Dietary fat type and regular exercise affect mitochondrial composition andfunction depending on specific tissue in the rat

Physical exercise and fatty acids have been studied in relation to mitochon drial composition and function in rat liver, heart, and skeletal muscle. Ma le rats were divided into two groups according to dietary fat type (virgin olive and sunflower oils). One-half of the animals from each group were sub jected to a submaximal exercise for 8 weeks; the other half acted as sedent ary controls. Coenzyme Q, cytochromes b, c + c(1), a + a(3) concentrations, and the activity of cytochrome c oxidase were determined. Regular exercise increased (P < 0.05) the concentration of the above-mentioned elements and the activity of the cytochrome c oxidase by roughly 50% in liver and skele tal muscle. In contrast, physical exercise decreased (P c 0.05) cytochrome c oxidase activity in the heart (in mu mol/min/g, from 8.4 +/- 0.1 to 4.9 /- 0.1 in virgin olive oil group and from 9.7 +/- 0.1 to 6.7 +/- 0.2 in sun flower oil animals). Dietary fat type raised the levels of coenzyme Q, cyto chromes, and cytochrome c oxidase activity in skeletal muscle (P < 0.05) am ong the rats fed sunflower oil. In conclusion, dietary fat type, regular ex ercise, and the specific tissue modulate composition and function of rat mi tochondria.