高温对大鼠血管活性物质含量及脂质过氧化的影响

目的　探讨高温对大鼠内皮素 (ET)、心钠素 (ANP)、内源性洋地黄物质 (EDLS)释放及脂质过氧化的影响。方法　将 4 8只Wistar大鼠随机分为对照组、热习服组、热应激组。用放射免疫法测定ET、ANP、EDLS及超氧化物歧化酶 (SOD)含量 ,分光光度法测定丙二醛 (MDA)含量。结果　 3组间ET含量差异无显著性 (P >0 0 5 ) ;热习服组和热应激组大鼠血浆ANP含量明显低于对照组 ,差异有显著性(P <0 0 5 ) ;热习服组与热应激组的EDLS含量明显高于对照组 ,差异有显著性 (P <0 0 1)。热习服组和热应激组大鼠血清SOD含量明显低于对照组 (P <0 0 1)。MDA含量比较 ,热应激组高于对照组 ,差异有显著性 (P <0 0 1) ,热习服组与对照组比较 ,差异无显著性 (P >0 0 5 )。结论　高温环境对大鼠ANP、EDLS水平有影响 ,热习服与热应激后导致ANP明显下降 ,而EDLS含量明显升高。大鼠质脂过氧化作用增强 ,抗氧化酶作用减弱。

Effect of Heat on Lipid Peroxidation and Release of Endothelin,ANP,and EDLS in Rats

Objective To explore the effects of heat on lipid oxidation and the release of endothelin(ET), arterial natriuretic peptide(ANP) and endogenous digitalis-like substance(EDLS) in rats.Methods 48 wistar rats were randomly divided into 3 groups:heat adaptation(HA) group,heat stress(HS) group and control group.The levels of ET,ANP,EDLS and superoxide dismutase(SOD)were determined by radioimmunoassay(RIA)and MDA by spectrophotometry.Results The results showed that no significant differences were found in the levels of plasma ET among three groups of rats(P>0.05). As compared with the control group,the levels of plasma ANP in HA and HS groups were obviously lower(P<0.05), while the levels of EDLS were markedly higher( P<0.01 ).The differences were statistically significant.As the levels of MDA and HS were statistically higher than the control(P<0.01), however,the difference between HA group and control was not significant.Conclusions Heat may influence the levels of ANP and EDLS.Heat stress and heat adaptation may induce decrease in ANP,weaken the activities of antioxidant enzymes,increase in EDLS and enhance the lipid peroxidation in rats.