Veldhuis J D, Dufau M L
J Clin Invest. 1987 Sep;80(3):631-8. doi: 10.1172/JCI113115.
We investigated the effects of estradiol on bioactive luteinizing hormone (LH) release in normal men using two complementary strategies: (i) steady state intravenous infusions of estradiol at its endogenous production rate, and (ii) oral administration of the antiestrogen, tamoxifen HCl. Immunoreactive and biologically active LH were monitored by radioimmunoassay and the rat interstitial cell testosterone bioassay, respectively. Estradiol infusions significantly suppressed mean plasma bioactive LH concentrations and decreased the bio/immuno LH ratio. Conversely, antiestrogen treatment enhanced spontaneous bioactive LH pulse frequency, increased bioactive LH pulse amplitude, and augmented plasma intrapulse and interpulse bio/immuno LH ratios. Low-dose pulsed injections of exogenous gonadotropin-releasing hormone (GnRH) also increased plasma bio/immuno LH ratios. However, tamoxifen attenuated the ability of exogenous GnRH to further enhance the bio/immuno LH ratio, which suggests that endogenous LH release was already maximally enriched in LH bioactivity during antiestrogen administration. We conclude that estradiol modulates the pulsatile secretion of LH molecules enriched in biological activity in man.
我们采用两种互补策略研究了雌二醇对正常男性生物活性促黄体生成素(LH)释放的影响:(i)以其内源生成速率静脉内稳态输注雌二醇,以及(ii)口服抗雌激素药物盐酸他莫昔芬。分别通过放射免疫测定法和大鼠间质细胞睾酮生物测定法监测免疫反应性LH和生物活性LH。输注雌二醇显著抑制了平均血浆生物活性LH浓度,并降低了生物活性LH与免疫反应性LH的比值。相反,抗雌激素治疗提高了自发性生物活性LH脉冲频率,增加了生物活性LH脉冲幅度,并提高了血浆脉冲内和脉冲间生物活性LH与免疫反应性LH的比值。低剂量脉冲注射外源性促性腺激素释放激素(GnRH)也提高了血浆生物活性LH与免疫反应性LH的比值。然而,他莫昔芬减弱了外源性GnRH进一步提高生物活性LH与免疫反应性LH比值的能力,这表明在抗雌激素给药期间,内源性LH释放中的LH生物活性已达到最大富集。我们得出结论,雌二醇调节男性体内富含生物活性的LH分子的脉冲式分泌。