부산대학교 도서관

Glucocorticoids (GCs) are released by the hypothalamic-pituitary-adrenal (HPA) axis in response to a variety of stressors. Although acute elevations of GCs are beneficial, prolonged exposure has significant and detrimental metabolic consequences, most notably seen in Cushing's syndrome. Here, we created an animal model of Cushing's syndrome and investigated the impact of exercise training on various metabolic parameters. Male Sprague-Dawley rats were divided into exercise and sedentary groups and further subdivided into control (SHAM) and corticosterone (CORT) groups. Exercising animals had access to running wheels for 6 weeks, while sedentary animals remained in standard cages. A 300mg corticosterone pellet was implanted subcutaneously in CORT rats while SHAM rats received a wax pellet. Within 1 week, both sedentary and exercising CORT rats demonstrated a ≈15-and 1.7-fold elevation in nadir and peak GCs levels respectively, resulting in an abolished diurnal pattern. Relative to body weight, sedentary CORT animals had more epididymal fat when compared to sedentary controls. Conversely, exercise CORT rats had epididymal fat content comparable to that of exercise SHAM animals. This study proposes a new animal model of Cushing's syndrome and reveals that regular exercise attenuates the accumulation of visceral fat mass in this animal model. This study was funded by NSERC. [ABSTRACT FROM AUTHOR]