The effects of exercise duration on adrenal HSP72/73 induction in rats.
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 approximately 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 ( approximately 60-fold increase in T90; approximately 40-fold increase in T60; and approximately 15-fold increase in T30). Longer exercise durations (>60 min day-1), also resulted in small but significant increase in HSP73 level ( approximately 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.
Demirel
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Department of Exercise and Sport Sciences, VA Medical Center, University of Florida, Gainesville, FL, USA.
Powers
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Naito
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Tumer
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D000222:Adaptation, Physiological; D000311:Adrenal Glands / Q000378:metabolism* / Q000473:pathology; D000818:Animals; D015153:Blotting, Western; D001835:Body Weight; D002352:Carrier Proteins / Q000096:biosynthesis*; D005260:Female; D050883:HSC70 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins / Q000096:biosynthesis*; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins / Q000096:biosynthesis*; D009929:Organ Size; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
D002352:Carrier Proteins; D050883:HSC70 Heat-Shock Proteins; D018840:HSP70 Heat-Shock Proteins; D050884:HSP72 Heat-Shock Proteins; D006360:Heat-Shock Proteins; C494373:Hspa8 protein, rat