Ribeiro J A, Dominguez M L, Gonçalves M J
Arch Int Pharmacodyn Ther. 1979 Apr;238(2):206-19.
Interactions between some substances (theophylline, noradrenaline, imidazole, ouabain and verapamil) and adenosine or adenosine triphosphate (ATP) were examined by recording the twitch tension of partially magnesium blocked phrenic-rat diaphragm preparations stimulated indirectly. Theophylline (an inhibitor of phosphodieterases) prevented and reversed the neuromuscular depression induced either by adenosine or ATP, and these substances antagonized the neuromuscular facilitation caused by imidazole (an activator of phosphodiesterases); noradrenaline and ouabain did not modify and verapamil increased that depression. These results indicate that the putative purine presynaptic receptor is not the ATPase, that it does not appear to operate by implication of cyclic AMP, but that it could mediate a process involved in the reduction of transmitter release by regulating the entry of calcium that follows the depolorization of the motor nerve endings.
通过记录部分镁阻断的膈-大鼠膈肌标本间接刺激后的抽搐张力，研究了某些物质（茶碱、去甲肾上腺素、咪唑、哇巴因和维拉帕米）与腺苷或三磷酸腺苷（ATP）之间的相互作用。茶碱（一种磷酸二酯酶抑制剂）可预防并逆转由腺苷或ATP诱导的神经肌肉抑制，且这些物质拮抗了由咪唑（一种磷酸二酯酶激活剂）引起的神经肌肉易化；去甲肾上腺素和哇巴因未产生影响，而维拉帕米增强了这种抑制。这些结果表明，假定的嘌呤突触前受体不是ATP酶，其似乎不是通过环磷酸腺苷起作用，而是可能通过调节运动神经末梢去极化后钙的内流来介导参与递质释放减少的过程。
