Oxidative activites of liver mitochondria from mammals, birds, reptiles and amphibia as a function of temperature

1. 1. Liver mitochondria of the toad (Bufo viridis), the common lizard (Agama stellio), the domestic fowl (Gallus domesticus) and the hamster (Mesocricetus auratus) were isolated. 2. 2. Their oxygen consumption rates with succinate plus glutamate as substrates were measured with an oxygen electrode at ambient temperatures between 18-55°C. 3. 3. Arrhenius plots of the relationship between activity and ambient temperatures showed linear regression curves with similar slopes. 4. 4. It is therefore suggested that, in principle, oxidative reactions brought about by the mitochondria are probably of common origin in the four species studied. 5. 5. The nature of the activation energy of the oxidative reactions may explain the primary damage caused in higher organisms by heat stroke.