血管钠肽降低低氧大鼠心脏内皮素-1水平

目的　观察低氧对大鼠心脏内皮素 1(ET 1)水平的调节作用 ,以及血管钠肽 (VNP)对这一过程的影响。方法　将大鼠随机分为 4组 :对照组、低氧组、VNP(75 μg·kg-1)组和低氧 +VNP(2 5～ 75 μg·kg-1)组 ,采用放射免疫的方法测定大鼠心脏cGMP和ET 1水平 ,并以原位杂交的方法分析ET 1的mRNA水平。结果　低氧使大鼠心脏ET 1及其mRNA的水平升高 (P <0 0 5 ,vs对照组 ) ;VNP(5 0、75 μg·kg-1)使低氧大鼠心脏ET 1及其mRNA的水平降低 (P <0 0 5 ,vs低氧组 )。对照组和低氧组的心脏cGMP水平没有差异 ,而VNP组和低氧 +VNP(5 0、75 μg·kg-1)组的心脏cGMP水平高于对照组和低氧组 (P <0 0 5 )。结论　低氧可以使大鼠心脏ET 1及其mRNA的水平增加 ,而VNP可以抑制这一过程

Effect of vasonatrin peptide on cardiac endothelin-1 level in hypoxic rats

AIM The purpose of this study was to investigate effects of vasonatrin peptide (VNP) on cardiac endothelin 1 (ET 1) level in hypoxic rats. METHODS Rats were divided randomly into four groups: control group ,hypoxia group,VNP(75 μg·kg -1 body weight)group and hypoxia+VNP(25～75 μg·kg -1 body weight) group. The level of cGMP and ET 1 in rat hearts was measured by the means of radioimmunoassay, and in situ hybridization was used to examine ET 1 mRNA level in rat hearts. RESULTS Hypoxia significantly raised the level of ET 1 and its mRNA in rats ( P<0 05,vs control group),while VNP(50,75 μg·kg -1 body weight) significantly attenuated both cardiac ET 1 gene expression and ET 1 level in hypoxic rats (P<0 05,vs hypoxia group).The cGMP level in rat hearts of VNP(75 μg·kg -1 body weight) and hypoxia+VNP(50?75 μg·kg -1 body weight) groups was significantly higher than that of control and hypoxia groups( P< 0 05). CONCLUSION Hypoxia can significantly increase the expression of cardiac ET 1 gene in rats, which can be inhibited by VNP associated with cGMP.