Physiological role of oxytocin on androgen production in the testis.

(1)雄激素(A)、催产素(OT)和前列腺素F_(2α)(PGF_(2α))之间的关系尚不清楚，它们都是由间质细胞产生的。本研究观察了催产素(OT)对成年雄性大鼠脑内A和PGF2α产生的影响，以及PGF2α对A和OT产生的影响。首先，将100 ng的OT或50*g的PGF2α注射到睾丸内，每天两次，连续4天。部分大鼠在处死前1.5小时经颈外静脉注射10IU人绒毛膜促性腺激素(HCG)。用人绒毛膜促性腺激素(HCG)刺激A产生，处死大鼠，测定睾丸激素浓度。OT降低T浓度，升高5α-双氢睾酮(DHT)和PGF2α浓度。注射人绒毛膜促性腺激素使T和DHT浓度升高，但OT或PGF2α对A产生…的影响不明显无论是否注射hCG，更多的是相似的。这些结果表明，在成年大鼠睾丸中，OT和PGF2α促进T的代谢，提示OT的作用是通过PGF2α介导的。(2)研究了成年山羊睾丸的基因表达、免疫组织化学定位、结合及OT对A产生的影响。通过聚合酶链式反应(P-CR)分析，我们已经能够在山羊睾丸中检测到OT基因的转录本。免疫组织化学显示，在肾小管内，尤其是支持细胞中，OT和神经生理蛋白表位共同表达，提示在这些细胞中产生了OT。然而，酶免疫分析发现，睾丸动脉和静脉血浆中的OT浓度没有差异。山羊睾丸膜部分有可饱和的、特异的[~3H]-OT结合部位。Scatchard分析表明其表观亲和力为42×7 L/nmol，结合容量为24×4 fmoL OT结合量/mg DNA。在体外，100 nM OT处理山羊睾丸6 h，DHT产量增加3.5倍(P&lt；0.00l)，这表明OT不仅影响睾酮的产生，还调节其向DHT的转化。这些结果表明，山羊睾丸产生OT，这可能参与A生物合成的局部调控。(热原学：提交)少

(1) The relationships among androgens (A), oxytocin (OT), and prostaglandin F2alpha(PGF2alpha), all of which are produced in Leydig cells, are not known. In this study, the effects of administration of OT on the production of A and PGF2alpha, or of PGF2alpha on the production of A and OT, in adult male rats were investigated. First, 100 ng of OT or 50*g of PGF2alpha was injected into a testis twice daily for 4 days. Some rats were injected with 10 IU of human chorionic gonadotropin (hCG) through the external jugular vein 1.5h before being sacrificed. hCG was given to stimulate the production of A.Rats were sacrificed and testicular hormone concentrations were measured. OT decreased T concentration and increased concentrations of 5alpha-dihydrotestosterone (DHT) and PGF2alpha. PGF2alpha decreased T concentration and tended to increase DHT concentration, but had no effect on OT.The injection of hCG increased the concentration of T and DHT, but the effects of OT or PGF2alpha on A producti … More on were similar whether hCG was injected or not. These results indicate that in adult rat testis, OT and PGF2alpha promote the metabolism of T, and suggest that the action of OT is mediated through PGF2alpha. (Prostaglandins & other Mediators 55 : 121-126, 1998)(2) Gene expression, immunohistochemical localization, binding, and effects of OT on A production in the testis of adult goats were studied. Using polymerase chain reaction (P CR) analysis we had been able to detect OT gene hanscripts in the goat testis. Immuno- histochemistry revealed that both OT and neurophysin epitopes were expressed together in the intratubular regions, especially in the Sertoli cells, suggesting the production of OT in these cells. However, enzyme immunoassay found no difference in OT concentration between testicular arterial plasma and venous plasma. Saturable, specific [3H]-OT binding sites were present in membrane fraction of the goat testis. Scatchard analysis indicated an apparent affinity of 42*7 L/nmol and binding capacity of 24*4 fmol OT bound/mg DNA.In vitro treatment of goat testes for 6 h with 100 nM OT led to a 3.5-fold increase (P<0.00l) in DHT production in spite of the induced decrease in testosterone, suggesting that OT not only affects testosterone production but also modulates its conversion to DHT.These results indicate that the goat testis produces OT, which may be involved in the local control of A biosynthesis. (Theriogenology : submitting) Less