Improved cardiac performance after ischemia in aged rats supplemented with vitamin E and alpha-lipoic acid.
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 < 0.05) in ANTIOX animals compared with CON diet animals. I-R resulted in a significant increase (P < 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 < 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.
Coombes
J S
JS
Center for Exercise Science, University of Florida, Gainesville, Florida 32611, USA. jcoombes@hms.uq.edu.au
Powers
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Hamilton
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Demirel
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Shanely
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Sen
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D000818:Animals; D000975:Antioxidants / Q000008:administration & dosage / Q000494:pharmacology*; D001794:Blood Pressure / Q000187:drug effects; D019587:Dietary Supplements; D006321:Heart / Q000187:drug effects / Q000502:physiology / Q000503:physiopathology*; D015227:Lipid Peroxidation / Q000187:drug effects*; D008297:Male; D017202:Myocardial Ischemia / Q000188:drug therapy / Q000503:physiopathology*; D015425:Myocardial Reperfusion; D009206:Myocardium / Q000378:metabolism; D051381:Rats; D011916:Rats, Inbred F344; D008063:Thioctic Acid / Q000008:administration & dosage / Q000494:pharmacology*; D014810:Vitamin E / Q000008:administration & dosage / Q000494:pharmacology*
D000975:Antioxidants; D014810:Vitamin E; D008063:Thioctic Acid