steroid biosynthesis. | this study employed an in vitro system to identify potential steroidal mediators of spermiation in bufo arenarum. testicular fragments were incubated for 2 h at 28 degrees. spermiation was induced by 10 iu human chorionic gonadotropin (hcg) and the effect of different inhibitors of steroid biosynthesis was analyzed. cyanoketone (10(-5)-10(-6) m), an inhibitor of 3-oxo-4-ene steroid biosynthesis, did not block hcg-inducing activity even when biosynthesis of 3-oxo-4-ene steroids and its reduced me ... | 2000 | 10936036 |
| potential involvement of c(3) complement factor in amphibian fertilization. | we have assessed the potential involvement of c(3), the third complement factor, and its receptor in bufo arenarum fertilization. we show that a polyclonal antibody against a b. arenarum c(3)-like factor (c(3)ba) reacts specifically with components of the extracellular matrix (ecm) of coelomic eggs and the cell membrane of uterine eggs. interestingly, we have identified a 163 kd protein immunoreactive with a monoclonal antibody against the cd11b alpha chain of the human c(3) receptor on the cell ... | 2000 | 10996815 |
| primary structure and developmental expression of bufo arenarum cellular nucleic acid-binding protein: changes in subcellular localization during early embryogenesis. | a bufo arenarum cellular nucleic acid-binding protein (bcnbp) full-length cdna was cloned. bcnbp is a 19.4 kda protein containing seven cchc zinc finger motifs, an rgg box and a ser-rich region. amino acid comparisons showed high values of homology in vertebrates and smaller values in insects or inferior eukaryotes. northern blot analysis during oogenesis and early development revealed two transcripts with different expressions of pattern behavior. one of them is present in all stages analyzed, ... | 2001 | 11148448 |
| tadpoles assay: its application to a water toxicity assessment of a polluted urban river. | the acute toxicity assay with premetamorphic tadpoles of bufo arenarum as sentinel organism was applied to evaluate the quality of two water samples taken from three sites of the reconquista river, an urban watercourse which is recipient of both untreated industrial effluents and domestic wastes. the results of the 96 hr bioassays were compared with the physicochemical parameters determined in the samples. mortality rates in each sample were compared using the bonferroni's test and a stepwise re ... | 2001 | 11336412 |
| blood lead content in a peri-urban population of the south american toad bufo arenarum. | blood pb concentration in a south american toad bufo arenarum population (n = 152) was determined over 10 samplings carried out between december 1996 and november 1999. the studied population lived in the surroundings of the la plata city, the largest industrial-urban setting of the buenos aires province, argentina. the presence of the metal was detected in all the samples tested, the mean concentration range being 1.99-4.66 mg dl(-1). some preliminary environmental data on soil content of pb in ... | 2001 | 11346044 |
| lack of teratogenicity of microcystin-lr in the mouse and toad. | microcystin-lr (mc-lr) is a cyanobacterial toxin generated by the organism microcystis aeruginosa. although the hepatotoxicity of this chemical has been characterized, the potential developmental toxicity in vertebrates has not been well studied. the purpose of this study was to elucidate the effects of this toxin on the in vivo and in vitro development of mammals and the development of an anuran (toad). initial acute toxicity experiments with female cd-1 mice were accomplished with mc-lr admini ... | 2002 | 11807924 |
| species-specificity of amphibia carbohydrate chains: the bufo viridis case study. | the jelly coat surrounding the eggs of amphibia is composed of oviducal mucins and plays an important role in the fertilization process. from a structural and chemical point of view, these jellies are very different from one species to another. bufo viridis is the 13th amphibia species studied in term of carbohydrate structural analysis. the oligosaccharides have been released from the oviducal mucins by reductive beta elimination, purified by various chromatography procedures and analyzed by (1 ... | 2002 | 11814443 |
| membrane currents in the oocyte of the toad bufo arenarum. | the amphibian oocyte cell model is widely used for heterologous expression of ionic channels and receptors. little is known, however, about the physiology of oocyte cell models other than xenopus laevis. in this study, the two-electrode voltage clamp technique was used to assess the most common electrical patterns of oocytes of the south american toad bufo arenarum. basal membrane resistance, resting potential, and ionic currents were determined in this cell model. the oocyte transmembrane resis ... | 2002 | 11857475 |
| vitelline envelope of bufo arenarum: biochemical and biological characterization. | vitelline envelopes (ves) of bufo arenarum were isolated in order to study their composition and their role in fertilization. ves are composed of four glycoproteins, with molecular masses of 120, 75, 41, and 38 kda. to characterize its biological properties, we quantitatively determined sperm-ve binding and the induction of the acrosome reaction. heterologous binding of b. arenarum sperm to xenopus laevis ve components was observed with about one-third the efficiency of homologous binding. equiv ... | 2002 | 11906942 |
| in vitro hcg and human recombinant fsh actions on testicular steroidogenesis in the toad bufo arenarum. | in order to study the regulation of testicular steroidogenesis in the toad bufo arenarum, the effect of gonadotropins (hcg and hrfsh) on steroidogenic enzymes was determined using an in vitro system. 3beta-hydroxysteroid dehydrogenase/isomerase activity was not affected by any of the gonadotropins, at any of the concentrations used. in contrast, 5alpha-reductase activity was strongly reduced by both hcg and hrfsh. human chorionic gonadotropin inhibited the activity of cytochrome p450 17alpha-hyd ... | 2002 | 12093119 |
| an enzyme-linked immunosorbent assay for measuring anti-sheep red blood cells antibodies in lead-exposed toads. | immune function assays to screen immunotoxic effects of xenobiotics has recently become of major interest. in the framework of our studies, we standardized methods to quantify the humoral response of an amphibian species (bufo arenarum, amphibia, anura) exposed to sublethal lead (as acetate). | 2002 | 12459152 |
| characterization of urea transport in bufo arenarum oocytes. | xenopus laevis oocytes have been extensively used for expression cloning, structure/function relationships, and regulation analysis of transporter proteins. urea transporters have been expressed in xenopus oocytes and their properties have been described. in order to establish an alternative system in which urea transporters could be efficiently expressed and studied, we determined the urea transport properties of ovarian oocytes from bufo arenarum, a toad species common in argentina. bufo oocyt ... | 2003 | 12840834 |
| antibacterial activity of lactose-binding lectins from bufo arenarum skin. | amphibians respond to microbial infection through cellular and humoral defense mechanisms such as antimicrobial protein secretion. most humoral defense proteins are synthetized in the skin. in this study we isolated two beta-galactoside-binding lectins with molecular weights of 50 and 56 kda from the skin of bufo arenarum. these lectins have significant hemagglutination activity against trypsinized rabbit erythrocytes, which was inhibited by galactose-containing saccharides. they are water-solub ... | 2003 | 12847913 |
| effect of lead acetate on the in vitro engulfment and killing capability of toad (bufo arenarum) neutrophils. | lead is an element of risk for the environment and human health and has harmful effects that may exceed those of other inorganic toxicants. the immune system is one of the targets of lead. its immunomodulatory actions depend on the level of exposure, and it has been demonstrated that environmental amounts of the metal alter immune function. very little information is available regarding the effect of the metal on different aspects of the immune system of lower vertebrates, in particular of amphi ... | 2003 | 14659456 |
| ecotoxicological assessment for receiving waters with the premetamorphic tadpoles acute assay. | the toxicity of receiving waters was evaluated by means of the young tadpoles assays. the sentinel organism was bufo arenarum, an indigenous anuran species. the assayed water samples were taken from a highly polluted urban watercourse (reconquista river, buenos aires, argentina), characterized by high concentration of nitrites, phosphates and heavy metals. the toxicity of water samples was assessed performing the pass-fail test and by means of the noec and lc(50); tus (toxic units) were also cal ... | 2005 | 15788180 |
| 11beta-hydroxysteroid dehydrogenase in the testis of bufo arenarum: changes in its seasonal activity. | in rat leydig cells, glucocorticoids (gc) inhibit testosterone (t) synthesis via glucocorticoid receptor (gr). however, gc access to gr is regulated by the local expression of 11beta-hydroxysteroid dehydrogenase (11beta-hsd). two isoforms were identified in mammals: type 1, a nadp+-preferring enzyme with k(m) in the mum range for gc and type 2, nad+-dependent, with k(m) in the nm range for gc. in amphibians, a seasonal rhythm in baseline gc levels was described. however, a shift in the amount of ... | 2005 | 16061069 |
| potential developmental toxicity of anatoxin-a, a cyanobacterial toxin. | some 2000 species of cyanobacteria (blue-green algae) occur globally in aquatic habitats. they are able to survive under a wide range of environmental conditions and some produce potent toxins. toxin production is correlated with periods of rapid growth (blooms) and 25%-70% of blooms may be toxic. anatoxin-a is an alkaloid neurotoxin that acts as a potent neuro-muscular blocking agent at the nicotinic receptor. acute toxicity, following consumption of contaminated water, is characterized by rapi ... | 2005 | 16127666 |
| effect of human gonadotropins on spermiation and androgen biosynthesis in the testis of the toad bufo arenarum (amphibia, anura). | this paper analyzes, in the toad bufo arenarum, the effect on spermiation and androgen secretion of two human recombinant gonadotropins, human recombinant lh (hrlh) and human recombinant fsh (hrfsh) as well as the well-known spermiation-inducing hormone, human chorionic gonadotropin (hcg). for this purpose, testes were incubated with different concentrations of hrlh (0.01-2.5 microg/ml) and hrfsh (0.05-5 microg/ml), and results were compared with those obtained with 2.5 microg/ml hcg. spermiatio ... | 2006 | 16358275 |
| serum protein profile and blood cell counts in adult toads bufo arenarum(amphibia: anura: bufonidae): effects of sublethal lead acetate. | lead is a multiple-source pollutant, well known for its toxicity, of great risk both for the environment and human health. the main target organs of lead are the hematopoietic, nervous, and renal systems; there are also reports in support of its impairment effects on the reproductive and immune systems. it is well known that most of the metal is accumulated in the blood cells and that many of the deleterious effects are related to its circulating concentrations. these adverse effects have been d ... | 2006 | 16446996 |
| characterization and biological properties of l-hgp, a glycoprotein from the amphibian oviduct with acrosome-stabilizing effects. | the role of the jelly coat that surrounds the amphibian oocytes has been widely discussed, but is poorly understood. the presence of the jelly coat is essential for fertilization. however, the structure and function of the molecules that comprise the jelly coat have not been thoroughly documented. l-hgp (low-molecular-mass highly glycosylated protein) is a highly glycosylated protein that is present in the jelly coat of the toad, bufo arenarum, oocytes and diffuses to the surrounding media. l-hg ... | 2006 | 16494580 |
| glycoproteins of the vitelline envelope of amphibian oocyte: biological and molecular characterization of zpc component (gp41) in bufo arenarum. | the vitelline envelope (ve) participates in sperm-egg interactions during the first steps of fertilization. in bufo arenarum, this envelope is composed of at least four glycoproteins, with molecular masses of 120, 75, 41, and 38 kda and molar ratio of 1:1.3:7.4:4.8, respectively. these components were isolated and covalently coupled to silanized glass slides in order to study their sperm-binding capacity. when considering the molar ratio of the glycoproteins in the egg-envelope and assuming that ... | 2007 | 17034049 |
| risk assessment of magnacide h herbicide at río colorado irrigation channels (argentina). tier 3: studies on native species. | we evaluated the potential environmental risk of the herbicide magnacide (baker petrolite, tx, usa) using native species from argentina, representing the ecosystem at the irrigation corporation (corfo) channels at the colorado river mouth, buenos aires, argentina. six species including fish, toads, snails, crustaceans, and insects were selected to perform studies on acute toxicity and repeated exposure effects. magnacide h susceptibility ranking was bufo arenarum (lethal concentration 50 [lc50] ... | 2007 | 17269476 |
| [anuran fauna from salta city, argentina]. | the loss and transformation of habitat by anthropogenic activities is one of the main causes of biodiversity decrease. amphibians are declining all over the world and one of the causes of this decline is thought to be habitat reduction. however, there are anuran populations in highly disturbed habitats, like cities. this study presents the ecological baseline needed to understand anuran communities in urban environments, for salta city. argentina (ca. 502,000 inhabitants). the sample was stratif ... | 2005 | 17354465 |
| cellular nucleic acid binding protein binds g-rich single-stranded nucleic acids and may function as a nucleic acid chaperone. | cellular nucleic acid binding protein (cnbp) is a small single-stranded nucleic acid binding protein made of seven zn knuckles and an arg-gly rich box. cnbp is strikingly conserved among vertebrates and was reported to play broad-spectrum functions in eukaryotic cells biology. neither its biological function nor its mechanisms of action were elucidated yet. the main goal of this work was to gain further insights into the cnbp biochemical and molecular features. we studied bufo arenarum cnbp (bcn ... | 2008 | 17661353 |
| changes in the antioxidant metabolism in the embryonic development of the common south american toad bufo arenarum: differential responses to pesticide in early embryos and autonomous-feeding larvae. | amphibians may be critically challenged by aquatic contaminants during their embryonic development. many classes of compounds, including organophosphorus pesticides, are able to cause oxidative stress that affects the delicate cellular redox balance regulating tissue modeling. we determined the progression of antioxidant defenses during the embryonic development of the south american common toad, bufo arenarum. superoxide dismutase (sod) and catalase (cat) activities were high in the unfertilize ... | 2008 | 18752312 |
| distribution pattern of neuropeptide y in the brain, pituitary and olfactory system during the larval development of the toad rhinella arenarum (amphibia: anura). | the first npy-immunoreactivity (ir) in the central nervous system of rhinella arenarum was obtained just after hatching in the pre-optic area, ventral thalamus and rostral rhombencephalon. during pre-metamorphosis, new npy-ir cells were observed in other brain areas such as pallium, septum and striatum, infundibulum and pars intermedia of the pituitary. further maturation continued through pro-metamorphosis with the appearance of cell groups in the diagonal band, amygdala, pre-optic nucleus, dor ... | 2009 | 19007358 |
| comparative diabetogenic action of the hypophysis from various animals. | of all the anterior hypophyses tested, those of the human produced the most marked diabetogenic action in the dog with its pancreatic tissue reduced to 4 gm., and in the hypophysectomized and pancreatectomized toad. the human hypophysis also produced diabetogenic action in the normal dog on daily doses of 1.26 mg. per kilo per day for 2 days. the hypophysectomized dog with its pancreas reduced to 4 gm. is very sensitive to the anterior hypophyseal diabetogenic action and is the best test animal ... | 1942 | 19871171 |
| vitellogenesis in bufo arenarum: identification, characterization and immunolocalization of high molecular mass lipovitellin during oogenesis. | vitellogenin (vtg), a large lipoglycophosphoprotein, is the most important precursor of the yolk proteins, and the major source of nutrients for the developing embryo in oviparous species. after its uptake by the oocytes, vtg is converted into lipovitellins (high and light) and phosvitin, which are deposited into crystalline yolk platelets. we describe here the presence of two high molecular mass lipovitellin isoforms in bufo arenarum mature oocytes with masses of 113 and 100 kda, respectively. ... | 2010 | 19932187 |
| effects of azinphos methyl and carbaryl on rhinella arenarum larvae esterases and antioxidant enzymes. | organophosphate (op) and carbamate pesticides are anticholinesterasic agents also able to alter antioxidant defenses in different organisms. amphibian larvae are naturally exposed to these pesticides in their aquatic environments located within agricultural areas. we studied the effect of the carbamate carbaryl (cb) and the op azinphos methyl (am), compounds extensively used in northern patagonian agricultural areas, on reduced glutathione (gsh) levels and the activities of esterases and antioxi ... | 2011 | 20709623 |
| cloning and sequence analysis of bufo arenarum oviductin cdna and detection of its orthologous gene expression in the mouse female reproductive tract. | summarythe glycoprotein envelope surrounding the bufo arenarum egg exists in different functional forms. conversion between types involves proteolysis of specific envelope glycoproteins. when the egg is released from the ovary, the envelope cannot be penetrated by sperm. conversion to a penetrable state occurs during passage through the pars recta portion of the oviduct, where oviductin, a serine protease with trypsin-like substrate specificity, hydrolyzes two kinds of envelope glycoproteins: gp ... | 2010 | 20810007 |
| the integrin-binding motif rgds induces protein tyrosine phosphorylation without activation in bufo arenarum (amphibia) oocytes. | integrins are cell adhesion molecules that are thought to be involved in sperm-oocyte interaction. nevertheless, their function in mammalian fertilization is still controversial, as different species behave differently. in amphibians, their role is mainly supported by xenopus laevis studies, where rgds peptide induces oocyte activation. we recently provided evidence suggesting the presence and involvement of integrins in the interaction of the oocyte plasma membrane (pm) with sperm in the amphib ... | 2011 | 21339287 |
| participation of the 39-kda glycoprotein (gp39) of the vitelline envelope of bufo arenarum eggs in sperm-egg interaction. | summarythe acquisition of egg fertilizability in bufo arenarum takes place during the oviductal transit and during this process the extracellular coelomic envelope (ce) of the eggs is converted into the vitelline envelope (ve). it has been stated that one of the necessary events leading to a fertilizable state is the proteolytic cleavage of ce glycoproteins in the oviductal pars recta by oviductin, a serine protease. consequently, there is a marked increase in the relative quantity of glycoprote ... | 2011 | 21406139 |
| [trophic ecology in tadpoles of rhinella arenarum (anura: bufonidae) in agroecosystems and their possible implications for conservation]. | the progress of the agriculture border has led an important loss of natural habitats, with significant consequences for biodiversity. in this sense, the studies in anuran amphibian tadpoles inhabiting these environments are relevant, because the larval stage is a phase of population regulation. the aim of this study was to analyze the body condition and diet in rhinella arenarum, tadpoles, an anuran species widely distributed in south america and that inhabit agroecosystems. three sites were sam ... | 2012 | 23894945 |
| adenylic nucleotides and energy charge during the embryonic development of bufo arenarum. | the contents of atp, adp and amp were determined by hplc and adenylic energy charge (aec) was estimated during different stages of the embryonic development of bufo arenarum up to the tailbud stage. all the developmental stages studied showed a high atp content (about 1.04-1.48 nmol/emb.). the concentration of adp was low (0.025-0.041 nmol/emb.) but rose slightly at the neural tube stage. amp was undetectable before the tailbud stage. aec values were almost constant (about 0.987-0.992) throughou ... | 2011 | 3098495 |
| an intra-axonal protozoon in the spinal cord of the toad bufo arenarum (hensel). | | 2016 | 4973772 |
| different sensitivity to lithium ion during the segmentation of bufo arenarum eggs. | | 1976 | 415468 |
| angiotensin converting enzyme in the toad bufo arenarum. | angiotensin converting enzyme activity (acea) was determined in serum, kidney, whole skin and isolated epithelia homogenates of the south american toad bufo arenarum. acea was present in the tissues and serum of the toad. the activity was higher in the kidney, as compared to that of the whole skin or isolated epithelium. captopril, teprotide and edta, caused a significant decrease in the acea. possible physiological roles for the presence of acea in the toad are discussed. | 2002 | 2869873 |
| effects of low concentrations of ethanol on the embryonic development of bufo arenarum. | the effects of low concentrations of ethanol on embryos of bufo arenarum were studied. embryos maintained continuously (from stage 3 on) in 0.84-3.34 microm ethanol showed concentration dependent effects: delay in the development rate and on eclosion, loss of equilibrium, arrhythmic contractions, swimming in atypical positions and high death rate. at lower concentrations the anomalies were concentration independent. embryos treated continuously with 0.002 and 0.21 microm ethanol until stages 19, ... | 2008 | 2861045 |
| effect of cholesterol and phosphatidylcholine of different chain length on acrosome breakdown and fertilizing capacity of amphibian spermatozoa. | the effect of different lipids on the fertilizing capacity of bufo arenarum spermatozoa and on acrosome breakdown of leptodactylus chaquensis spermatozoa was studied. sonicated vesicles of egg yolk phosphatidylcholine (1 mm) were as effective as vesicles of egg yolk phosphatidylcholine:cholesterol (molar ratio 1:0.9) in inhibiting the fertilizing capacity of bufo arenarum spermatozoa. this suggests that cholesterol depletion from the spermatozoa was not the cause of the fertility loss. bufo aren ... | 2011 | 3147938 |
| the development of the vitelline envelope during bufo arenarum oogenesis. | | 2011 | 3131637 |
| basal and amiloride-induced short-circuit current across isolated toad skin (bufo arenarum). | we have previously demonstrated that amiloride (amil) addition to the isolated ventral pelvic (vpel) skin of bufo arenarum toad induces negative short-circuit current values, which are equivalent to the isotopically measured net chloride transport. in the present work, we found that exposure of various regions of toad skin to amil yielded different values of short-circuit current (ascc): negative ascc was found in the vpel and ventral pectoral skin, while those of the dorsal one were not differe ... | 2011 | 3141246 |
| oviducal pars recta as factor in fertilization properties and hormonal regulation in the toad bufo arenarum. | in this communication i have attempted to present an overview of some contributions to the understanding of the oviduct-egg interaction in amphibians. according to data from other authors, the vitelline envelope of the newly ovulated egg constitutes a barrier for the passage of spermatozoa. our results demonstrated that only after they have been affected by substances released by the first 1-3 cm of the oviduct (pars recta), is the envelope sensitive to spermlysins and the oocytes fertilizable. ... | 2011 | 3103380 |
| inhibition of stimulated osmotic water flow by fluphenazine, a calmodulin inhibitor, in the isolated toad skin. | the effects of fluphenazine, a phenothiazine calmodulin inhibitor, on the osmotic water flow (posm) across isolated skins of bufo arenarum toads were tested. fluphenazine inhibited the increase in posm induced by agents known to act through the cyclic amp system (oxytocin, db-camp, theophylline, kcl and isoproterenol). the inhibitory effect was faster and more intense when the drug was present in the epidermal bath, and persisted after rinsing the preparation for 100 min. our results indicate th ... | 2010 | 2861050 |
| behavioral and eeg patterns of the female toad bufo arenarum during artificial clasping. | | 2015 | 4628046 |
| evaluation of antimicrobial and antiviral activities of different venoms. | animals' venomous secretions or peptides obtained from those secretions are used in the development of new therapeutic agents. the aims of this study were to investigate antimicrobial and antiviral activity of four different venoms obtained from the frog named bufo arenarum and the snakes crotalus atrox, causus rhombeatus and naja melanoleuca. | 2016 | 26743517 |
| proteolysis of interleukin-2, interferon and immunoglobulin by venoms. | limited proteolysis by venoms was analysed by the cleaved peptide band(s) in sds-polyacrylamide gel electrophoresis. the venom from crotalus atrox degraded interferon, interleukin-2, igg, igm, and a crude form of acetyl cholinesterase but had no effect on iga. although the venom from androctonus australis did not exert appreciable proteolysis on any of the immunoglobulins it had potent proteolytic activities against interferon and interleukin-2. the venom from vespula maculifrons had only a mino ... | 1991 | 1724747 |
| health status of tadpoles and metamorphs of rhinella arenarum (anura, bufonidae) that inhabit agroecosystems and its implications for land use. | perturbations of water bodies near agricultural and livestock systems can affect embryonic and larval stages of anurans and negatively impact adult populations and structure of amphibian communities. this study is focused on early development of rhinella arenarum, for which body growth, abnormalities in the oral disc and genetic damage on erythrocytes were analyzed to establish the impact of agroecosystems on local populations of amphibians. tadpoles and metamorphs of r. arenarum were collected ... | 2015 | 25919343 |
| isolation and nucleotide sequence analysis of the of rhinella arenarum β-catenin: an mrna and protein expression study during the larval stages of the digestive tract development. | β-catenin interacts with several proteins mediating key biological processes, such as cadherin-mediated cell-cell adhesion as well as signal transduction. this work was done to establish the molecular basis and regulation of the formation pattern of cadherin/β-catenin-mediated adherens junctions, using an animal model of unknown gene sequence, the toad rhinella arenarum. a rhinella arenarum β-catenin homolog was isolated from larval tissue, their sequence compared and analyzed with those of eigh ... | 2012 | 23000021 |
| adverse effect of agroecosystem pond water on biological endpoints of common toad (rhinella arenarum) tadpoles. | chemical prroducts used in farming and wastes from livestock can contaminate pond water in agroecosystems due to runoff. amphibians using these ponds for breeding are probably exposed to pollutants, and serious consequences might be observed afterward at the population level. assessment biological endpoints of anuran to water quality give a realistic estimate of the probability of occurrence of adverse effects and provide an early warning signal. in this study, the ecotoxicity of agroecosystem p ... | 2016 | 27395360 |
| common toad rhinella arenarum (hensel, 1867) and its importance in assessing environmental health: test of micronuclei and nuclear abnormalities in erythrocytes. | anthropogenic activities may generate significant changes in the integrity of aquatic ecosystems, so long-term monitoring of populations that inhabit them is crucial. counting micronucleated erythrocytes (mn) and erythrocytic nuclear abnormalities (ena) in peripheral blood is a widely used method for detecting chromosomal damage due to chemical agents in the water. we analyzed mn and ena frequency in blood obtained from the common toad rhinella arenarum populations in sites with different degree ... | 2015 | 26293892 |
| induction of micronuclei and nuclear abnormalities in tadpoles of the common toad (rhinella arenarum) treated with the herbicides liberty® and glufosinate-ammonium. | the assessment of micronucleated erythrocytes (me) in blood represents a widely used method for the detection of chromosomal damage by chemical agents, such as herbicides that may occur as water contaminants. we investigated the changes in some circulating blood-cell parameters of tadpoles of the common toad (rhinella arenarum) that were exposed during 48 or 96 h to three sub-lethal concentrations (3.75, 7.5, and 15 mg/l) of a commercial formulation of a glufosinate-ammonium (gla)-based herbicid ... | 2014 | 24769302 |