Erisman S, Carnes M, Takahashi L K, Lent S J
Geriatrics Section, William S. Middleton Memorial Veterans Hospital, Madison, WI 53705.
Life Sci. 1990;47(17):1527-33. doi: 10.1016/0024-3205(90)90181-p.
Compared to younger rats, old rats exhibit prolonged elevations of plasma ACTH and corticosterone (CORT) in response to stress. In addition, CORT crosses the placenta. To investigate whether fetuses of older rats may be exposed to higher concentrations of CORT during development than fetuses of young rats, we compared the effects of stress on hypothalamic-pituitary-adrenal (HPA) axis function in young and aging pregnant rats and their 19-day-old fetuses. The plasma of the mothers and fetuses was assayed for ACTH and CORT by radioimmunoassay. Both young and aging pregnant rats showed a significant increase in plasma ACTH and CORT immediately after exposure to stress. However, aging rats had more prolonged elevations of ACTH and CORT than young rats. This suggests that, like old male rats, aging pregnant rats have an alteration in feedback inhibition of the HPA axis. Prolonged elevation of CORT was also seen in fetuses of aging mothers. These results have important implications concerning the effects of stress during pregnancy at different maternal ages, and for the potential deleterious consequences of prolonged prenatal elevation in stress hormones on the offspring of aging females.
与年轻大鼠相比，老年大鼠对应激的反应表现为血浆促肾上腺皮质激素（ACTH）和皮质酮（CORT）水平持续升高。此外，CORT可穿过胎盘。为了研究老年大鼠的胎儿在发育过程中是否比年轻大鼠的胎儿暴露于更高浓度的CORT，我们比较了应激对年轻和老龄怀孕大鼠及其19日龄胎儿下丘脑-垂体-肾上腺（HPA）轴功能的影响。通过放射免疫分析法检测母体和胎儿血浆中的ACTH和CORT。年轻和老龄怀孕大鼠在暴露于应激后，血浆ACTH和CORT均显著增加。然而，老年大鼠的ACTH和CORT升高持续时间比年轻大鼠更长。这表明，与老年雄性大鼠一样，老龄怀孕大鼠的HPA轴反馈抑制存在改变。老龄母体的胎儿中也观察到CORT持续升高。这些结果对于不同母体年龄怀孕期应激的影响，以及应激激素产前长期升高对老龄雌性后代潜在的有害后果具有重要意义。
