Effects of treadmill exercise on hypoactivity of the hypothalamo-pituitary-adrenal axis induced by chronic administration of corticosterone in rats

• Published in: Neuroscience letters 2008-03, Vol.434 (1), p.46-49
• Main Authors: Kim, Hong Gi, Lim, Eun Young, Jung, Woo Ram, Shin, Min Kyoo, Ann, Eue Soo, Kim, Kil Lyong
• Format: Article
• Language: English
• Subjects: ACTH; Adrenocorticotropic Hormone - metabolism; Adrenocorticotropic Hormone - secretion; Animals; Biological and medical sciences; Chronic Disease - therapy; Corticosterone; Corticosterone - administration & dosage; Corticosterone - metabolism; Corticosterone - secretion; Corticotropin-Releasing Hormone - genetics; CRF; Disease Models, Animal; Drug Administration Schedule; Exercise Test; Exercise Therapy - methods; Fundamental and applied biological sciences. Psychology; HPA axis; Hypothalamo-Hypophyseal System - drug effects; Hypothalamo-Hypophyseal System - metabolism; Hypothalamo-Hypophyseal System - physiopathology; Male; Physical Conditioning, Animal - methods; Pituitary Diseases - chemically induced; Pituitary Diseases - physiopathology; Pituitary Diseases - therapy; Pituitary-Adrenal System - drug effects; Pituitary-Adrenal System - metabolism; Pituitary-Adrenal System - physiopathology; Rats; Rats, Sprague-Dawley; RNA, Messenger - drug effects; RNA, Messenger - metabolism; Stress, Psychological - complications; Treadmill exercise; Treatment Outcome; Vertebrates: nervous system and sense organs
• ISSN: 0304-3940; 1872-7972
• DOI: 10.1016/j.neulet.2008.01.025

The stress response alters behavior, autonomic function and secretion of multiple hormones, including CRF, ACTH, and glucocorticoid, through the HPA axis. Consecutive stress exposures lead to HPA axis dysregulation such as hyperactivity in Alzheimer's disease and depression, and hypoactivity in post-traumatic stress disorder. In the present study, we established a model of hypoactivated HPA axis in rat through chronic administration of corticosterone (40 mg/kg, s.c.) for 19 consecutive days. In this model, CRF mRNA expression in the hypothalamus and ACTH levels in serum were significantly decreased by chronic administration of corticosterone. In addition, the effect of treadmill exercise was investigated in our hypoactivated HPA axis rat model. Treadmill exercise recovered the dysregulated hypoactivity of the HPA axis induced by corticosterone administration for 19 days. The results of the present study suggest that treadmill exercise may aid recovery of hypoactivated HPA axis dysregulation in psychological diseases such as post-traumatic stress disorder.