Improved cardiac performance after ischemia in aged rats supplemented with vitamin E and [Alpha]-lipoic acid

Coombes, Jeff S., Scott K. Powers, Karyn L. Hamilton, Haydar A. Demirel, R. Andrew Shanely, Murat A. Zergeroglu, Chandan K. Sen, Lester Packer, and Li Li Ji. Improved cardiac performance after ischemia in aged rats supplemented with vitamin E and [Alpha]-lipoic acid. Am J Physiol Regulatory Integrative Comp Physiol 279: R2149-R2155, 2000.--The purpose of these experiments was to examine the effects of dietary antioxidant supplementation with vitamin E (VE) and [Alpha]-lipoic acid ([Alpha]-LA) on biochemical and physiological responses to in vivo myocardial ischemia-reperfusion (I-R) in aged rats. Male Fischer-334 rats (18 mo old) were assigned to either 1) a control diet (CON) or 2) a VE and [Alpha]-LA supplemented diet (ANTIOX). After a 14-wk feeding period, animals in each group underwent an in vivo I-R protocol (25 min of myocardial ischemia and 15 min of reperfusion). During reperfusion, peak arterial pressure was significantly higher (P [is less than] 0.05) in ANTIOX animals compared with CON diet animals. I-R resulted in a significant increase (P [is less than] 0.05) in myocardial lipid peroxidation in CON diet animals but not in ANTIOX animals. Compared with ANTIOX animals, heart homogenates from CON animals experienced significantly less (P [is less than] 0.05) oxidative damage when exposed to five different in vitro radical producing systems. These data indicate that dietary supplementation with VE and [Alpha]-LA protects the aged rat heart from I-R-induced lipid peroxidation by scavenging numerous reactive oxygen species. Importantly, this protection is associated with improved cardiac performance during reperfusion. aging; free radicals; lipid peroxidation; myocardial performance