title: Suppressive effect of coenzyme Q10 on phospholipase A2 activation in cardiac cells after prolonged swimming.
abstract: Phospholipase A2 (PLA2) activity is elevated in cardiac microsomal fractions and phospholipids (PL) are much reduced in both the cardiac mitochondria and microsomal fractions from rats subjected to prolonged swimming. Preadministration of coenzyme Q10 (CoQ10 i.v. 30 mg/kg) significantly suppressed these changes. Two groups of 8-week-old male Wistar rats were trained to swim, receiving 30 min of training for 4 days. On the fifth day they were given an intravenous injection of either 30 mg/kg CoQ10 in saline or 1 ml saline. Thirty minutes later they began to swim for 3 hours carrying a weight representing 3% of body weight. On completion of the swim they were sacrified by instantaneous decapitation, and cardiac mitochondria were isolated. Mitochondria were also prepared from saline injected, unexercised control rats. Phosphatidylethanolamine (PE) and phosphatidylcholine (PC) concentrations were measured with HPLC and PLA2 activity was assayed fluorometrically. The mitochondrial concentrations (means +/- SEM, n = 6) of PE and PC were respectively 126 +/- 22 and 140 +/- 22 nmol/mg protein in the exercise-CoQ10 group against 66 +/- 4 and 50 +/- 10 nmol/mg protein in the exercise-saline group. The specific PLA2 activities (expressed as nmol degraded dipyrene phosphorylethanolamine substrate/hr/mg protein) in the microsomes was 0.20 +/- 0.02 in the exercise-CoQ10 group against 0.30 +/- 0.02 in the exercise-saline group. These results suggest CoQ10 has a protective effect against an excessive reduction in mitochondrial membrane phospholipids during prolonged exercise.
authors.affiliation: Research Institute of Applied Electricity, Hokkaido University, Sapporo, Japan.
authors.forename: T
authors.initials: T
authors.lastname: Koyama
authors.forename: W
authors.initials: W
authors.lastname: Keatisuwan
authors.forename: M
authors.initials: M
authors.lastname: Kinjo
authors.forename: H
authors.initials: H
authors.lastname: Saito
mesh_terms: D000818:Animals; D003067:Coenzymes; D004789:Enzyme Activation / Q000187:drug effects; D006321:Heart / Q000187:drug effects; D008297:Male; D008861:Microsomes / Q000187:drug effects / Q000201:enzymology / Q000378:metabolism; D008929:Mitochondria, Heart / Q000187:drug effects* / Q000201:enzymology; D009206:Myocardium / Q000201:enzymology* / Q000378:metabolism; D010713:Phosphatidylcholines / Q000378:metabolism; D010714:Phosphatidylethanolamines / Q000378:metabolism; D010741:Phospholipases A / Q000378:metabolism*; D054467:Phospholipases A2; D005082:Physical Exertion; D051381:Rats; D011919:Rats, Inbred Strains; D013550:Swimming; D014451:Ubiquinone / Q000031:analogs & derivatives* / Q000494:pharmacology
chemical_list: D003067:Coenzymes; D010713:Phosphatidylcholines; D010714:Phosphatidylethanolamines; D014451:Ubiquinone; D010741:Phospholipases A; D054467:Phospholipases A2; C024989:coenzyme Q10