Chronic stress is related to the acceleration of telomere shortening. Recent work showed a correlation between chronic psychosocial stress and reduced telomere length in certain cells. The exposure of T lymphocytes to cortisol promoted a significant reduction in telomerase activity. Although stress can promote changes in telomere length, whether increased glucocorticoid concentrations alter telomere length in brain tissue cells is unclear. In addition to modulating the activity of the stress system, estrogen also influences telomere length. The objective of this study was to verify whether chronic exposure to glucocorticoids promotes changes in the telomere length of encephalic areas involved in the control of HPA axis activity and whether estrogen affects these changes. Wistar rats were ovariectomized and treated with estradiol cypionate [(50 or 100 μg/kg, subcutaneously)] or oil and 20 mg/kg corticosterone or vehicle (isotonic saline with 2% Tween 80, subcutaneously) for 28 days. On the day after the end of the hormonal treatment, the animals were euthanized for collection of blood, brain and pituitary gland samples. Estrogen modulated the activity of the HPA axis. CRH, AVP and POMC mRNA levels were reduced by estrogen. At least in doses and treatment time used, there was no correlation between effects of exposure to glucocorticoids and estrogen on telomere length in the brain areas of female rats. However, estrogen treatment reduced the telomere length in the central amygdala and dorsal hippocampus, but not in the PVN, indicating a variation of reaction of telomeres for estrogen in different brain areas.

慢性压力与端粒缩短的加速有关。最近的研究表明，慢性心理社会压力与某些细胞中端粒长度缩短之间存在相关性。T 淋巴细胞与皮质醇的接触促进了端粒酶活性的显着降低。尽管压力可以促进端粒长度的变化，但糖皮质激素浓度的增加是否会改变脑组织细胞中的端粒长度尚不清楚。除了调节压力系统的活动外，雌激素还会影响端粒长度。本研究的目的是验证长期接触糖皮质激素是否会促进参与控制 HPA 轴活动的脑区端粒长度的变化，以及雌激素是否会影响这些变化。Wistar 大鼠切除卵巢并用环戊丙酸雌二醇 [（50 或 100 μg/kg，皮下注射）] 或油和 20 mg/kg 皮质酮或载体（含 2% Tween 80 的等渗盐水，皮下注射）治疗 28 天。在激素治疗结束后的第二天，将动物安乐死以收集血液、脑和垂体腺样本。雌激素调节 HPA 轴的活动。CRH、AVP 和 POMC mRNA 水平被雌激素降低。至少在使用的剂量和治疗时间方面，暴露于糖皮质激素和雌激素对雌性大鼠脑区端粒长度的影响之间没有相关性。然而，雌激素治疗减少了中央杏仁核和背侧海马的端粒长度，但在 PVN 中没有，表明端粒对不同脑区的雌激素反应存在差异。