C-型利钠利尿多肽对平滑肌细胞钙化的影响

目的 :在大鼠血管平滑肌细胞上观察C -型利钠利尿多肽 (C -typenatriureticpeptide ,CNP)对钙化的影响 ,探讨CNP对血管钙化的作用机制。方法 :β -磷酸甘油诱导培养的大鼠VSMCs钙化 ;通过VonKossa染色 ,细胞钙含量 ,45 Ca2 + 聚集 ,碱性磷酸酶活性测定 ,判断钙化程度 ,放射免疫分析方法测定VSMCs培养液中cAMP和cGMP含量。结果 :①β -磷酸甘油刺激平滑肌细胞生长、增殖和钙化 (P <0 .0 1) ;②CNP可降低钙化的VSMC的钙含量、4 5 Ca2 + 聚集、碱性磷酸酶活性 (P <0 .0 1) ;③CNP可以上调培养液中cGMP含量 ;④PKG抑制剂 -H8明显抑制CNP的效应。结论 :CNP主要是通过cGMP/PKG途径减轻 β -磷酸甘油诱导的VSMC钙化

Effects of C-type natriuretic peptide on VSMCs calcification

Objective In order to clarify the r eg ulating mechanism of vascular calcification, the investigators observed the effe cts of C-type natriuretic peptide (CNP) on the calcification in rat vascular smo oth muscle cells (VSMCs). Methods Calcification of culture d rat VSMCs was prepared by incubation with β-glycerophosphate. Calcification w as confirmed by Von Kossa staining, measurerment of calcium content, 45 Ca 2+ accumulation and alkaline phosphatases(ALP) activity of VSMCs. cGMP and cAMP levels in medium were measured using radioimmunoassary. Result ①beta-glycerophosphate stimulated growth?proliferation and calcifi cation in VSMCs(P<0.01). ② CNP attenuated the increases of 45 Ca 2+ accumulation, calcium content and ALP activity in calcified VSMCs(P<0. 01). ③CNP up-regulated cGMP content. ④ PKG inhibitor,H8, however, strongly a ntagonized all the inhibitory effects of CNP on calcification. Concl usions These data suggested that beta-glycerophosphate induced calcif ication in VSMCs was inhibited by CNP. CNP inhibited VSMCs' calcification partia lly through through cGMP/PKG pathway. This study could be of help in understandi ng the pathogenesis of vascular calcification, and providing new target for clin ical treatment of cardiovascular diseases associated with vascular calcification .