Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “TOADS”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 253 records · Page 14Linked to original sources
PubMed1986

Disk method for measuring effects of neurohypophysial hormones on urea permeability of toad bladder.

This study describes a precise and sensitive method for the bioassay of 8-arginine vasotocin (AVT). The technique is based on the observation that AVT increases the permeability to urea of the isolated toad bladder and that this effect can be measured with minute quantities of AVT by suspending bladders in humid air and applying hormone on small paper disks. The hormone diffuses from the disk to the underlying epithelium where it increases permeability to urea. The bladder is filled with Ringer's fluid containing [14C]urea and the label diffuses across the bladder wall into the disk at the serosal surface. Disks are removed at timed intervals for scintillation counting. Disks containing 0.25 pg AVT accumulated 232 +/- 8 cpm of [14C]urea in 30 min, whereas control disks without hormone at a distance of 3-4 mm on the same bladder wall accumulated only 12 +/- 2 cpm. The minimal sensitivity during the summer was 0.1 pg AVT. Average values (+/- SE) for induction of a half-maximal urea permeability response in toads from all seasons were 1.4 +/- 0.3 X 10(-10) M for AVT, 7.4 +/- 1.5 X 10(-9) M for 8-arginine vasopressin, and 2.9 +/- 0.6 X 10(-8) M for oxytocin. Plasma from a hydrated toad (255 mosm/kg H2O) showed AVT-like activity of 1.53 X 10(-11) M and from a dehydrated toad (342 mosm/kg H2O) 4.86 X 10(-11) M. Because this bioassay is specific and as sensitive as the radioimmunoassay, it may serve as a useful tool for studying the physiology of vasotocin.

Animals↗
PubMed1987

Effect of parathyroid hormone on transport by toad and turtle bladder.

We recently demonstrated that parathyroid hormone (PTH) inhibited both vasopressin- and cyclic AMP-stimulated water transport in the toad bladder. This was associated with an increase in calcium uptake by isolated epithelial cells. We postulated that PTH exerts its action on H2O transport by directly stimulating calcium uptake. The current study was designed to compare the effects of PTH and the calcium ionophore, A23187, on H2O and Na transport and H+ secretion in toad and turtle bladders. In toad bladder, PTH and A23187 decreased arginine vasopressin (AVP)-stimulated H2O flow and short-circuit current (SCC) after 60 min serosal incubation. In turtle bladder A23187 decreased SCC to 79.3 +/- 3.6% of base line (P less than 0.05), and significantly decreased RSCC as well. PTH had no effect on SCC or H+ secretion in turtle bladders. Both PTH and A23187 increased 45Ca uptake in toad bladder epithelial cells; only A23187 increased 45Ca uptake in the turtle bladder. The different action of PTH in these two membranes, compared with that of the calcium ionophore, illustrates the selectivity of PTH on membrane transport. PTH increases calcium uptake and decreases transport only in a hormone-sensitive epithelium, whereas the ionophore works in virtually all living membranes. The mode of action of these two agents to increase calcium uptake is, therefore, likely different.

Animals↗
PubMed1990

Effect of hematocrit on behavioral thermoregulation of the toad Bufo marinus.

This study tested the hypothesis that the oxygen capacity of blood, indexed by hematocrit, affects the body temperature (Tb) selected by toads (Bufo marinus) in a thermal gradient. Anesthetized toads (Brevital sodium; 40 mg/kg im) were fitted with a cloacal thermistor and femoral artery cannula. After recovery, they were placed in a thermal gradient ranging from approximately 10 to 40 degrees C. Tb was measured for 24 h. Then 1-2 ml blood were withdrawn and replaced with an equal volume of either 0.66% saline or packed red cells from donor toads. Selected Tb was measured for the next 24 h. The mean Tb selected by B. marinus (n = 33) was 24.9 degrees C. Cross-sectional analysis showed no correlation between selected Tb and hematocrit. However, each toad rendered anemic showed a reduction of selected Tb (mean = 22.9 degrees C). The degree of Tb reduction was correlated with the hematocrit reduction, (r = 0.86; P = 0.013). Blood doping did not have a significant effect on selected Tb. The reduction of Tb could be adaptive by reducing oxygen consumption.

Animals↗
PubMed1996

Heterogeneity and lability of endogenous digitalis-like substances in the plasma of the toad, Bufo marinus.

Three major groups of endogenous digitalis-like substances (EDLS) have been identified in the plasma of the toad, Bufo marinus. One group of compounds, present in fresh plasma, is composed of chromatographically homogeneous polar conjugates, principally bufadienolide 3-sulfates, which exhibit relatively weak Na(+)-K(+)-adenosinetriphosphatase (ATPase) inhibitory activity. A second and larger group of compounds, also found in fresh plasma, includes chromatographically heterogeneous conjugates, which are effective inhibitors of Na(+)-K(+)-ATPase; these compounds possess properties similar to those of bufotoxins. The third group of EDLS consists of free unconjugated bufadienolides, which are also effective Na(+)-K(+)-ATPase inhibitors. These unconjugated bufadienolides are present in relatively low concentrations in fresh toad plasma, but appreciable quantities are enzymatically generated from conjugates (believed to consist principally of bufotoxins) during the in vitro incubation of plasma. We suggest that the extent to which circulating polar EDLS are enzymatically deconjugated in vivo may be important in the regulation of the digitalis-sensitive Na(+)-K(+)-ATPase of toad brain, the only known digitalis-sensitive Na(+)-K(+)-ATPase in the toad.

Animals↗
PubMed1980

Effect of verapamil on the hydroosmotic response to antidiuretic hormone in toad urinary bladder.

To investigate the role of the calcium ion in the hydroosmotic response to antidiuretic hormone (ADH), the effects of verapamil, an inhibitor of calcium ion entry into cells, on stimulated water flow was examined in vitro in the toad urinary bladder. Verapamil, 50 micro M, decreased ADH-stimulated osmotic water flow from 23.4 +/- 4.1 to 9.9 +/- 3.3 mg . min-1 . hemibladder-1 (mean +/- SE, n = 12, P < 0.001). That this inhibitory effect was due to a verapamil-induced alteration in cellular calcium metabolism is suggested by the findings that 45Ca2+ uptake by isolated toad bladder epithelial cells was reduced nearly 50% in the presence of verapamil and that reversibility of verapamil's inhibitory action was calcium dependent. Additionally, verapamil reduced theophylline- (20 mM) stimulated water flow from 22.8 +/- 2.7 to 9.5 +/- 2.9 mg . min-1 . hemibladder-1 (n = 7, P < 0.001) but enhanced cAMP- (10 mM) induced water flow from 12.8 +/- 2.5 to 21.6 +/- 1.1 ng . min-1 . hemibladder-1 (n = 7, P < 0.001). The latter effect was due, at least in part, to a direct inhibitory effect by verapamil on phosphodiesterase activity of toad bladder homogenates. These results, therefore, suggest that the calcium ion is an important coupling factor at the level of the adenylate cyclase enzyme complex for the stimulus-reabsorption coupling between ADH and the transporting epithelia of the toad urinary bladder.

Animals↗
PubMed1984

Identification of actin-binding protein and villin in toad bladder epithelia.

Two actin-modulating proteins, actin-binding protein and villin, have been identified and functionally characterized in toad bladder epithelial cells. A 270-kdalton protein from bladder epithelial extracts 1) cross-reacts with antibodies to purified toad oocyte or rabbit macrophage actin-binding protein and comigrates with these proteins on gel electrophoresis, 2) contains all of the actin filament cross-linking activity found in epithelial cell extracts, and 3) its activity is calcium insensitive. A 95-kdalton protein from the same extracts 1) cross-reacts with antibodies to purified toad oocyte villin and comigrates with purified villin from the oocyte and chicken intestine on polyacrylamide gels, and 2) is capable of decreasing the viscosity of actin solutions only in the presence of calcium. These proteins offer potential sites for calcium-dependent and -independent regulation of toad bladder epithelial cell structure.

Animals↗
PubMed1989

Effect of carbenoxolone on glucocorticoid metabolism and Na transport in toad bladder.

In humans, diminished 11 beta-hydroxysteroid dehydrogenase (11 beta-OHSD) enzyme activity has been associated with sodium retention and hypertension. These studies show that the toad bladder, another target tissue epithelium displaying steroid-induced sodium transport, possesses the enzyme 11 beta-OHSD. The toad urinary bladder rapidly transformed corticosterone (3 x 10(-8) M) (50% by 10 min and 90% by 180 min) with 11-dehydrocorticosterone being the major metabolite. The 11-dehydrocorticosterone produced reached an apparent plateau when the tissue incubations were repeated with higher concentrations of corticosterone (10(-7) and 10(-6) M). Carbenoxolone sodium (2.5 x 10(-5) M), a water soluble derivative of glycyrrhetinic acid, markedly inhibited the metabolism of corticosterone (3 x 10(-8) M) to 11-dehydrocorticosterone similar to previous observations in the mammalian kidney. Carbenoxolone sodium (2.5 x 10(-5) M) did not significantly affect short-circuit current (SCC) in toad bladders when added to either the serosal or mucosal bath. However, when carbenoxolone sodium was added to the mucosal bath and 60 min later corticosterone 10(-6) M was placed in the serosal bath, bladders generated a SCC 2.07 +/- 0.17 (mean +/- SE) times above base line at 360 min compared with 1.48 +/- 0.11 in bladders exposed to corticosterone alone (P less than 0.02). In parallel experiments, carbenoxolone sodium in the mucosal bath enhanced the rise in SCC induced by cortisol 10(-6) M; 1.66 +/- 0.16 times above base line at 360 min compared with 1.07 +/- 0.14 with cortisol alone (P less than 0.02). We conclude that the toad bladder contains 11 beta-OHSD and inhibition of this enzyme with carbenoxolone sodium is associated with amplification of glucocorticoid-induced transepithelial sodium transport in this tissue. However, since the quantity of 11-dehydro-product produced appears to be limited, other factors in addition to inhibition of 11 beta-OHSD may play a role in this amplification of sodium transport.

Animals↗
PubMed1993

Activity of 11 beta-hydroxysteroid dehydrogenase in toad bladder: effects of 11-dehydrocorticosterone.

11 beta-Hydroxysteroid dehydrogenase (11 beta-OHSD) transforms circulating glucocorticoids to their "biologically inert" 11-dehydro derivatives. Isoforms of 11 beta-OHSD with different cofactor requirements and biochemical properties [Michaelis constant (Km) and maximal velocity (Vmax)] exist in the kidney. Since epithelial cells derived from the toad bladder also contain this enzyme, we wished to further characterize its properties in prepared cell homogenates. 11 beta-OHSD from toad bladder demonstrated a clear preference for NAD+ over NADP+ as a cofactor similar to that observed in renal cortical collecting duct (CCD) cells. Furthermore, 11 beta-OHSD had a rapid onset of action. The apparent Km for corticosterone was 16.3 x 10(-8) M, a value comparable to that observed for enzyme from CCD, and a Vmax of 4.8 x 10(-12) mol.mg protein-1.min-1. The end product, 11-dehydrocorticosterone (compound A), influenced enzyme activity; it increased 11 beta-OHSD activity at corticosterone concentrations below the apparent Km for the enzyme and inhibited 11 beta-OHSD activity at corticosterone concentrations above the Km for the enzyme. The inhibitory effects of compound A appeared noncompetitive with an apparent equilibrium constant (Ki) of 2.8 x 10(-7) M. Consistent with its inhibitory action on 11 beta-OHSD, compound A (10(-6) M) enhanced the short-circuit current response to corticosterone (10(-7) M) in the intact toad bladder (experimental 2.03 +/- 0.33 vs. control 1.40 +/- 0.17 times above baseline; n = 7, P < 0.01). Thus 11 beta-OHSD in toad bladder resembles the isoform found in CCD, and compound A may be biologically important as a regulator of 11 beta-OHSD.

11-beta-Hydroxysteroid Dehydrogenases↗
PubMed1996

Gonadotropin-releasing hormone neuroblasts from one olfactory placode can be present in both hemispheres in the clawed toad Xenopus laevis.

Ontogenetic differentiation of the GnRH-immunoreactive (GnRHir) neuron system was studied in the clawed toad Xenopus laevis by immunocytochemistry employing polyclonal antibodies against mammalian GnRH and chicken type II GnRH, and monoclonal antibodies against GnRH exhibiting wide cross-reactivity over animal classes. Toads at different stages of differentiation as well as postmetamorphic toads subjected to uni- or bilateral ablation of the olfactory placode (OPX) between developmental stages 25 and 30 were studied. GnRHir neurons and nerve fibers could not be detected before metamorphosis. Following metamorphosis, at stage 65-66, hemi-OPX toads did not exhibit any side differences in the number and overall distribution of the GnRHir neuronal structures; however, the total number of GnRHir neurons was approximately 50% of that counted in intact controls at the same developmental stages. These findings indicate that GnRHir neuroblasts differentiating on one side in the olfactory placode can appear on both sides of the brain in the course of their migration.

Animals↗
PubMed1985

Inhibition of vasopressin-stimulated water flow in toad bladder by phorbol myristate acetate, dioctanoylglycerol, and RHC-80267. Evidence for modulation of action of vasopressin by protein kinase C.

The action of vasopressin (AVP) in transporting epithelia is mediated by cyclic AMP(cAMP), whereas its effects in hepatocytes are mediated by calcium and phosphoinositides. Based on our recent observation that AVP stimulates phosphoinositide turnover in toad bladder, we examined the role of calcium-phospholipid-dependent kinase (protein kinase C) as a modulator of AVP's hydroosmotic effect. Phorbol myristate acetate (PMA), which can substitute for diglyceride as an activator of protein kinase C, the diglyceride dioctanoylglycerol, and RHC-80267, a glyceride lipase inhibitor that should increase diglyceride levels, inhibited AVP-stimulated water flow, but not water flow stimulated by cAMP, suggesting inhibition of cyclic AMP production. Both the dioctanoylglycerol and RHC-80267, but not PMA, also decreased water flow in response to 8-bromo cAMP indicating a potential inhibition at post-cAMP events as well. PMA increased prostaglandin synthesis; however, inhibition of water flow persisted even when prostaglandin synthesis was completely blocked by incubation with naproxen. Furthermore, water flow was not inhibited by incubation with the inactive diglyceride substitute phorbol didecanoate, supporting the specificity of the PMA inhibition. Consistent with the site of action at adenylate cyclase suggested by the transport experiments, PMA and RHC-80237 decreased both cell cAMP content and the cyclic AMP-dependent kinase ratio (-cAMP/+cAMP), an index of intracellular cyclic AMP effect. Assay for protein kinase C activity in toad bladder epithelial cell supernatant demonstrated that the toad bladder indeed contains a kinase stimulable by phospholipid, calcium, and PMA. As an apparently independent effect, we found that addition of PMA, but not dioctanoylglycerol or RHC-80267, to the mucosal bath increased both water permeability and the frequency of granular cell luminal membrane aggregates in the absence of vasopressin, consistent with stimulation of fusion events at the luminal membrane. Our data suggest that protein kinase C can modulate AVP-stimulated water flow in toad bladder by inhibiting cAMP generation, and perhaps post-cAMP steps as well, and support the hypothesis that AVP-stimulated turnover of membrane phosphoinositides antagonize the effects of AVP via changes in diglyceride, calcium, and protein kinase C.

Animals↗
PubMed2006

Progesterone improves the number and quality of hormone induced Fowler toad (Bufo fowleri) oocytes.

Combinations of progesterone, lutenizing hormone releasing hormone analogue (LHRHa), human chorionic gonadotrophin (hCG), and the dopamine-2 (DA2) receptor antagonist 1-[1-[4,4-bis(4-Fluorophenyl)butyl]-4-piperidinyl]-1,3-dihydro-2H-benzimidazol-2-one (Pimozide; Orap) were tested for improvement of spawning rates, oocyte numbers, fertilization and neurulation rates of the Fowler toad (Bufo fowleri). Only treatments combined with progesterone produced large numbers of oocytes. The best treatment on oocyte numbers, neurulation rates, and the number of neurulas was with 5 mg progesterone, 20 mic.g LHRHa, and 0.25 mg Pimozide. Progesterone (5 mg) with 60 mic.g LHRHa gave high spawning rates, oocyte numbers, and fertilization rates but neurulation rates were low. Progesterone alone in high repeated doses did not result in ovulation. High doses of LHRHa (60 mic.g) with hCG, progesterone, and Pimozide gave the greatest number of toads spawning, however, they resulted in low oocyte numbers, fertilization and neurulation rates. A low dose of LHRHa (4 mic.g) with hCG, or hCG alone as a second administration, and progesterone with Pimozide produced few good quality oocytes. Toads were given normal ovulatory doses of hormones 24 or 48 hrs after their initial dose, but these resulted in low oocyte numbers followed by poor fertilization. Overall, these results suggest that progesterone with a dose between 20 mic.g and 60 mic.g of LHRHa may be optimal for the induction of ovulation in these toads. Moreover, Pimozide can supplement low doses of LHRHa but not replace it.

Animals↗
PubMed2003

Cardiovascular responses to hypoxia and anaemia in the toad Bufo marinus.

Amphibians exhibit cardiorespiratory responses to hypoxia and, although several oxygen-sensitive chemoreceptor sites have been identified, the specific oxygen stimulus that triggers these responses remains controversial. This study investigates whether the cardiovascular response to oxygen shortage correlates with decreased oxygen partial pressure of arterial blood (Pa(O(2))) or reduced oxygen concentration ([O(2)]) in toads. Toads, equipped with blood flow probes and an arterial catheter, were exposed to graded hypoxia [fraction of oxygen in the inspired air (FI(O(2)))=0.21, 0.15, 0.10, 0.07 and 0.05] before and after reductions in arterial [O(2)] by isovolemic anaemia that reduced haematocrit by approximately 50%. Toads responded to hypoxia by increasing heart rate (fH) and pulmocutaneous blood flow (Q(pc)) and reducing the net cardiac right-to-left-shunt. When arterial [O(2)] was reduced by anaemia, the toads exhibited a similar cardiovascular response to that observed in hypoxia. While arterial CO(2) partial pressure (Pa(CO(2))) decreased significantly during hypoxia, indicative of increased alveolar ventilation, anaemia did not alter Pa(CO(2))). This suggests that reductions in [O(2)] mediate cardiovascular adjustments, while ventilatory responses are caused by reduced Pa(O(2)).

Anemia↗
PubMed2006

Cardiovascular and behavioural changes during water absorption in toads, Bufo alvarius and Bufo marinus.

Blood cell flux (BCF) in the pelvic skin of Bufo marinus was lower than Bufo alvarius when toads rehydrated from deionised water (DI) or 50 mmol l-1 NaCl (NaCl). Despite the lower BCF in B. marinus, water absorption was not different between the species when toads rehydrated from DI or NaCl. When fluid contact was limited to the pelvic skin, water uptake from NaCl was lower than from DI, but became greater than uptake from DI as the immersion level increased. Hydrophobic beeswax coating the lateral sides reduced absorption from NaCl but not from DI. Toads settled into water absorption response posture well after maximal BCF was attained in both DI and NaCl, indicating that the behavioural response requires neural integration beyond the increase in BCF. Water exposure increased BCF in hydrated B. alvarius with empty bladders but not in those with stored bladder water. Hydrated B. marinus with an empty bladder did not increase BCF when given water. Handling stress depressed BCF but increased central arterial flow (CAF), measured using a flow probe around the dorsal aorta. In undisturbed toads, CAF increased with the same time course as BCF while heart rate remained relatively constant, suggesting redistribution of blood flow.

Animals↗
PubMed2006

Storage and recovery of elastic potential energy powers ballistic prey capture in toads.

Ballistic tongue projection in toads is a remarkably fast and powerful movement. The goals of this study were to: (1) quantify in vivo power output and activity of the depressor mandibulae muscles that are responsible for ballistic mouth opening, which powers tongue projection; (2) quantify the elastic properties of the depressor mandibulae muscles and their series connective tissues using in situ muscle stimulation and force-lever studies; and (3) develop and test an elastic recoil model, based on the observed elastic properties of the depressor mandibulae muscles and series connective tissues, that accounts for displacement, velocity, acceleration and power output during ballistic mouth opening in toads. The results demonstrate that the depressor mandibulae muscles of toads are active for up to 250 ms prior to mouth opening. During this time, strains of up to 21.4% muscle resting length (ML) develop in the muscles and series connective tissues. At maximum isometric force, series connective tissues develop strains up to 14% ML, and the muscle itself develops strains up to 17.5% ML. When the mouth opens rapidly, the peak instantaneous power output of the depressor mandibulae muscles and series connective tissues can reach 9600 W kg(-1). The results suggest that: (1) elastic recoil of muscle itself can contribute significantly to the power of ballistic movements; (2) strain in series elastic elements of the depressor mandibulae muscle is too large to be borne entirely by the cross bridges and the actin-myosin filament lattice; and (3) central nervous control of ballistic tongue projection in toads likely requires the specification of relatively few parameters.

Animals↗
PubMed1988

The aerobic cost of saltatory locomotion in the fowler's toad (Bufo woodhousei fowleri).

Studies of kangaroos suggest that hopping provides energy savings during locomotion at high speeds, although studies of small mammals suggest that hopping is no more economical than running. To obtain comparative data on anurans, we exercised Fowler's toads (Bufo woodhousei fowleri, 25.8 g) on treadmills at speeds ranging from 0.09 to 0.63 km h-1 while measuring oxygen consumption (VO2), endurance or hop kinematics. The toads walked at slow speeds and hopped at fast speeds. Steady-state VO2 (VO2,ss) increased linearly with speed to a maximum (VO2, max) of 1.17 ml O2 g-1 h-1 at 0.27 km h-1 and was nine times the average pre-exercise VO2. The maximum rate of oxygen consumption during treadmill exercise was comparable to VO2,max previously reported for less natural exercise regimes. At speeds greater than or equal to 0.27 km h-1, VO2,ss was independent of speed. At speeds less than or equal to 0.36 km h-1, toads moved for over 1h, but endurance decreased sharply at higher speeds. Hop rate, hop length, hop height and angle of take-off increased with speed. Hopping in B.w. fowleri was not less costly than running in other animals of similar body size and was inefficient at converting metabolic to mechanical energy. The present study suggests that hopping in toads, as in small mammals, is not economical during sustained locomotion and is most important during short bursts of high-intensity activity.

Animals↗
PubMed1994

IS WALKING COSTLY FOR ANURANS? THE ENERGETIC COST OF WALKING IN THE NORTHERN TOAD BUFO BOREAS HALOPHILUS

Locomotor mode and the maximal capacity for aerobic metabolism are thought to be co-adapted in anuran amphibians. Species that rely heavily on walking often have high capacities for aerobic metabolism relative to species that rely primarily on saltation. We tested the hypothesis of co-adaptation of gait and aerobic metabolism by investigating the locomotor energetics of Bufo boreas halophilus, a toad that walks, but does not hop. Rates of oxygen consumption during locomotion were measured in an enclosed variable-speed treadmill. The steady-state rate of oxygen consumption (V(dot)O2ss) increased linearly within a range of sustainable speeds [V(dot)O2ss (ml O2 g-1 h-1) = 0.93 x speed (km h-1) + 0.28]. The minimum cost of transport, Cmin (the slope of this relationship), varied significantly among individual toads. When expressed in units of oxygen consumed per distance travelled (ml O2 km-1), Cmin scaled isometrically with body mass: Cmin = 0.69mass1.07. Consequently, mass-specific Cmin (ml O2 g-1 km-1) was uncorrelated with body mass. Variation in Cmin was also unrelated to experimental temperature. Mass-specific Cmin estimates were similar to previous allometric predictions for terrestrial animals of similar size, which contrasts with previous findings for another toad species. Maximum rates of oxygen consumption measured in closed, rotating respirometers were significantly higher than the maximum rates achieved on the treadmill, but lower than those measured previously in other Bufo species. Our results indicate that walking is not necessarily a costly gait for toads and that high maximum rates of oxygen consumption are not associated with reliance on walking within the genus Bufo.

Journal Article↗
PubMed1975

[Phylogenetic studies on some Japanese amphibia by mean of immunoelectrophoresis. I. Relationships of some frogs and newt to toad (author's transl)].

The phylogenetic relationship among toad, frogs and newt from Japan was investigated by means of immunoelectrophoresis. Homologous, heterologous and non-identity reactions between rabbit anti-Bufo bufo antiserum and antigen from each of 13 species and 2 subspecies of Japanese amphibia were examined. The number and positions of arcs appeared in these reactions were compared. The relationship observed in the comparison well coincided with the classification of the upper taxa of amphibia; viz 1) Hyla arborea is more intimately related to B. bufa, 2) members of Ranidae and Rhacophoridae have equal intimacy for B. bufo, and 3) Cynops pyrrhogaster is most distantly related to B. bufo. By contrasting arc obtained in non-identity reaction and those obtained in homologous reaction, it was found that toad, B. bufo carried 22 antigens, and among these antigens, one was observed through all amphibians tested, 12 were carried solely by toad, and some of the remainders were common to antigens carried by various frogs. Newts carried only one antigen common to toad. Based on these results, the phylogeny of Japanese amphibia was discussed.

Amphibians↗
PubMed1995

Chemopreventive effects of cabbage on 7,12-dimethylbenz(a)-anthracene-induced hepatocarcinogenesis in toads (Bufo viridis).

Hepatocellular carcinoma was induced in the toad, Bufo viridis, in 29 out of 100 cases by the administration of 0.5 mg of 7,12-dimethylbenz(a)anthracene (DMBA)/toad, 3 times/week for 12 weeks. In contrast, toads treated with DMBA and cabbage diet 1 or 2 ml (3 h prior to the carcinogen)/toad, every day for 12 weeks showed a lower incidence of liver tumors: 15 and 12 cases out of 100. However, cabbage diet (2 ml/toad, every day for 12 weeks) was ineffective when administered 3 h after the carcinogen (DMBA) in 27 out of 100 cases. Neither tumor growth nor neoplastic changes were observed in toads treated with olive oil alone or with cabbage diet. It is concluded that a cabbage diet during initiation has an inhibitory effect on hepatocarcinogenesis in toads.

9,10-Dimethyl-1,2-benzanthracene↗