Exercise training provides cardioprotection against ischemia-reperfusion induced apoptosis in young and old animals.
Endurance exercise provides cardioprotection against ischemia-reperfusion (IR)-induced necrotic cell death in young animals. However, whether exercise-induced cardioprotection prevents IR-induced apoptosis in young and old animals is unknown. We tested the hypothesis that endurance exercise training will attenuate IR-induced myocardial apoptosis in young (4 months) and old (24 months) male F344 rats. Young and old rats remained sedentary or performed multiple bouts of moderate intensity running exercise. To induce apoptosis, isolated working hearts were exposed to 45 min of ischemia followed by 90 min of reperfusion. Assessment of myocardial levels of caspase-3 cleaved alpha-spectrin and TUNEL labeled nuclei revealed that IR resulted in apoptosis in hearts from both young and old animals. Importantly, independent of age, exercise attenuated the IR-induced apoptosis of cardiac myocytes. Moreover, exercise attenuated IR-induced calpain activation in the hearts of both young and old animals. These experiments for the first time demonstrate that exercise attenuates IR-induced myocardial apoptosis in both young and old animals. Potential mechanisms for this exercise-induced cardioprotection against IR-induced apoptosis include improved myocardial antioxidant capacity and prevention of calpain and caspase-3 activation.
Quindry
John
J
Department of Applied Physiology and Kinesiology, Center for Exercise Science, University of Florida, P.O. Box 118206, Gainesville, FL 32611, USA. jquindry@ufl.edu
French
Joel
J
Hamilton
Karyn
K
Lee
Youngil
Y
Mehta
Jawahar L
JL
Powers
Scott
S
D000375:Aging / Q000502:physiology*; D000818:Animals; D000975:Antioxidants / Q000378:metabolism; D017209:Apoptosis / Q000502:physiology*; D015153:Blotting, Western / Q000379:methods; D002154:Calpain / Q000378:metabolism; D004249:DNA Damage / Q000502:physiology; D006321:Heart / Q000503:physiopathology; D020287:In Situ Nick-End Labeling / Q000379:methods; D007511:Ischemia / Q000503:physiopathology; D008297:Male; D015428:Myocardial Reperfusion Injury / Q000503:physiopathology / Q000517:prevention & control*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D011916:Rats, Inbred F344; D015424:Reperfusion / Q000379:methods
D000975:Antioxidants; D002154:Calpain