Srivastava C H, Breyer P R, Rothrock J K, Peredo M J, Pescovitz O H
Section of Endocrinology/Diabetology, Indiana University Medical Center, Indianapolis 46202.
Endocrinology. 1993 Sep;133(3):1478-81. doi: 10.1210/endo.133.3.7689961.
A GHRH-like mRNA and peptide (t-GHRH) have been detected in rat and human testis. In rat, t-GHRH mRNA is localized to developing spermatogenic cells. We predicted that the most likely target cell of t-GHRH action would be the Sertoli cell. To test this prediction, we evaluated GHRH action on Sertoli cell function. Rat GHRH at a concentration of 10 nM or 100 nM stimulated cAMP production 2-fold over control levels after a 30 min incubation. This stimulation was obliterated by preincubation with a 10-fold excess of the GHRH antagonist (N-Ac-Tyr1, D-Arg2)-GRF(1-29)-NH2. The effect of treatment with [His1,Nle27]GHRH(1-32)-NH2, a GHRH analog, on Sertoli cell mRNAs was also assessed. Treatment with the analog significantly increased levels of c-fos and steel factor (the product of the Steel gene, also termed SCF) mRNAs above controls, but had no effect on sulfated glycoprotein-2 mRNA. We conclude that GHRH acts via adenylate cyclase to modulate specific Sertoli cell products, possibly as part of a network of local interacting factors controlling Sertoli and germ cell function.
在大鼠和人类睾丸中已检测到一种类似生长激素释放激素（GHRH）的信使核糖核酸（mRNA）和肽（t-GHRH）。在大鼠中，t-GHRH mRNA定位于发育中的生精细胞。我们预测t-GHRH作用最可能的靶细胞是支持细胞。为验证这一预测，我们评估了GHRH对支持细胞功能的作用。在孵育30分钟后，浓度为10 nM或100 nM的大鼠GHRH刺激环磷酸腺苷（cAMP）生成，使其比对照水平增加了2倍。用过量10倍的GHRH拮抗剂（N-乙酰基-Tyr1，D-精氨酸2）-生长激素释放因子（GRF）（1-29）-NH2预孵育可消除这种刺激作用。还评估了用GHRH类似物[组氨酸1，Nle27]GHRH（1-32）-NH2处理对支持细胞mRNA的影响。用该类似物处理显著增加了c-fos和钢因子（Steel基因的产物，也称为干细胞因子，SCF）mRNA水平，使其高于对照，但对硫酸化糖蛋白-2 mRNA无影响。我们得出结论，GHRH通过腺苷酸环化酶起作用，调节支持细胞的特定产物，这可能是控制支持细胞和生殖细胞功能的局部相互作用因子网络的一部分。
