[The correlation of liver mitochondrial respiration in mammals and reptiles at different temperatures]

In the experiments with isolated mitochondria in vitro (25 degrees C) it was shown that the respiration rate in mice was 3-5 times higher compared with agamas; in this case both animal species exhibited close body mass. At the comparison of mice and tortoises with the body mass 25-30 times exceeding the one of mice 4-10 times difference in mitochondrial respiration was found. In addition this difference was more pronounced with caprilate and pyruvate than with succinate used as substrates. High rates of respiration for mice mitochondria are shown to persist at wide temperature range in vitro. However respiration parameters for mice and agamas are close in vitro at the temperature of 37 degrees C for mice mitochondria (the optimal mouse body temperature is about 37 degrees C) and the temperature of 42 degrees C for agama mitochondria (the optimal life temperature for agamas is about 42 degrees C).