[Effect of vasonatrin peptide on the Ca2+ activated K+ channels of vascular smooth muscle cells isolated from rat mesentery arteries].

Aim: To investigate effect and mechanism of vasonatrin peptide (VNP) on Ca2+ activated K+ channels (K(Ca)) of vascular smooth muscle cells (VSMCs) isolated from rat mesentery arteries.

Methods: Changes of K(Ca) 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: K(Ca) 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 x 10(-5) mol/L).

Conclusion: VNP increases K(Ca) of VSMCs isolated from rat mesenteric arteries, by binding with natriuretic peptide guanylate cyclase-coupled receptors and increasing the intracellular level of cGMP in VSMCs.