Nishihara M, Winters C A, Buzko E, Waterman M R, Dufau M L
Section on Molecular Endocrinology, National Institute of Child Health and Human Development, Bethesda, Maryland 20892.
Biochem Biophys Res Commun. 1988 Jul 15;154(1):151-8. doi: 10.1016/0006-291x(88)90663-8.
We have isolated and characterized a P-45017 alpha cDNA fragment from a rat testis library. The partial length rat P-45017 alpha cDNA (1Kb) has high overall nucleotide and deduced amino acid similarity with human and bovine P-45017 alpha cDNA's and contains the conserved tridecapeptide and heme regions, the termination codon and polyadenylation site. Using this rat testis cDNA probe we measured P-45017 alpha mRNA levels of rat Leydig cells from animals treated with hCG. Temporal studies with a low hCG dose showed an early increase in mRNA levels returning to control values at later times, while a higher desensitizing dose caused a marked reduction in the mRNA (24 h) and a small recovery at 48 h. Fetal rat Leydig cells maintained in the presence of LH treated with estradiol showed a 70% decrease in P-45017 alpha mRNA levels and testosterone production followed closely the changes in P-45017 alpha mRNA. These studies suggest that gonadotropin stimulation and desensitization of P-45017 alpha dependent enzymes in the adult rat testis as well as estradiol induced desensitization in fetal Leydig cells are related to levels P-45017 alpha mRNA.
我们从大鼠睾丸文库中分离并鉴定了一个P - 45017α cDNA片段。大鼠P - 45017α cDNA的部分长度（1Kb）与人和牛的P - 45017α cDNA在总体核苷酸和推导的氨基酸序列上具有高度相似性，并且包含保守的十三肽和血红素区域、终止密码子和多聚腺苷酸化位点。使用该大鼠睾丸cDNA探针，我们检测了用hCG处理的动物的大鼠睾丸间质细胞中P - 45017α mRNA的水平。低剂量hCG的时间研究显示，mRNA水平早期升高，随后恢复到对照值，而较高的脱敏剂量导致mRNA显著降低（24小时），并在48小时时有小幅度恢复。在存在LH的情况下用雌二醇处理的胎鼠睾丸间质细胞显示，P - 45017α mRNA水平下降70%，睾酮生成与P - 45017α mRNA的变化密切相关。这些研究表明，成年大鼠睾丸中促性腺激素对P - 45017α依赖性酶的刺激和脱敏作用，以及雌二醇诱导的胎鼠睾丸间质细胞脱敏作用，均与P - 45017α mRNA水平有关。
