微波辐射对大鼠睾丸StAR、P450scc基因表达影响

Effect of microwave irradiation on StAR and P450scc mRNA in testicle of rats

目的 研究微波暴露后大鼠睾丸组织类固醇合成急性调节蛋白(steroidogenicacuteregulatoryprotein ,StAR) ,细胞色素P4 5 0胆固醇侧链裂解酶(cytochromeP4 5 0Cholesterosidechainlyase ,P4 5 0scc)mRNA表达的变化和对睾酮分泌的影响,探讨微波暴露对成年雄性大鼠性功能影响的机制。方法 观测微波暴露后大鼠性功能,以扑捉潜伏期(capturelatentperiod ,CLP)和扑捉次数(capturetimes,CT)作为判别指标;采用RT PCR方法和放射免疫方法分别测定微波暴露后3,6 ,2 4 ,72h睾丸组织中StAR、P4 5 0sccmRNA水平及血清睾酮含量。结果 微波暴露后3h ,观测到雄性大鼠CLP明显延长(P <0 . 0 1) ,CP明显减少(P <0 .0 1) ,在观测的72h内,大鼠的性行为都较对照组明显下降。血清睾酮含量和睾丸组织StRA、P4 5 0sccmRNA变化有一致性,即在微波暴露后3h ,分别较对照降低83 .1% ,5 7. 3% ,5 3. 6 % (P <0. 0 1) ,6h略有回升,但仍明显低于对照组,2 4h恢复到正常水平,72h再次出现明显降低,分别较对照组降低5 7 .6 % ,39. 5 % ,5 3 .5 % (P <0 . 0 1)。结论 微波暴露可影响睾丸间质细胞StAR、P4 5 0sccmRNA表达而降低睾酮的合成,进而对雄性大鼠性行为造成影响。

Objective To study mRNA expression of steroidogenic acute regulatory protein(StAR) and cytochrme P450 cholestero side chain lyase(P450scc ) in testicle and excretion of testrone in blood of rats post microwave exposure ,and to interpret the molecular mechanism of microwave exposure on the sexual fu nction in adult rats.Methods Capture latent period(CLP)and capture times(CT) w ere used to estimate sexual function of exposed rats.Peverse transcription-poly merase chain(PCR)reaction method was used to determine the expression of StAR,P 450scc mRNA in testicle of rats 3,6,24,72h post microwave exposure and meanwhile testrone lever in blood serum was measured by radioimmunoassay.Results Prolonged CLP and decreased DT were found after 3 -hour exposure(P<0.01 respectively) and sexual behavior came down signific antly.Testrone and StAR,P450scc mRNA changed in the same situation,compaed with control and dareased 83.1%,57.3%,53.6% respectively(P<0.01) after 3-h our exposure and recovered to normal in 24h but reduced once again after 72h and were decreased 57.6%,39.5%,53.5% respectively(P<0.01).Conclusion Leydig cells can affect and decrease the ex pression of StAR,P450scc mRNA and testosterone synthesis,and further to influenc e the sexual function of male rats exposed to microwave.