Effects of stimulant and relaxant drugs on tension and cyclic nucleotide levels in canine femoral artery.
Effects of stimulant and relaxant drugs on tension and cyclic nucleotide levels in canine femoral artery.
复制标题
兴奋剂和松弛剂药物对犬股动脉张力和环核苷酸水平的影响。
作者：
J. Diamond;K. Blisard
同时监测暴露于不同药物的犬股动脉离体条的环核苷酸水平和等长张力。苯肾上腺素(5µM)可引起血管条持续收缩，但对组织中鸟苷39，59-环一磷酸或腺苷39，59-环一磷酸的水平无明显影响。卡巴胆碱(100µM)对动脉的张力没有影响，但显著增加了组织中cGMP的水平，但对cAMP的水平没有影响。罂粟碱(100微米)和硝酸甘油(200微米)均持续松弛苯肾上腺素收缩的股动脉，并显著增加其环化GMP水平。在罂粟碱诱导的松弛过程中，循环GMP水平增加了73%，在硝酸甘油诱导的松弛过程中，循环GMP水平增加了154%。在这些条件下，两种药物对cAMP水平均无显著影响。这些结果与早期的观点不一致，即血管平滑肌的收缩和松弛分别是由组织中环GMP和环AMP水平的增加所介导的。
Cyclic nucleotide levels and isometric tension were monitored simultaneously in isolated strips of canine femoral arteries after exposure to various drugs. Phenylephrine (5 µM) produced sustained contractions of the vascular strips but had no significant effect on tissue levels of guanosine 39,59-cyclic monophosphate or adenosine 39,59-cyclic monophosphate. Carbachol (100 µM), which had no effect on the tension developed by the arteries, significantly increased tissue levels of cyclic GMP but not of cyclic AMP. Papaverine (100 µM) and nitroglycerin (200 µM) both consistently relaxed phenylephrine-contracted femoral arteries and significantly increased their cyclic GMP levels. Cyclic GMP levels were increased by as much as 73% during papaverine-induced relaxation, and by 1540% during nitroglycerin-induced relaxation. Neither drug had any significant effect on cyclic AMP levels under these conditions. These results are not consistent with the earlier suggestion that contraction and relaxation of vascular smooth muscle are mediated by increases in tissue levels of cyclic GMP and cyclic AMP, respectively.