Chiou L C, Chang C C
Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Republic of China.
J Pharm Pharmacol. 1988 Feb;40(2):148-9. doi: 10.1111/j.2042-7158.1988.tb05205.x.
The indirect twitch response of the mouse isolated phrenic nerve-diaphragm preparation, partially paralysed by tubocurarine, was restored only by about 10% by Ro 20-1724 at 2 to 280 microM. The solvent vehicle, dimethylsulphoxide, also showed the same effect to a similar extent. Intracellular recordings with glass microelectrodes revealed that Ro 20-1724 (40 microM) affected neither the resting membrane potential, the amplitude and frequency of miniature endplate potentials nor the amplitude of nerve-impulse evoked endplate potentials recorded in curarized preparations. The result indicates that Ro 20-1724 at a concentration four times the IC50 of phosphodiesterase inhibition has no effect on the quantal release of acetylcholine from a mammalian motor nerve and suggests that cAMP has no modulatory effect on the transmitter release.
用筒箭毒碱使小鼠离体膈神经 - 膈肌标本部分麻痹后，在2至280微摩尔浓度下，Ro 20 - 1724仅使间接抽搐反应恢复了约10%。溶剂二甲基亚砜在相似程度上也显示出相同的效果。用玻璃微电极进行的细胞内记录表明，Ro 20 - 1724（40微摩尔）对箭毒化标本中记录的静息膜电位、微小终板电位的幅度和频率以及神经冲动诱发的终板电位的幅度均无影响。结果表明，浓度为磷酸二酯酶抑制IC50四倍的Ro 20 - 1724对哺乳动物运动神经乙酰胆碱的量子释放没有影响，并提示环磷酸腺苷对递质释放没有调节作用。
