Severini C, Tita B, Bolle P
Institute of Neurobiology, CNR, Rome, Italy.
Arch Int Pharmacodyn Ther. 1992 May-Jun;317:56-66.
Extracts of the skin of the Australian myobatrachid frog Pseudophryne coriacea (PS) displayed striking, reversible and, in part, dose-dependent effects on the systemic blood pressure and the heart of the rabbit. Similarly to the results obtained in the rat, the blood pressure response in the rabbit consisted in an initial short-lasting fall, followed by a significant and persistent rise. The initial hypotensive effect was inhibited by atropine, indicating a cholinergic mechanism. The inhibition of the pressure rise by prazosin or guanethidine, but not by surrenalectomy or hexamethonium, suggests a catecholamine release from adrenergic nerve terminals of the vasculature. PS produced on the heart a variety of rhythm disorders, caused both by a release of acetylcholine and a direct effect on the myocardium. It is worth mentioning that tetrodotoxin, a typical sodium channel blocker, reduced or abolished the effects of PS both on the heart and the blood pressure, suggesting that sodium channels may directly or indirectly participate in the mechanism of action of PS.
澳大利亚沼蟾科蛙类——粗皮伪蛙（Pseudophryne coriacea，简称PS）皮肤提取物对家兔的全身血压和心脏呈现出显著、可逆且部分呈剂量依赖性的效应。与在大鼠身上获得的结果相似，家兔的血压反应先是出现短暂的下降，随后显著且持续升高。阿托品可抑制最初的降压效应，表明存在胆碱能机制。哌唑嗪或胍乙啶可抑制血压升高，但肾上腺切除术或六甲铵则无此作用，这表明血管的肾上腺素能神经末梢释放了儿茶酚胺。PS可使心脏产生多种节律紊乱，这是由乙酰胆碱释放和对心肌的直接作用共同引起的。值得一提的是，典型的钠通道阻滞剂河豚毒素可减弱或消除PS对心脏和血压的作用，这表明钠通道可能直接或间接参与了PS的作用机制。
