Bassett S G, Little-Ihrig L L, Mason J I, Zeleznik A J
Department of Physiology, University of Pittsburgh School of Medicine, Pennsylvania 15261.
J Clin Endocrinol Metab. 1991 Feb;72(2):362-6. doi: 10.1210/jcem-72-2-362.
To study further the control of the primate corpus luteum, we obtained corpora lutea from cynomolgus macaques at defined stages of the luteal phase and examined steady state mRNA levels in these corpora lutea by Northern analysis for the two major enzymes involved in progesterone biosynthesis, cytochrome P450 cholesterol side-chain cleavage (P450SCC) and 3 beta-hydroxysteroid dehydrogenase (3 beta HSD). mRNAs for both P450SCC and 3 beta HSD were maximal or near maximal shortly after ovulation and luteinization (days 3-5 of the luteal phase). mRNA for P450SCC exhibited a slight, but nonsignificant (P greater than 0.05) decline throughout the remainder of the luteal phase and was undetectable upon luteal regression. Steady state levels of 3 beta HSD mRNA were significantly lower (P less than 0.05) from corpora lutea removed during the midluteal phase (days 7-8 of the luteal phase) than those in newly formed corpora lutea and declined to 10% of early luteal phase values by days 13-15 of the luteal phase. 3 beta HSD mRNA levels fell to nondetectable values upon luteal regression. These results reveal a paradoxical relationship between the steroidogenic activity of the primate corpus luteum in vivo and the steady state levels of the mRNAs that encode for the major enzymes involved in progesterone biosynthesis. Unlike serum progesterone concentrations, which are very low immediately after ovulation and then rise during the midluteal phase, the steady stale levels of P450SCC mRNA and 3 beta HSD appeared to be maximal or near maximal shortly after ovulation and declined throughout the remainder of the luteal phase. These findings are consistent with the notion that luteal lifespan is set at the time of ovulation and luteinization, and the decline in luteal function may be due in part to decay of specialized luteal cell mRNAs with finite half-lives.
为了进一步研究灵长类动物黄体的调控机制，我们在黄体期的特定阶段从食蟹猴获取黄体，并通过Northern分析检测这些黄体中参与孕酮生物合成的两种主要酶，即细胞色素P450胆固醇侧链裂解酶（P450SCC）和3β-羟基类固醇脱氢酶（3βHSD）的稳态mRNA水平。P450SCC和3βHSD的mRNA在排卵和黄体化后不久（黄体期第3 - 5天）达到最大值或接近最大值。P450SCC的mRNA在黄体期的其余时间呈现轻微但无统计学意义（P大于0.05）的下降，在黄体退化时无法检测到。黄体中期（黄体期第7 - 8天）取出的黄体中3βHSD mRNA的稳态水平显著低于新形成的黄体，到黄体期第13 - 15天降至黄体早期水平的10%。3βHSD mRNA水平在黄体退化时降至无法检测的值。这些结果揭示了灵长类动物黄体在体内的类固醇生成活性与编码参与孕酮生物合成的主要酶的mRNA稳态水平之间的矛盾关系。与排卵后立即非常低然后在黄体中期升高的血清孕酮浓度不同，P450SCC mRNA和3βHSD的稳态水平在排卵后不久似乎达到最大值或接近最大值，并在黄体期的其余时间下降。这些发现与黄体寿命在排卵和黄体化时设定的观点一致，黄体功能的下降可能部分归因于具有有限半衰期的特殊黄体细胞mRNA的降解。
