【摘要】 本文旨在研究雌激素对动脉平滑肌细胞大电导钙激活钾通道(large-conductance Ca2+-activated potassium channels,BKCa)的作用。取绝经后女性患者手术切除物中的肠系膜动脉,应用急性酶分离法分离出肠系膜动脉平滑肌细胞,按动脉平滑肌细胞的来源分为非高血压(non-hypertension,NH)组及原发性高血压病(essential hypertension,EH)组,采用单通道膜片钳技术研究β-雌二醇(β-estradiol,β-E2)及其受体(ER)抑制剂ICI182780对BKCa的作用。结果显示,肠系膜动脉平滑肌细胞BKCa通道的开放具有电压依赖性和钙依赖性,可被IbTX所阻断。100μmol/Lβ-E2能够显著增加NH和EH组BKCa的通道开放概率(open probability,Po),且β-E2处理后NH组BKCa的通道Po显著大于EH组。ICI182780可显著抑制β-E2对BKCa通道的增强作用。以上结果提示,β-E2能够通过激活ER显著增强绝经后妇女肠系膜动脉平滑肌细胞的BKCa功能,而高血压可以削弱β-E2对动脉平滑肌细胞BKCa功能的增强作用。更多还原

【Abstract】 The aim of the present study was to study the effect of β-estradiol (β-E2) on the large-conductance Ca2+-activated potassium (BKCa) channel in mesenteric artery smooth muscle cells (SMCs).The mesenteric arteries were obtained from post-menopause female patients with abdominal surgery,and the SMCs were isolated from the arteries using an enzymatic disassociation.According to the sources,the SMCs were divided into non-hypertension (NH) and essential hypertension (EH) groups.Single channel patch clamp technique was used to investigate the effect of β-E2 and ICI 182780 (a specific blocker of estrogen receptor) on BKCa in the SMCs.The results showed the opening of BKCa in the SMCs was voltage and calcium dependent,and could be blocked by IbTX.β-E2 (100 μmol/L) significantly increased open probability (Po) of BKCa in both NH and EH groups.After β-E2 treatment,NH group showed higher Po of BKCa compared with EH group.ICI 182780 could inhibit the activating effect of β-E2 on BKCa in no matter NH or EH groups.These results suggest β-E2 activates BKCa in mesenteric artery SMCs from post-menopause women via estrogen receptor,but hypertension may decline the activating effect of β-E2 on BKCa.更多还原