Endurance exercise training inhibits activity of plasma GOT and liver caspase-3 of mice [correction of rats] exposed to stress by induction of heat shock protein 70.
A single bout of exercise increases production of heat shock protein 70 (HSP70), which protects cells against various stresses. In this study, we investigated whether endurance exercise training enhances liver level of HSP70 and, if so, whether HSP70 contributes to hepatic protection against stress in vivo. Mice of an exercise-training group performed 60 min of treadmill running 5 days/wk for 4 wk. The resting level of liver HSP70 was 4.5 times higher in the trained than in sedentary mice. After 4 wk of exercise training, both groups of mice were exposed to the following stresses: 1) heat stress, 2) cold stress, 3) oxidative stress, 4) ethanol stress, and 5) exercise stress by compelling the mice to run on a treadmill until exhausted. After exposure to the stresses, the liver was immediately isolated. Elevation of liver HSP70 in the trained mice was evident, whereas no elevation was found in the sedentary mice. On exposure to heat, diethyldithiocarbamate and ethanol, activities of glutanic oxalacetic transaminase in plasma, and liver caspase-3, a key enzyme of apoptotic processing, were elevated in the sedentary mice but not in the trained mice. These results suggest that exercise training enhanced the resting level of liver HSP70 and hepatic protection against various stresses, at least partly attributing to the suppression of caspase-3 activity by the increase in HSP70.
Mikami
Toshio
T
Department of Health and Sports Science, Nippon Medical School, 2-297-2 Kosugi-cho, Nakahara-ku, Kawasaki, Kanagawa 211-0063, Japan. mikami@nms.ac.jp
Sumida
Satoshi
S
Ishibashi
Yoshitomo
Y
Ohta
Shigeo
S
D000222:Adaptation, Physiological; D000818:Animals; D001219:Aspartate Aminotransferases / Q000097:blood*; D001831:Body Temperature; D053148:Caspase 3; D020169:Caspases / Q000378:metabolism*; D018840:HSP70 Heat-Shock Proteins / Q000378:metabolism*; D008099:Liver / Q000201:enzymology / Q000378:metabolism*; D008297:Male; D051379:Mice; D008813:Mice, Inbred ICR; D010805:Physical Conditioning, Animal / Q000502:physiology*; D010807:Physical Endurance; D011897:Random Allocation; D012007:Rectum / Q000503:physiopathology; D012146:Rest; D013312:Stress, Physiological / Q000097:blood / Q000209:etiology / Q000378:metabolism*
D018840:HSP70 Heat-Shock Proteins; D001219:Aspartate Aminotransferases; C505409:Casp3 protein, mouse; D053148:Caspase 3; D020169:Caspases