Köppel H, Holzmann S, Klein W, Horn E, Horn S, Gasser R
Department of Internal Medicine, University of Graz, Austria.
Heart Vessels. 1996;11(4):192-6. doi: 10.1007/BF02559991.
Angiotensin-converting enzyme (ACE) inhibitors are widely used in the management of hypertension, heart failure, and nephropathy. It has been suggested that ACE inhibitors containing the sulfhydryl group (SH) have an additional effect on KATP channels. To prove this hypothesis, we studied the effects of the SH-containing ACE inhibitors, captopril and zofenopril, on KATP channel opening of bovine coronary arteries and guinea pig thoracic aortas. Bovine coronary arteries were precontracted with the thromboxane A2 analogue, U46619, and guinea pig thoracic aortas were precontracted with phenylephrine and then relaxed with either captopril or zofenopril (n = 8). Inhibition of KATP channel opening with glibenclamide moderately attenuated the zofenopril-induced relaxation of guinea pig thoracic aorta. However, in the bovine coronary arteries, the relaxing effect of both captopril and zofenopril remained uneffected by glibenclamide. In experiments with enalapril (a non SH-containing ACE inhibitor; n = 6) on guinea pig thoracic aortas, no effect on KATP channels could be seen. From our experiments, we conclude that the postulated opening of KATP channels by SH-group-containing ACE inhibitors contributes little to the vasodilation of guinea pig thoracic aortas caused by ACE inhibitors, and that SH groups have no influence upon KATP channels of bovine coronary arteries.
血管紧张素转换酶（ACE）抑制剂广泛应用于高血压、心力衰竭和肾病的治疗。有研究表明，含巯基（SH）的ACE抑制剂对ATP敏感性钾通道（KATP通道）具有额外作用。为证实这一假设，我们研究了含SH的ACE抑制剂卡托普利和佐芬普利对牛冠状动脉和豚鼠胸主动脉KATP通道开放的影响。牛冠状动脉用血栓素A2类似物U46619预收缩，豚鼠胸主动脉用去氧肾上腺素预收缩，然后分别用卡托普利或佐芬普利使血管舒张（n = 8）。用格列本脲抑制KATP通道开放可适度减弱佐芬普利诱导的豚鼠胸主动脉舒张。然而，在牛冠状动脉中，卡托普利和佐芬普利的舒张作用均不受格列本脲影响。在用依那普利（一种不含SH的ACE抑制剂；n = 6）对豚鼠胸主动脉进行的实验中，未观察到对KATP通道有影响。从我们的实验中，我们得出结论，含SH基团的ACE抑制剂假定的KATP通道开放对ACE抑制剂引起的豚鼠胸主动脉血管舒张作用不大，且SH基团对牛冠状动脉的KATP通道没有影响。
