Welling A, Felbel J, Peper K, Hofmann F
II. Physiologisches Institut, Medizinische Fakultät, Universität des Saarlandes, Homburg/Saar, BRD.
Blood Vessels. 1991;28(1-3):154-8. doi: 10.1159/000158855.
The hormonal regulation of L-type calcium current was investigated in freshly isolated tracheal smooth muscle cells using the whole-cell configuration of the patch-clamp technique. Isoproterenol stimulated the L-type calcium current 2.6-fold through beta-adrenoceptors. Dialysis of these cells with cyclic AMP, cyclic AMP analogues or the catalytic subunit of cyclic AMP kinase had no effect on basal or isoproterenol-stimulated calcium current. The calcium current was stimulated and inhibited by dialysis of the cells with GTP gamma S and GDP beta S, respectively. Evidently, in some smooth muscle cells the beta-adrenoceptor couples directly to L-type calcium channels via a G protein.
利用膜片钳技术的全细胞模式，在新鲜分离的气管平滑肌细胞中研究了L型钙电流的激素调节。异丙肾上腺素通过β-肾上腺素能受体使L型钙电流增强2.6倍。用环磷酸腺苷、环磷酸腺苷类似物或环磷酸腺苷激酶的催化亚基对这些细胞进行透析，对基础钙电流或异丙肾上腺素刺激的钙电流均无影响。分别用GTPγS和GDPβS对细胞进行透析，可刺激和抑制钙电流。显然，在某些平滑肌细胞中，β-肾上腺素能受体通过G蛋白直接与L型钙通道偶联。
