C-型利钠利尿肽在球囊血管损伤中的作用

The role of C type natriuretic peptide in balloon injury of rat aorta

目的：在大鼠主动脉球囊剥脱模型上观察血浆和主动脉组织Ｃ型利钠利尿肽（Ｃｔｙｐｅ ｎａｔｒｉｕｒｅｔｉｃ ｐｅｐｔｉｄｅ，ＣＮＰ）的质量浓度和ｍＲＮＡ 表达的动态变化及外源性ＣＮＰ对大鼠球囊损伤后内膜生成的影响，以探讨ＣＮＰ在再狭窄中的作用。方法：放射免疫法测定ＣＮＰ质量浓度，ＲＴＰＣＲ 测定ＣＮＰｍＲＮＡ 的表达。结果：发现大鼠球囊损伤后血浆ＣＮＰ的质量浓度升高， 内膜剥脱后第３ 天、１０ 天、２１ 天，血浆ＣＮＰ 水平分别增高８０ ．７％ （ Ｐ＜ ０．０１） ，４３．５ ％ （Ｐ＜ ０．０５） 和２７ ．５％ （Ｐ＜ ０．０５），而主动脉组织ＣＮＰ含量在损伤后第３ 天下降４６ ．６％ （Ｐ＜ ０．０５） ，第１０ 天，２１ 天和２８ 天ＣＮＰ含量分别增加２ ．８ 倍（ Ｐ＜ ０ ．０１） 、１．６ 倍（ Ｐ＜ ０ ．０５） 和０ ．８２ 倍（Ｐ＜ ０．０５）。在血管损伤３ 天时ＣＮＰｍＲＮＡ 的表达减弱，而第１０ 天和第２１ 天ＣＮＰｍＲＮＡ 的表达明显增强。外源性ＣＮＰ显著抑制球囊损伤后第７ 天和２１ 天新生内膜的形成，内膜／中膜比值分别降低２３％ （Ｐ＜ ０．０５）和２０ ％ （Ｐ＜０ ．０５）。结论：ＣＮＰ参与血管球囊损伤后的修复过程，可能是机体?

Objective: To study the dynamic changes of C type natriuretic peptide(CNP) in plasma and aortic tissues and the effect of exogenous CNP on intima/media (I/M) ratios in a model of balloon injury of rat aorta Methods:CNP levels in plasma and aorta were determined by radioimmunoassay. CNP mRNA expression was measured by RT PCR technique. Results: CNP levels in plasma were significantly increased by 80.7% ( P <0.01), 43.5% ( P <0.05) and 27.5% ( P <0.05) 3 days, 10 days and 21 days after balloon injury, but its levels in aortic tissues were decreased by 46.6% ( P < 0.05 ) on day 3 and increased by 2.8 ( P <0.01), 1.6 ( P <0.05) and 0.82 fold ( P <0.05) on day 10, day 21 and day 28 after balloon injury of rat aorta. In the meanwhile, CNP mRNA expression was also increased on day 10, day 21. Results also showed that the administration of CNP i.p. inhibited neointima formation. I/M ratios were decreased by 23%( P <0.05) and 20%( P <0.05) 7 days, and 21 days after balloon injury of rat aorta. Conclusion: CNP might be involved in the process of recovery after vascular endothelium denudation and exogenous CNP suppressed the neointima formation.