Veldhuis J D, Dufau M L
Trans Assoc Am Physicians. 1986;99:236-44.
We evaluated the impact of estradiol on bioactive LH release in normal men by steady-state intravenous infusions of estradiol and oral administration of the antiestrogen tamoxifen HCl. The secretion of biologically active LH was monitored by the rat interstitial cell testosterone bioassay. Estradiol infusions decreased mean plasma bioactive LH concentrations and diminished the bio/immuno LH ratio. Conversely, the antiestrogen tamoxifen increased bioactive LH pulse frequency, bioactive LH pulse amplitude, and the plasma bio/immuno LH ratio. Exogenous injections of GnRH at 2-hr intervals also increased the bio/immuno LH ratio basally. However, tamoxifen attenuated the ability of exogenous GnRH to increase the bio/immuno LH ratio further, indicating attainment of maximal enrichment in LH bioactivity. These complementary observations on the impact of infused estradiol and exogenous antiestrogen indicate that estradiol modulates the pulsatile secretion of LH molecules enriched in biological activity in man.
我们通过静脉内稳态输注雌二醇以及口服抗雌激素药物盐酸他莫昔芬,评估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。采用大鼠间质细胞睾酮生物测定法监测生物活性LH的分泌。输注雌二醇降低了平均血浆生物活性LH浓度,并降低了生物活性LH与免疫活性LH的比值。相反,抗雌激素药物他莫昔芬增加了生物活性LH脉冲频率、生物活性LH脉冲幅度以及血浆生物活性LH与免疫活性LH的比值。每隔2小时进行一次外源性促性腺激素释放激素(GnRH)注射也会使基础生物活性LH与免疫活性LH的比值增加。然而,他莫昔芬减弱了外源性GnRH进一步增加生物活性LH与免疫活性LH比值的能力,这表明LH生物活性已达到最大富集程度。这些关于输注雌二醇和外源性抗雌激素影响的互补性观察结果表明,雌二醇可调节男性体内富含生物活性的LH分子的脉冲式分泌。