Reame N E, Kelche R P, Beitins I Z, Yu M Y, Zawacki C M, Padmanabhan V
School of Nursing, University of Michigan Medical Center, Ann Arbor, 48109, USA.
J Clin Endocrinol Metab. 1996 Apr;81(4):1512-8. doi: 10.1210/jcem.81.4.8636360.
To characterize the differential aging response in gonadotropin secretion that occurs before menopause, we assessed pulsatile LH and serial FSH, estradiol (E2), and progesterone (P) concentrations in aging women across the menstrual cycle. We conducted 96 daytime studies during the follicular, midluteal, and late luteal phases of the same menstrual cycle in 32 volunteers, aged 40-50 yr (n = 16) and 19-39 yr (n = 16). Mean cycle length was shorter in the older women (26 +/- 0.4 vs. 27.6 +/- 0.6 days; P = 0.02), but mean plasma E2 and P values were similar in the two age groups. Mean plasma FSH was higher in the older group on all 3 study days. For LH, an age difference was observed during the late luteal phase, when mean plasma LH and pulse amplitude were higher in women over 40 yr of age (mean LH, 6.4 +/- 0.7 vs. 3.0 +/- 0.5 IU/L (P = 0.002); mean amplitude, 4.0 +/- 0.5 vs. 2.8 +/- 0.2 IU/L (P = 0.03)]. Pulse frequency was higher in the older group, but not different from that in younger women on all study days. When the subjects aged 35-39 yr were analyzed as a third age group (n = 8), age effects for mean LH persisted, and pulse frequency was higher in the group over 40 yr of age vs. women under age 35 yr (n = 8) in both the follicular phase (7.1 +/- 0.4 us. 5.6 +/- 0.8; P = 0.03) and late luteal phase (5.8 +/- 0.7 vs. 4.4 +/- 0.3; P = 0.03). Although highly variable, individual patterns of gonadotropin secretion in the women over age 40 yr included a sustained elevation in the FSH/LH ratio as well as a failure to demonstrate slow frequency, high amplitude LH pulses in the midluteal phase. In conclusion, 1) the age-related increase in FSH concentrations in ovulatory women, although more pronounced, is associated with phase-dependent enhancement of pulsatile LH secretion; 2) the higher LH concentrations are brought about by changes in both pulse frequency and amplitude; and 3) these age effects preempt overt reductions in cyclic E2 or P concentrations.
为了描述绝经前促性腺激素分泌的差异衰老反应，我们评估了处于月经周期不同阶段的衰老女性的促黄体生成素（LH）脉冲以及促卵泡生成素（FSH）、雌二醇（E2）和孕酮（P）的系列浓度。我们在32名志愿者的同一个月经周期的卵泡期、黄体中期和黄体后期进行了96次日间研究，这些志愿者年龄在40 - 50岁（n = 16）和19 - 39岁（n = 16）。老年女性的平均周期长度较短（26 ± 0.4天 vs. 27.6 ± 0.6天；P = 0.02），但两个年龄组的平均血浆E2和P值相似。在所有3个研究日，老年组的平均血浆FSH均较高。对于LH，在黄体后期观察到年龄差异，40岁以上女性的平均血浆LH和脉冲幅度更高（平均LH，6.4 ± 0.7 vs. 3.0 ± 0.5 IU/L（P = 0.002）；平均幅度，4.0 ± 0.5 vs. 2.8 ± 0.2 IU/L（P = 0.03）]。老年组的脉冲频率较高，但在所有研究日与年轻女性相比无差异。当将35 - 39岁的受试者作为第三个年龄组进行分析时（n = 8），平均LH的年龄效应仍然存在，并且在卵泡期（7.1 ± 0.4 vs. 5.6 ± 0.8；P = 0.03）和黄体后期（5.8 ± 0.7 vs. 4.4 ± 0.3；P = 0.03），40岁以上组的脉冲频率均高于35岁以下组（n = 8）。尽管个体差异很大，但40岁以上女性促性腺激素分泌的个体模式包括FSH/LH比值持续升高，以及在黄体中期未能显示出低频、高幅度的LH脉冲。总之，1）排卵女性中与年龄相关的FSH浓度升高虽然更明显，但与脉冲式LH分泌的时相依赖性增强有关；2）较高的LH浓度是由脉冲频率和幅度的变化共同引起的；3）这些年龄效应先于循环E2或P浓度的明显降低。
