组胺对豚鼠心室肌细胞延迟外向钾电流的调制作用。

Modulation by histamine of the delayed outward potassium current in guinea-pig ventricular myocytes.

作者信息

Yazawa K, Abiko Y

机构信息

Department of Pharmacology, Asahikawa Medical College, Japan.

出版信息

Br J Pharmacol. 1993 May;109(1):142-7. doi: 10.1111/j.1476-5381.1993.tb13544.x.

DOI:10.1111/j.1476-5381.1993.tb13544.x

原文链接:https://pmc.ncbi.nlm.nih.gov/articles/PMC2175605/

Abstract

Histamine receptor-mediated modulation of the delayed outward potassium current (IK) was investigated in guinea-pig single ventricular cells by the whole-cell voltage clamp. 2. Histamine increased IK in a dose- dependent manner with a half-maximum dose of 3.8 x 10(-8) M. Histamine (10(-6) M) increased IK by a factor of 3.02 without a significant change in the current kinetics. The threshold dose of histamine for increasing IK was 10(-9) M and this value was similar to that for calcium current. 3. Cimetidine decreased IK in the presence of histamine, by shifting the dose-response curve to histamine to the right. The pA2 value of cimetidine against histamine was 6.38. 4. Forskolin did not increase IK after application of 10(-6) M histamine, and histamine scarcely increased IK in the presence of a heat-stable inhibitor of cyclic AMP-dependent protein kinase (PKI). 5. We conclude that stimulation by histamine of IK is mainly by way of the H2-receptor, and is mediated by cyclic AMP-dependent phosphorylation.

摘要

采用全细胞膜片钳技术研究了组胺受体介导的豚鼠单个心室细胞延迟外向钾电流（IK）的调节作用。2. 组胺以剂量依赖方式增加IK，半数最大效应剂量为3.8×10⁻⁸ M。组胺（10⁻⁶ M）使IK增加3.02倍，电流动力学无显著变化。组胺增加IK的阈剂量为10⁻⁹ M，该值与钙电流的阈剂量相似。3. 西咪替丁在有组胺存在时降低IK，使组胺的剂量-反应曲线右移。西咪替丁对组胺的pA2值为6.38。4. 应用10⁻⁶ M组胺后，福斯高林未增加IK，在存在环磷酸腺苷依赖性蛋白激酶的热稳定抑制剂（PKI）时，组胺也几乎不增加IK。5. 我们得出结论，组胺对IK的刺激主要通过H2受体，且由环磷酸腺苷依赖性磷酸化介导。