Hall A K, Aten R, Behrman H R
Department of Surgery, University of Medicine and Dentistry, New Jersey Medical School, Newark 07103-2757.
Endocrinology. 1991 Feb;128(2):951-7. doi: 10.1210/endo-128-2-951.
We have investigated thymosin beta 10 mRNA levels in the PMSG/hCG-treated immature rat ovary. Thymosin beta 10 mRNA was constitutively expressed as a single (greater than 600-nucleotide) abundant transcript in the immature rat ovary. Administration of a single dose (50 IU/rat) of PMSG to immature rats resulted in a gradual increase in steady state ovarian thymosin beta 10 mRNA content detectable as early as 12 h and maximal (2-to 3-fold stimulation above preinjection levels) 48 h after PMSG treatment. Ovarian thymosin beta 10 mRNA levels declined thereafter. In separate experiments treatment of PMSG (50 IU)-primed rats with hCG (25 IU) precipitated a dramatic (80%) inhibition of ambient ovarian thymosin beta 10 protein and thymosin beta 10 mRNA; both parameters remained suppressed for the duration of the hormone-induced pseudopregnancy (15 days). HPLC analysis also indicated the presence in the ovary of thymosin beta 4, a variant member of the same protein family; in general, ovarian thymosin beta 4 levels fluctuated in a manner reciprocal to that exhibited by thymosin beta 10. A luteolytic dose of prostaglandin F2 alpha (500 micrograms/rat) had little impact on ovarian thymosin beta 10 gene expression. These findings show that 1) PMSG stimulation of ovarian thymosin beta 10 biosynthesis involves increased expression of the thymosin beta 10 gene; 2) decreased expression of thymosin beta 10 is associated with luteinization, while increased thymosin beta 4 levels characterize this process; and that 3) thymosin beta 4 and beta 10 are coexpressed in this tissue and may play a significant but, as of yet, undefined role(s) in the ovary.
我们研究了孕马血清促性腺激素（PMSG）/人绒毛膜促性腺激素（hCG）处理的未成熟大鼠卵巢中胸腺素β10 mRNA的水平。胸腺素β10 mRNA在未成熟大鼠卵巢中以单一（大于600个核苷酸）丰富转录本的形式组成性表达。给未成熟大鼠单次注射（50 IU/只）PMSG后，稳态卵巢胸腺素β10 mRNA含量逐渐增加，早在12小时即可检测到，在PMSG处理后48小时达到最大值（比注射前水平增加2至3倍）。此后卵巢胸腺素β10 mRNA水平下降。在单独的实验中，用hCG（25 IU）处理经PMSG（50 IU）预处理的大鼠，导致卵巢中胸腺素β10蛋白和胸腺素β10 mRNA显著（80%）抑制；在激素诱导的假孕（15天）期间，这两个参数一直受到抑制。高效液相色谱分析还表明卵巢中存在胸腺素β4，它是同一蛋白家族的变体成员；一般来说，卵巢胸腺素β4水平的波动方式与胸腺素β10相反。黄体溶解剂量的前列腺素F2α（500微克/只）对卵巢胸腺素β10基因表达影响不大。这些发现表明：1）PMSG刺激卵巢胸腺素β10生物合成涉及胸腺素β10基因表达增加；2）胸腺素β10表达降低与黄体化有关，而胸腺素β4水平升高是该过程特征；3）胸腺素β4和β10在该组织中共表达，可能在卵巢中发挥重要但尚未明确界定的作用。
