Welt C K, Jimenez Y, Sluss P M, Smith P C, Hall J E
Reproductive Endocrine Unit, Department of Medicine, Massachusetts General Hospital, Boston, MA 02114, USA.
Hum Reprod. 2006 Aug;21(8):2189-93. doi: 10.1093/humrep/del136. Epub 2006 May 9.
Estradiol (E(2)) concentration is preserved in older reproductive-aged women despite a decrease in follicle number and androstenedione (AD) levels. We hypothesized that increased aromatase activity accounts for E(2) preservation in older women.
Older (36-46 years; n = 11) and younger (21-35 years; n = 10) women with 25- to 35-day menstrual cycles participated in a parallel design study. Daily blood samples were drawn starting at menses, and recombinant human FSH (rhFSH), 150 IU, was administered when the dominant follicle's diameter was > or =16 mm. FSH, LH, E(2), estrone (E(1)), AD and the AD/E(1) ratio were compared.
E(2) and E(1) concentrations and the E(1)/E(2) ratio were similar across the follicular phase in older compared with younger women, whereas AD and the AD/E(1) ratio were lower. Older women had higher FSH concentrations in the early follicular phase and fewer small follicles. RhFSH-stimulated changes in E(1) were similar between older and younger subjects despite the smaller number of follicles.
These findings suggest that E(2) secretion is maintained by increased aromatase function in older compared with younger reproductive-aged women, whereas there is no apparent difference in 17beta-hydroxysteroid dehydrogenase activity. The increased aromatase is probably driven by increased FSH in the early follicular phase and compensates for the decreased follicle number in older reproductive-aged women.
尽管卵泡数量和雄烯二酮（AD）水平下降，但老年育龄妇女的雌二醇（E₂）浓度仍保持不变。我们推测芳香化酶活性增加是老年女性E₂浓度保持的原因。
月经周期为25至35天的老年（36 - 46岁；n = 11）和年轻（21 - 35岁；n = 10）女性参与了一项平行设计研究。从月经开始每日采集血样，当优势卵泡直径≥16 mm时，给予重组人促卵泡激素（rhFSH）150 IU。比较促卵泡激素（FSH）、促黄体生成素（LH）、E₂、雌酮（E₁）、AD以及AD/E₁比值。
与年轻女性相比，老年女性在卵泡期的E₂和E₁浓度以及E₁/E₂比值相似，而AD和AD/E₁比值较低。老年女性在卵泡早期FSH浓度较高，小卵泡较少。尽管卵泡数量较少，但rhFSH刺激后老年和年轻受试者E₁的变化相似。
这些发现表明，与年轻育龄女性相比，老年女性芳香化酶功能增强维持了E₂分泌，而17β - 羟类固醇脱氢酶活性无明显差异。早期卵泡期FSH增加可能驱动芳香化酶增加，从而补偿老年育龄女性卵泡数量的减少。
