title: Effects of dietary protein and fat level on oxidative phosphorylation in rat heart mitochondria.
abstract: The effect of dietary protein and fat levels on cardiac mitochondrial oxidative phosphorylation was assessed polarographically. Weanling rats were fed on semi-purified diets containing different protein levels (10, 30, 50 and 70%) on a gross energy basis (PGE) for 9, 23 and 58 d. Cardiac mitochondria isolated from rats fed on a 70% PGE diet for 23 d exhibited significantly reduced ADP:oxygen (ADP:O) values compared with mitochondria from rats fed on a low-protein diet. Feeding low-protein diets for 58 d increased the ADP: O value. When the dietary fat level was altered to provide (% PGE: % fat-energy): 30:14, 30:30, 70:14, 70:30, feeding 70% PGE diets reduced the ADP:O value compared with the 30% PGE level, but no difference was observed between low-fat and high-fat groups. These results indicate that the impaired ADP: O value for rats fed on very-high-protein diets was not due to the dietary fat level but that the level of dietary protein is an important determinant of oxidative phosphorylation in rat heart mitochondria.
authors.affiliation: Department of Foods & Nutrition, University of Alberta, Edmonton, Canada.
authors.forename: M
authors.initials: M
authors.lastname: Toyomizu
authors.forename: M T
authors.initials: MT
authors.lastname: Clandinin
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D000818:Animals; D004041:Dietary Fats / Q000008:administration & dosage*; D004044:Dietary Proteins / Q000008:administration & dosage*; D008297:Male; D008929:Mitochondria, Heart / Q000187:drug effects / Q000378:metabolism*; D010085:Oxidative Phosphorylation / Q000187:drug effects; D010101:Oxygen Consumption; D051381:Rats; D017207:Rats, Sprague-Dawley; D013997:Time Factors
chemical_list: D004041:Dietary Fats; D004044:Dietary Proteins; D000244:Adenosine Diphosphate