Lee K, Groh W J, Blair T A, Maylie J G, Adelman J P
Vollum Institute for Advanced Biomedical Research, Oregon Health Sciences University, Portland 97201, USA.
Eur J Pharmacol. 1995 Oct 24;285(3):309-12. doi: 10.1016/0014-2999(95)00525-p.
Phentolamine and related imidazolines inhibit KATP channel activity in the pancreatic beta cell. In the present study, the effects of several imidazoline-based compounds were examined upon KATP channel activity in guinea pig ventricular myocytes. Phentolamine produced a potent inhibition of KATP channel activity when examined in either excised inside-out patches or in the whole-cell configuration. This effect was unrelated to phentolamine's ability to antagonise alpha-adrenoceptors since the nonselective alpha-adrenoceptor antagonists, benextramine and phenoxybenzamine, failed to affect channel activity. Furthermore, the alpha-adrenoceptor agonist clonidine together with several related imidazolines inhibited channel activity. This suggests that imidazoline compounds modulate KATP channel activity in guinea pig ventricular myocytes and this may have clinical implications for the use of such agents as hypoglycemic drugs.
酚妥拉明及相关咪唑啉类化合物可抑制胰腺β细胞中的ATP敏感性钾通道（KATP通道）活性。在本研究中，检测了几种基于咪唑啉的化合物对豚鼠心室肌细胞KATP通道活性的影响。在膜片钳实验中，无论是采用内面向外式膜片还是全细胞模式进行检测，酚妥拉明均能显著抑制KATP通道活性。这种效应与酚妥拉明拮抗α-肾上腺素能受体的能力无关，因为非选择性α-肾上腺素能受体拮抗剂苯苄胺和酚苄明未能影响通道活性。此外，α-肾上腺素能受体激动剂可乐定以及几种相关咪唑啉类化合物也能抑制通道活性。这表明咪唑啉类化合物可调节豚鼠心室肌细胞中的KATP通道活性，这可能对这类药物作为降血糖药物的应用具有临床意义。
