ISSN:
1432-136X
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Medicine
Notes:
Summary 1. The thermal response of liver and heart mitochondrial succinate oxidase and succinate cytochromec reductase of eleven homeothermic and six heterothermic species was compared. 2. Arrhenius plots of succinate oxidase and succinate cytochromec reductase of homeotherms exhibited a meanT * (Arrhenius critical temperature) of 22.6 °C. In normothermic heterothermsT * occurred at a mean temperature of 20.1 °C. During the season in which they entered torpor, two of the heterothermic mammals exhibited a meanT * at 10.9 °C, whilst for three species noT * was observed in the temperature range 5 °C to 40 °C. 3. The loweredT * in the heterothermic species was accompanied by an increase in theE a and Q10 both above and below the discontinuity in the Arrhenius plot. The increase Q10 of the mitochondrial enzymes isolated from animals during torpor was identical to the Q10 for O2 consumption for animals entering torpor. This may represent an important factor for energy conservation during torpor.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00688801
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