Comparative functional properties of mitochondria from seal and dog hearts.
The harbor seal (Phoca vitulina) is capable of protracted dives resulting in low arterial PO2 levels. The mammalian heart is an aerobic organ depending primarily on mitochondrial oxidations for energy (ATP). Heart mitochondria were isolated from freshly killed seals and the functional data obtained compared to dog heart mitochondria isolated under similar conditions. The percentage yields of mitochondria based on cytochrome oxidase recovery were essentially the same from dog and seal hearts. However, the actual quantity of mitochondrial protein obtained per gram of seal heart tissue was lower than that isolated from dog heart. Phosphorylating rates of respiration (State 3; Q02) and cytochrome content were significantly lower in seal heart mitochondria compared to dog. The data indicate that seal hearts have fewer mitochondria per gram of tissue, lower active respiratory rates and lower cytochrome contents than dog heart.
D000818:Animals; D003580:Cytochromes / Q000378:metabolism; D004285:Dogs; D003576:Electron Transport Complex IV; D008929:Mitochondria, Heart / Q000378:metabolism*; D010085:Oxidative Phosphorylation; D010101:Oxygen Consumption; D046048:Seals, Earless
D003580:Cytochromes; D003576:Electron Transport Complex IV