妊娠期小鼠下丘脑-垂体-卵巢轴中PrRP和PrRP-R mRNA表达规律的研究

Expression of mRNA for PrRP and PrRP-R in Hypothalamus-pituitary-ovary Axis of Pregnant Mice

为探讨妊娠期小鼠下丘脑-垂体-卵巢轴中催乳素释放肽(PrRP)及其受体(PrRP-R)mRNA的表达规律,选用妊娠6、12、18 d小鼠(n=6),取下丘脑、垂体、卵巢组织,利用半定量PCR方法测定下丘脑-垂体-卵巢轴中PrRP和PrRP-R mRNA表达水平,另外利用放射免疫法(RIA)测定血浆孕酮(P)、雌二醇(E2)和催乳素(PRL)水平,探究下丘脑-垂体-卵巢轴PrRP和PrRP-R mRNA与血浆P、E2、PRL的相关关系。结果表明:妊娠期小鼠下丘脑、垂体、卵巢中都有PrRP、PrRP-R mRNA的表达,其中卵巢PrRP mRNA表达量较高,而下丘脑PrRP-R mRMA的表达量较高。妊娠期小鼠血浆P水平与垂体PrRP mRNA表达量呈显著负相关,而垂体PrRP mRNA与下丘脑PrRP-R mRNA表达量呈显著正相关,结果提示妊娠期血浆高水平的P可能通过抑制垂体PrRP mRNA的表达,进而作用于下丘脑参与妊娠相关调控。妊娠期小鼠血浆PRL水平与下丘脑、垂体、卵巢PrRP和PrRP-R mRNA的表达量均无显著相关关系,提示血浆PRL水平可能不受上述组织PrRP的影响。

To investigate PrRP and PrRP-R mRNA expression in hypothalamus-pituitary-ovary axis during pregnancy,hypothalamus, pituitary and ovary were sampled on 6, 12 and 18 days of pregnancy respectively for determination of PrRP and PrRP-R mRNA expression levels using semi-RT-PCR method. The concentration of plasma progesterone（P）, estrodiol（E2） and prolac- tin（PRL） were measured by RIA to probe their correlations with PrRP and PrRP-R mRNA. Re- sults indicated that both PrRP and PrRP-R mRNA were expressed in hypothalamus, pituitary and ovary during pregnancy. Ovary had highest PrRP mRNA level and hypothalamus had highest PrRP-R mRNA level. Correlation analysis results showed that plasma P had significant negative correlation with PrRP mRNA in pituitary, and PrRP mRNA in pituitary had significant positive correlation with PrRP-R mRNA in hypothalamus, which suggested that higher plasma P level during pregnancy might inhibit pituitary PrRP mRNA expression, then worked on hypothalamus to participate in pregnant regulation. The results showed that plasma PRL level had no signifant correlation with PrRP in pothalamus, pituitary and ovary, which further proved that plasma PRL level might not be regulated by tissue PrRP.