Toad Bufo Regularis Research Articles

The Egyptian Toad (Bufo regularis Reuss) as bioindicator to environmental deterioration with heavy metal in El-Behera governorate

The Egyptian Toad (Bufo regularis Reuss) as bioindicator to environmental deterioration with heavy metal in El-Behera governorate

Localization of alpha 2,6-linked sialic acid residues in gastrointestinal tract compartments of some tetrapod’s representatives: Comparative histochemical study

Epithelial mucins composed mainly of glycoproteins and play a vital role as protective barrier against a variety of harmful molecules and microbial infection. Additionally sialic acids, like glycoproteins, are considered as a main component of epithelial mucins and play an important role in mucosal immunity. For example, alpha 2,6-linked galactose/N-acetyl-galactosamine (Gal/GalNAc) sialic acid residues can recognize and mask different biological sites in some intermolecular or intercellular interactions. In this study, the localization sites relationship between general mucins and alpha 2,6-linked Gal/GalNAc sialic acid residues in different compartments in gastrointestinal tract (GIT) of tetrapod representatives were investigated using lectin histochemistry. The toad (Bufo regularis), lizard (Trachylepis quinquetaeniata), pigeon (Columba livia domestica) and mouse (Mus musculus) were used as amphibian, reptilian, avian and mammalian representatives respectively. In general, the biodistribution sites of mucins are localized in most compartment sites and partially overlapped with the sites of sialic acid residues in some compartment in each animal representative. Additionally, the localization sites of both mucins and sialic acid in the GIT regions differ based on the tissue type in each tetrapod representative. The mucosa of oesophagus in the toad and lizard showed higher positive signal of general mucins compared with other tetrapod representatives. However, the mucosa of the oesophagus in the toad revealed a positive signal of sialic acid in the tubular glands only, whereas the lizard’s mucosa showed a positive signal of sialic acid in the goblet cells. Additionally, the pigeon’s oesophagus showed no localization of the sialic acid or mucins while, all layers of the mouse’s oesophagus showed a positive localization of the sialic acid residues. In the stomach, all stomach mucosa compartments in all representatives showed positive signal of mucins, while the gastric glands in the toad, pigeon (proventricular glands) and mouse showed signals of sialic acid residues localization but in different trends. While the lizard showed a localization of the sialic acid in the mucosal lamina propria only. Furthermore, the mucosa of the ileum showed positive signal of mucin in the goblet cells and some absorptive cells brush borders in all tetrapod animals. While a higher signal of the sialic acid residues in the absorptive cells but not the goblet cells in the case of the toad and mouse. While the lizard’s ileum showed a higher localization of sialic acid in the goblet cells only. Mucin localization in the rectum was similar to those in ileum. Specifically, the toad and lizard showed signals of the sialic acid residues in the goblet cells only, while the mouse’s rectum showed a higher signal of sialic acids in the absorptive cells and lamina propria but not in the goblet cells. The present study introduces important data about the biodistribution and localization profiles of general mucins and sialic acids residues in the GIT different compartments in each representative of tetrapoda animals. Further studies are needed to investigate the important role of sialic acid residues localization in different compartments of GIT mucosa.

THE ROLE OF ADRENERGIC RECEPTORS IN THE ACTION OF ADRENALINE ON PLASMA LACTATE, GLUCOSE, LIVER, AND SKELETAL MUSCLE GLYCOGEN IN THE COMMON AFRICAN TOAD BUFO REGULARIS

In mammals, the roles of liver and skeletal muscle glycogen in adrenaline-induced hyperglycaemia are well known. However, in amphibians, there is limited information on the relative contribution of liver and skeletal muscle glycogen in adrenaline-induced hyperglycaemia. This study investigated the effects of adrenaline on blood glucose, plasma lactate, liverand skeletal muscle glycogen and the role of adrenergic receptors in the common African toad, bufo regularis. One hundred and twenty-five adult common African toads (70-100g) of both sexes were randomly collected and used in the study.Blood samples were collected from truncus arteriosus to estimate glucose and lactate levels. Blood glucose was determined immediately by modified glucose oxidase method. Plasma lactate was determined by modification of the Barker-Summerson method. Liver and gastrocnemius muscle glycogen were determined using anthrone reagents method. Adrenaline caused significant increase in blood glucose, lactate levels and significant reduction in liver and muscle glycogen. When toads were pre-treated with propranolol or prazosin, adrenalines reduction in liver and muscle glycogen was significantly reduced while the increase in blood glucose and lactate levels was prevented. Combination of both blockers abolished the increase in blood glucose, lactate levels and blocked reduction in liver and muscle glycogen produced by adrenaline. The results of this study showed that adrenalinecaused liver and skeletal muscle glycogen breakdown, increase in plasma lactate levels which resulted in hyperglycaemia in the common African toad bufo regularis. The study also showed that both alpha- and beta-adrenergic receptors are involved in mediating the effects of adrenaline on blood glucose, plasma lactate, liver, and muscle glycogenolysis and gluconeogenesis.

Effects of sodium metavanadate on the electrical stimulation of sciatic nerve of toads (Bufo regularis)

Introduction: Vanadium and its compounds have been documented to exert toxic effects on almost all systems in living organisms including cardiovascular, reproductive and nervous systems. In the nervous system however, toxicity assays have been on the brain and its structures with little information on its effects on peripheral nerves. This study was therefore conducted to examine the toxicity of vanadium in the peripheral nervous system. Methods: Vanadium as sodium metavanadate was used in the study. Fifteen toads (Bufo regularis) were randomly distributed into 3 groups (A-C); A served as control and was administered distilled water during the experiment, B were intraperitoneally (i.p.) administered with sodium metavanadate at 3 mg/kg while C were administered with sodium metavanadate at 5 mg/kg i.p. for 7 consecutive days. Nerve conduction was studied in isolated toad sciatic nerve-gastrocnemius muscle preparation following electrical stimulation. The recordings were obtained on a kymograph for each group. Results: The results showed significant (p<0.05) reduction in the peak amplitude of the action potential and an increase in the latency of the onset of the action potential at 5 mg/kg sodium metavanadate. Furthermore, an increased threshold stimulus voltage was also observed in group administered with 5 mg/kg sodium metavanadate. The values of these parameters in the 3 mg/kg sodium metavanadate group were not statistically different from the control group. Significance: The findings of this preliminary study suggest that vanadium at 5 mg/kg may result in decrease speed of impulse conduction which may be as a result of demyelination in the sciatic nerve.

Effect of thyroxine and carbimazole treatments on basal and histamine stimulated gastric acid secretion in the common African Toad (Bufo regularis).

Effect of thyroxine and carbimazole treatments on basal and histamine stimulated gastric acid secretion in the common African Toad (Bufo regularis).

Gastrointestinal parasites of common African toad (<i>Bufo regularis</i>) in Umuahia South, Abia State, Nigeria

Information on the parasites of common African toads ( Bufo regularis ) is still limited, judging by the global efforts to conserve amphibians. This informed the decision to provide baseline data of the gastrointestinal parasites of B. regularis of Umuahia South Local Area (LGA) of Abia State, Nigeria. Using standard methods, 321 B. regularis comprised of males, n =145, 45.17% and females n =176, 54.83% were collected from five communities (Old Umuahia, Amakama, Okwu, Ubakala and Agbama) in Umuahia South LGA, between June and November 2014. They were later examined for gastrointestinal parasites using standard procedures. Data analysis revealed that male B. regularis had more (n = 61, 19.03%) gastrointestinal parasites than the females (n = 58, 18.69%). Different species of gastrointestinal parasites belonging to class Cestoda ( Osphiotaenia nigriocollis, Lanfrediella sp and Proteocephalid Cestode larva ); Trematoda ( Messoceolium monody and Echinostoma revolutum ), Nematoda ( Amplicaecum africanum, Rhabdias bufonis, Ascaridoid, Oswaldocruzia pipiens and Camallanus sp ) and Protozoa ( Nyctotheroides bambuiensis, Lankesterellla bufonis and Protoopolina sp ) were identified with prevalence 20.25%, 4.36%, 7.48% and 4.98%, respectively. Prevalence of parasites varied significantly (p<0.05) across the gastrointestinal regions. Though no symptom of disease condition was established in all the B. regularis examined, high presence of gastrointestinal parasites could pose a threat to their existence. Keywords : Bufo regularis; cestoda; gastrointestinal parasitism.

Retina damage after exposure to UVA radiation on the early developmental stages of the Egyptian toad Bufo regularis Reuss

The present study was carried out to investigate the histological and histochemical changes in the retina on different developmental stages of Egyptian toad Bufo regularis. Our experiment started when tadpoles begin to feed. The adapted embryos are divided into 3 large tanks of 200 embryos each, collections of samples started from feeding age every three days. Both histological and histochemical results showed that the general architecture of the retina organ is correlated with the state of development. Therefore, it displayed different characteristic features depending on the investigated developmental stage starting from the larval stage (feeding began, stage 44) and ending with the post-metamorphic stage 66. Also, the present work aimed to study the chronic effects of UVA on the retina structure of B. regularis during development and metamorphosis for the first time.

Histological and Histochemical Studies on the Early Developmental Stages of the Egyptian Toad &amp;lt;i&amp;gt;Bufo regularis&amp;lt;/i&amp;gt; Reuss

The present study was carried out to investigate the histological and histochemical changes in the liver and skin on different developmental stages of Egyptian toad Bufo regularis to be used as a histological key for such species. Our experiment started when tadpoles began to feed. The adapted embryos are divided into 3 large tanks of 200 embryos each, collections of samples started from feeding age every three days. Both histological and histochemical results showed that the general architecture of the different organs was correlated with the state of development, i.e. larval, met-amorphic and post-metamorphic. They, therefore, displayed different characteristic features de-pending on the investigated developmental stage starting from the larval stage (stage 44) and ending with the post-metamorphic stage 66.

English

The role of adrenergic receptors in nicotine-induced hyperglycaemia has not been well studied in amphibians. Thus, this study investigates the effects of alpha and beta adrenergic receptor blockers in nicotine-induced hyperglycaemia in the common African toad Bufo regularis. Toads fasted for 24 h were anaesthetized with sodium pentobarbitone (3 mg/100 g body weight) intraperitoneally (i.p) and given intravenous (i.v) injection of 0.7% amphibian saline, or nicotine (50 &micro;g/kg), nicotine(50 &micro;g/kg i.v) 30 min after pretreatment with prazosin (0.2 mg/kg i.v), propranolol (0.5 mg/kg i.v) or combination of both prazosin (0.2 mg/kg i.v) and propranolol (0.5 mg/kg, i.v). Thereafter, blood samples were also collected from truncus arteriosus for estimation of blood glucose level using the modified glucose oxidase method. Nicotine caused significant increase (P&lt;0.01) in the levels of blood glucose in the common African toad. Pre-treatment of the toads with prazosin (0.2 mg/kg i.v) or propranolol (0.5 mg/kg, i.v) significantly (p &lt; 0.01) reduced the hyperglycaemia induced by nicotine (50 &micro;g/kg i.v). However, the combination of prazosin (0.2 mg/kg i.v) and propranolol (0.5 mg/kg, i.v) abolished the hyperglycaemic effect of nicotine (50 &micro;g/kg i.v). The above results on glucose metabolism suggests involvement of both alpha and beta adrenoceptors in nicotine-induced hyperglycaemia in common African toad B. regularis. &nbsp; Key words: Nicotine, hyperglycaemia, prazosin, propranolol, common African toad Bufo regularis.

Molecular Characterization on the Early Developmental Stages of the Egyptian Toad &lt;i&gt;Bufo regularis&lt;/i&gt; Reuss

The present study aimed to investigate changes in the protein contents using SDS-PAGE, also using the random amplified polymorphic DNA (RAPD-PCR) assay to identify changes in DNA concentration in the embryos of Egyptian toad Bufo regularis. Our experiment started when tadpoles began to feed. The adapted embryos were divided into 3 large tanks of 200 embryos each, collections of samples started from feeding age every three days. Cluster method was used to indicate the distinct distance between the band patterns of different stages. An increase occurred in the concentration of protein fractions in these tadpoles upon metamorphosis and that when metamorphosis was completed. DNA concentration exhibited an evident low values at the premetamorphic stage 44 (105.85 ± 0.519 ng/μl) compared with the other more advanced developmental stages 55 and 56 (204.056 ± 0.651 ng/μl and 234.55 ± 2.325 ng/μl respectively). In conclusion, acquire information about the changes in the molecular content of Bufo regularis during metamorphosis has been estimated.

The role of alpha and beta adrenergic receptors in cortisol-induced hyperglycaemia in the common African toad (Bufo regularis)

The role of adrenergic receptors in cortisol-induced hyperglycaemia is not well known. The present study investigated the effects of adrenergic receptor blockers in cortisol-induced hyperglycaemia in the common African toad (Bufo regularis). Each toad was fasted and anesthetized with sodium pentobarbitone (3 mg/100 g i.p). The animals (control) received intravenous (i.v) injection of 0.7% amphibian saline while animals (untreated) were given cortisol (20 µg/kg). In pre-treatment groups, animals received prazosin (0.2 mg/kg i.v), propranolol 0.5 mg/kg or combination of prazosin (0.2 mg/kg i.v) and propranolol (0.5 mg/kg i.v) before i.v injection of cortisol (20 µg/kg). Thereafter, blood samples were collected for estimation of blood glucose level using the modified glucose oxidase method. Cortisol caused significant increase in blood glucose level from 44.4±3.8 to 71.7±9.7 mg/dl. Pre-treatment of the toads with propranolol (0.5 mg/kg i.v) caused significant reduction (p≤ 0.01) in cortisol-induced hyperglycaemia while pre-treatment with prazosin (0.2 mg/kg i.v) produced no significant effect on hyperglycaemia induced by cortisol. The combination of both prazosin and propranolol completely abolished the effects of cortisol on blood glucose level. The results suggest that cortisol-induced hyperglycaemia in the toad (B. regularis) is mediated probably by both the α- and β-adrenergic receptors with the beta adrenergic receptors playing dominant role. Key words: Cortisol, hyperglycaemia, prazosin, propranolol, amphibian saline, common African toad.

Effect of gibberellin-A3 on metamorphosis in the Egyptian toad Bufo regularis

The present study was carried out to study the effect of gibberellin-A3 on the metamorphosis of the Egyptian toad Bufo regularis. Samples of B. regularis were collected from Shebin El-Kom, Menoufia Governorate during the breeding season and kept in aquaria with little water till spawning, fertilized eggs are divided into 2 groups of 200 eggs each. The 1st group was treated with 5ppm of gibberellin-A3 (Berelex) 3days/week for the period of metamorphosis. The second group was left untreated under the same environmental conditions and considered as a control. Hatchability of the eggs in each group was recorded. External lengths of the total body, hind limbs and the tail were measured. As a measure of apoptotic DNA fragmentation, the presence of DNA ladder was determined. The results showed that out of 200 eggs 47.5% were hatched in the control group and 76.5% were hatched in gibberellin-A3 treated group. The average duration of metamorphosis was 60days and 52days in the control and treated groups, respectively. There was an increase in the total length of the hind limbs of the treated tadpole as compared with the control throughout the experimental periods. DNA isolated from control and tadpoles treated with gibberellin-A3 showed degradation into oligonucleotide fragments forming a clear laddering pattern of apoptosis, but the treated tadpoles showed an increase of DNA fragmentation.

Chloromyxum aegypticus n. sp. (Myxozoa: Chloromyxidae) infecting the testicular tissue of the Egyptian toad, Bufo regularis (Amphibia: Bufonidae), and its pathogenicity

A new myxosporean, Chloromyxum aegypticus n. sp., is described from the testes of the Egyptian toad Bufo regularis, captured from El Mansoura locality. C. aegypticus is identified on the basis of cytology, electron microscopy and histopathology. It is distinguished from all previously reported Chloromyxum spp. by its shape, dimensions of the mature spore (9.1 ± 0.1 (9.0-9.2) μm in length × 7.9 ± 0.1 (7.8-8.0) μm in width), polar capsules, external ridge, sporoplasm nuclei, undulating suture, locality and host. Accumulation of several hundreds of plasmodia (0.8 ± 0.3 (0.5-1.1) mm in length × 0.5 ± 0.3 (0.2-0.7) mm in width) in the testes causes their enlargement. Parasites cause destruction of the seminiferous tubule cells and complete loss of spermatozoa. Since spermatogenesis stops, this seems to be a form of "parasitic castration". This is the first known record of the genus Chloromyxum in amphibian testes.

Hexamethonium produces both twitch and tetanic depression without fade in common African toad (&lt;i&gt;Bufo regularis&lt;/i&gt;)

The study was designed to investigate the nature of the cholinoceptors at the sciatic nerve-gastrocnemius muscle junction of the common African toad (Bufo regularis). Using myographic technique, the twitch properties of the sciatic-gastrocnemius muscle preparation of the common African toad was studied. Both the twitch height and peak tetanic height were measured as a percentage of control. Hexamethonium at a concentration of 0.1 mM significantly [P<0.05] reduced the mean twitch height from 2.62 cm to 1.0 cm and mean peak tetanic height from 5.38 cm to 4.32 cm. Hexamethonium, however does not produce tetanic fade at the same concentration. We hypothesized that the cholinoceptors of the neuromuscular junction of the common African toad (Bufo regularis) resemble the developing synapse of African clawed toad (Xenopus laevis) and may contain muscarinic M1 autoreceptors at the pre juntional membrane.

Hepatotoxicity Induced by Antifungal Drug Fluconazole in the Toads (Bufo Regularis)

Fluconazole is a triazole antifungal agent used for the treatment of certain superficial and systemic infections which predominantly affect immunocompromised individuals. Neoplastic lesions (hepatocellular carcinoma) were induced in the liver in 8 of 100 experimental toads (Bufo regularis) force fed with fluconazole, at a dose level of 0.26 mg /toad every day. Maximum time of exposure and observation was 20 weeks. In addition to the liver tumors, metastatic deposits from liver mass and other histopathological changes in liver were recorded. Collectively, these results confirm the hepatotoxic effect of fluconazole.

Histopathological Alterations in the Liver and Kidney of Toads (Bufo regularis) Intoxicated with a Pyrethroid Insecticide

Histopathological Alterations in the Liver and Kidney of Toads (Bufo regularis) Intoxicated with a Pyrethroid Insecticide

Effect of Acute Zinc Administration on Essential Metal Levels in Liver, Kidney, Lung and Heart of the Male Egyptian Toad Bufo Regularis

Effect of Acute Zinc Administration on Essential Metal Levels in Liver, Kidney, Lung and Heart of the Male Egyptian Toad Bufo Regularis

The Use of Swiss Albino Mice and Egyptian Toads (Bufo regularis) as Reliable Biological Test Animals for Screening Chemicals and Drugs Which Induce Leukaemia in Man. I: The Effect of Nizoral (Ketoconazole) on Leucocytes of Toads and Mice

The Use of Swiss Albino Mice and Egyptian Toads (Bufo regularis) as Reliable Biological Test Animals for Screening Chemicals and Drugs Which Induce Leukaemia in Man. I: The Effect of Nizoral (Ketoconazole) on Leucocytes of Toads and Mice

The use of toads (Bufo regularis) in a new biological assay for screening chemicals or drugs which induce leukaemia in man

Injection of Egyptian toads Bufo regularis, with adriamycin subcutaneously in the dorsal lymph sac at a dose level of 0.1 mg/toad, once every 3 weeks for 3 months induced pronounced alterations in the blood cells. These alterations were more or less similar to the criteria reported in human leukaemia. These changes were all comparable to those observed after the treatment of the experimental animals with the chemical carcinogen 7,12-dimethylbenz(a)anthracene. It is speculated that toads (Bufo regularis) can be used as biological test animals for screening chemicals or drugs which induce leukaemia in man.

Different temperature relations of two species of toads that coexist at the border of their geographical distributions

AbstractTemperature relations of two species of toads (Bufo viridis and Bufo regularis) that overlap at the border of their geographical distributions were studied in the laboratory in temperatures between 25°C and 2°C. Bufo regularis, a tropical species, could not survive at low temperatures that eventually led to its death in 1-2 days. The two species did not differ in their cooling and heating rates. At temperatures below 8-10°C, Bufo viridis maintained a body temperature that was higher than ambient by 1-2°C, while body temperature of Bufo regularis equaled that of the environment. In Bufo regularis heart beats ceased at low temperatures (&lt; 4°C), whereas in Bufo viridis at the same temperature, a rate of 6-9 beats/min was sustained. Our experiments suggest that Bufo viridis is endowed with particular capacities that allow it to remain active at low temperatures, while in Bufo regularis, a temperature-sensitive central mechanism seems to be damaged at low temperature. The ability of Bufo viridis to endure low temperatures and to remain active in this condition is specific to the species, and is not related directly to the immediate ecological situation of the animal.