Restrepo C, Armario A
Departamento de Biologia Celular y Fisiología, Facultad de Ciencias, Universidad Autónoma de Barcelona, Bellaterra, Spain.
Psychoneuroendocrinology. 1987;12(5):393-8. doi: 10.1016/0306-4530(87)90068-0.
The effect of exposure to chronic stress on the pituitary-adrenal axis was studied in prepubertal rats. The chronic stress consisted of exposing the animals 6 days a week for 32 days to one stressor randomly chosen among several each day. Chronic stress did not alter either food intake or body weight gain. However, it was stressful for the rats, as they had increased adrenal weights. Chronically stressed rats showed normal pituitary-adrenal basal activity and normal ACTH responses to a novel, acutely applied stressor. However, this treatment resulted in higher corticosterone response to an acute stressor, as a consequence of enhanced adrenocortical response to ACTH. In addition, chronic stress induced increasing sensitivity of the adrenal to the inhibitory action of dexamethasone. Exploratory activity and defecation rate in a novel environment were not affected by the chronic stress. All these data indicate that behavioral and endocrine changes induced by chronic stress were somewhat different from those previously found in adult rats. Prepubertal rats appear to be less sensitive than adult rats to the chronic stress we used.
在青春期前大鼠中研究了慢性应激暴露对垂体 - 肾上腺轴的影响。慢性应激包括每周6天、持续32天让动物每天随机接触几种应激源中的一种。慢性应激既未改变食物摄入量，也未改变体重增加。然而，这对大鼠来说是有压力的，因为它们的肾上腺重量增加了。长期应激的大鼠表现出正常的垂体 - 肾上腺基础活性以及对新的急性施加的应激源的正常促肾上腺皮质激素（ACTH）反应。然而，由于肾上腺皮质对ACTH的反应增强，这种处理导致对急性应激源的皮质酮反应更高。此外，慢性应激导致肾上腺对地塞米松抑制作用的敏感性增加。在新环境中的探索活动和排便率不受慢性应激的影响。所有这些数据表明，慢性应激引起的行为和内分泌变化与先前在成年大鼠中发现的有所不同。青春期前大鼠似乎比成年大鼠对我们使用的慢性应激更不敏感。
