Jindal M N, Shah U H, Patel V K, Kelkar V V
Arzneimittelforschung. 1975 Jan;25(1):52-5.
The effect of three recently introduced beta-adrenoceptor blockers practolol, USVC 6524 and Inpea was studied on various skeletal muscle preparations. Practoloo, USVC 6524 and Inpea produced a dose related inhibition of acetylcholine induced contractions of rectus abdominis muscle of frog. These drugs also blocked neuromuscular transmission when tested on in vitro rat phrenic nerve diaphragm preparation; the blockade was partially reversed by physotigmine, KCl and adrenaline and was potentiated by d-tubocurarine. In gastrocnemius sciatic muscle-nerve preparation only Inpea exhibited neuromuscular blocking activity, while practolol and USVC 6524 did not show any effect up to a dose of 10 mg/kg (intraarterially). The apparent discrepancies between the results of in vitro and in vivo experiments could not be adequately explained. It has been discussed that the neuromuscular blockade caused by presently investigated beta-adrenoceptor blocking agents is essentially due to curare-like activity and to a small extent may be due to local anaesthetic activity.
研究了最近引入的三种β-肾上腺素能受体阻滞剂——心得宁、USVC 6524和因培安，对各种骨骼肌制剂的作用。心得宁、USVC 6524和因培安对乙酰胆碱诱导的青蛙腹直肌收缩产生剂量相关的抑制作用。在体外大鼠膈神经膈肌制剂上进行测试时，这些药物也阻断神经肌肉传递；毒扁豆碱、氯化钾和肾上腺素可部分逆转这种阻断作用，而d-筒箭毒碱可增强这种作用。在腓肠肌坐骨神经肌肉制剂中，只有因培安表现出神经肌肉阻断活性，而心得宁和USVC 6524在剂量高达10mg/kg（动脉内给药）时未显示任何作用。体外和体内实验结果之间的明显差异无法得到充分解释。有人讨论过，目前所研究的β-肾上腺素能受体阻滞剂引起的神经肌肉阻断主要是由于箭毒样活性，在一定程度上可能是由于局部麻醉活性。
