中文摘要：

目的：研究血管钠肽（VNP）对大鼠肠系膜动脉血管平滑肌细胞（VSMCs）Ca^2＋激活K^＋通道（KCa）的作用及其机制。方法：采用全细胞膜片钳技术观察VNP对K已的影响，以及HS-142-1、8-Br-cGMP和美蓝（MB）在这一过程中的作用。结果：OVNP（10^-6mol／L）显著增强KCa（P〈0．05，n=5）。②8-Br-CGMP（10^-3mol／L）模拟VNP增强Kca的作用（P〈0．05，n=6）。QHS-142-1（2×10^-5mol／L）MB（10^-5mol／L）完全阻断VNP增加K已电流密度的作用。结论：VNP通过作用于VSMCs的钠尿肽GC耦联受体，升高细胞内的cGMP水平，激活KCa。

英文摘要：

Aim： To investigate effect and mechanism of vasonatrin peptide（VNP） on Ca^2＋ activated K^＋ channels（KCa） of vascular smooth muscle cells（VSMCs） isolated from rat mesentery arteries. Methods： Changes of Kc, induced by VNP were measured by the means of whole cell recording mode of patch clamp, furthermore effects of HS-142-1 （0.3 g/L）, 8-Br-cGMP and methylene blue（MB） were observed. Results： KCa was significantly enhanced by VNP（ 10^-6 mol/L）, which was mimicked by 8-Br-cGMP（ 10^-3 mol/L） and blocked completely by HS-142-1 or MB（2 ×10^-5 mol/L）. Conclusion： VNP increases KCa of VSMCs isolated from rat mesenteric arteries, by binding with natriuretic peptide guanylate cyclase-coupled receptors and increasing the intracellular level of cGMP in VSM- Cs.