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Toad
About: Toad is a research topic. Over the lifetime, 1624 publications have been published within this topic receiving 28732 citations.
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TL;DR: In this paper , the influence of weather conditions and lunar phase on toad activity during the non-breeding season (April-November) was investigated, and the results on sexual differences in weather-mediated activity and lack of the lunar phase effects during non breeding season provided useful information for our understanding of life history of these toads.
Abstract: Abstract: Lunar phase and weather conditions are known to affect breeding activity of the Japanese common toad, Bufo japonicus formosus. However, information on toad activity during non-breeding season is very scarce. In this study, we investigated the influence of weather conditions and lunar phase on toad activity during the non-breeding season (April-November). Surface activity during the non-breeding season was monitored in Minami-ohsawa, Hachioji Tokyo from 2010 to 2014. The effects of weather conditions and the lunar phase on the number of toads captured were analyzed using Random Forests models (an ensemble machine learning method). Toads began to forage on the soil surface from late April and activity lasted until mid-November. Some meteorological variables such as temperature, wind, and atmospheric pressure affected toad activity, but the lunar phase, which is the most important variable in breeding activity, did not have an effect on surface activity of the toads during non-breeding season. However, differences were observed among adult males and females with respect to their response to meteorological variables: males responded positively to rainfall, but females did not. A distinct difference in the effect of temperature was also observed between adults and juveniles: juveniles became more active when daily minimum temperature was >15°C, although adults did not respond to an increase in temperature. Our results on sexual differences in weather-mediated activity and lack of the lunar phase effects during non-breeding season provide useful information for our understanding of life history of these toads.
TL;DR: In this paper , the effects of adrenaline on blood glucose, plasma lactate, liver and skeletal muscle glycogen and the role of adrenergic receptors in the common African toad, bufo regularis were investigated.
Abstract: 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.
TL;DR: It is reported that the parotoid gland secretion increased the force of contraction, heart beat and cardiac output in perfused frog’s heart, whereas, there was no change on hypodynamic heart, indicating that there may be existence of two components, one with β–receptor stimulating activity and other acting directly on the heart (independent of β1-adrenoreceptors).
Abstract: The present investigation has been undertaken to study the cardiotonic activity of parotoid gland secretion of common Indian Toad Bufo melanostictus on isolated perfused frog heart (Rana tigrina). Cardiotonic activity of parotoid gland secretion of B. melanostictus in normal as well as when induced with paraoxon (an organophosphate) was studied. For the evaluation of cardiotonic activity, Syme’s technique is being employed, digoxin and propranolol were used as standard drug and β-blocker respectively to characterize the effects on the receptors. The isolated perfused frog heart and hypodynamic frog heart showed dose dependent positive ionotrophic effects. The parotoid gland secretion exihibited cardiac stimulant activities. The propranolol was not able to block the effects of paraoxon induction on toad secretion. Thus, the present investigation reports that the parotoid gland secretion increased the force of contraction, heart beat and cardiac output in perfused frog’s heart, whereas, there was no change on hypodynamic heart, indicating that there may be existence of two components, one with β–receptor stimulating activity and other acting directly on the heart (independent of β1-adrenoreceptors).