The effects of exercise duration on adrenal HSP72/73 induction in rats
Abstract:This study investigated the effects of varying durations of exercise training on heat shock proteins 72 and 73 (HSP72/73) induction in the rat adrenal gland. Female Sprague–Dawley rats (120 days old) were assigned to either a sedentary control group (C) or one of the three endurance exercise training groups. Trained animals ran on a treadmill at ≈75% VO2max for 10 weeks (4–5 days week–1) at one of the three different exercise durations (30 min day–1=T30, 60 min day–1=T60, or 90 min day–1=T90). All durations of exercise training resulted in an increase in the HSP72 levels (P < 0.0001). The magnitude of the training-induced elevation in the HSP72 levels in the adrenal gland increased as a function of the training duration (≈60-fold increase in T90; ≈40-fold increase in T60; and ≈15-fold increase in T30). Longer exercise durations (>60 min day–1), also resulted in small but significant increase in HSP73 level (≈1.2-fold increase in both T60 and T90; P < 0.05). These results demonstrate that the physiological stress created by chronic treadmill running can induce both HSP72 and HSP73 in rat adrenal gland. Increased levels of adrenal HSP72/73 expression during rigorous exercise, may be one of the adaptive mechanisms of the adrenals to cope with an increased dose of stress.
Document Type: Research Article
Affiliations: Departments of Exercise and Sport Sciences, Physiology, and Pharmacology. Center for Exercise Science, and Geriatric Research, Education and Clinical Center, VA Medical Center, University of Florida, Gainesville, FL, USA
Publication date: November 1, 1999