Chen J M, Zhang M Z, Gu S L, Zhang G Y
Department of Pharmacology, Xuzhou Medical College.
Yao Xue Xue Bao. 1993;28(4):246-50.
The calcium antagonistic actions of atropine (Atr) and verapamil (Ver) were studied on the contraction of rabbit thoracic aorta strips induced by CaCl2 and KCl. Both Atr and Ver were found to depress the contraction as demonstrated by the shift-to-right of the dose-effect relationship curves and the decrease of maximal responses, with the value of pD'2 being 4.4 and 5.8 respectively. The intracellular Ca(2+)-dependent component of NE-induced aortic strip contraction was also inhibited by the 2 drugs, but the extracellular Ca(2+)-dependent component was barely or not inhibited by Atr before its concentration was raised to 100 mumol/L. These results indicate that the depressive effect of Atr on aortic contraction is mainly exerted by acting on the PDC (potential-dependent channel). The action of Atr on proliferation of cells was also studied in rabbit aortic smooth muscle cell (ASMC) culture. The growth was inhibited by Atr when Ca2+ was present in the medium. When Ca2+ was absent, however, the growth was stimulated by Atr 20.6-185.2 mumol/L, but inhibited by Atr 555.7-1666.7 mumol/L, suggesting that Ca2+ is somehow involved in the action of Atr on ASMC growth.
研究了阿托品（Atr）和维拉帕米（Ver）对氯化钙和氯化钾诱导的兔胸主动脉条收缩的钙拮抗作用。发现Atr和Ver均能抑制收缩，表现为剂量-效应关系曲线右移和最大反应降低，pD'2值分别为4.4和5.8。这两种药物也抑制了去甲肾上腺素诱导的主动脉条收缩的细胞内钙依赖性成分，但在Atr浓度升高至100μmol/L之前，其对细胞外钙依赖性成分几乎没有抑制作用。这些结果表明，Atr对主动脉收缩的抑制作用主要是通过作用于电位依赖性通道（PDC）发挥的。还在兔主动脉平滑肌细胞（ASMC）培养物中研究了Atr对细胞增殖的作用。当培养基中存在Ca2+时，Atr抑制细胞生长。然而，当不存在Ca2+时，20.6 - 185.2μmol/L的Atr刺激细胞生长，但555.7 - 1666.7μmol/L的Atr抑制细胞生长，这表明Ca2+以某种方式参与了Atr对ASMC生长的作用。
