慢性缺氧对大鼠血浆内皮素及心肌ETRa、CaM和CaMKII的影响

Impact of chronic hypoxia on plasma endothelin and ETRa,CaM,CaMKII in cardiac cells

目的:研究慢性缺氧对大鼠血浆内皮素和心肌酶的影响。方法:以常压缺氧方式建立缺氧动物模型,SD幼鼠被随机分为3组:正常组、缺氧1周组和缺氧3周组,通过酶联免疫吸附试验检测不同组动物血浆内皮素变化,通过RT-PCR方法检测心肌组织中ETRa、CaM、CaMK II的mRNA表达。结果:血浆内皮素水平随缺氧时间延长而升高,正常组、缺氧1周组和缺氧3周组比较均有差异(P<0.05)。同时,心肌细胞ETRa、CaM、CaMK II mRNA的转录水平也随缺氧时间延长而增加,缺氧1周组和正常组比较有差异(P<0.05);但缺氧3周组和缺氧1周组比较有所不同,CaM和CaMK IIδ转录水平表现有差异(P<0.05),而ETRa和CaMK IIγ转录水平无差异(P>0.05)。结论:慢性缺氧使动物血浆中内皮素水平升高,心肌细胞ETRa、CaM和CaMK II mRNA转录增加,可能会对心脏功能产生影响。

AIM：To investigate the impact of chronic hypoxia on the changes of plasma endothelin concentration and myocardial enzymes in rats. METHODS：A hypoxia model was established on SD rats under normal air pressure with FiO2： 10%. The rats were randomly divided into three groups： the normal group, the group with 1 week, and the group with 3 week hypoxia. The levels of plasma endothelin were measured using ELISA method and the transcription of mRNA of ETRa, CaM and CaMKII were tested by RT-PCR. RESULTS ： Hypoxia elevated the levels of plasma endothelin in a time-dependent manner with significant differences among three groups （P 〈 0.05）. The transcriptions of mRNA of ETRa, CaM, and CaMKII were also significantly upregulated in 1 week group （ P 〈 0.05 ） and 3 week group. Between the two groups ; the transcription of mRNA of CaM and CaMKⅡδ were significant different （P 〈 0.05 ） , while ETRa and CaMKⅡγ were unchanged （P 〉 0.05 ）. CONCLUSION： The hypoxia induced elevation of plasma endothelin and upregulation of the transcription of mRNA of ETRa, CaM and CaMKII may exert some impacts on cardiac functions.