The effects of glucagon on hepatic mitochondrial metabolism in the pigeon, Columba livia.
The effects of glucagon infusion on substrate oxidation by liver mitochondria from the pigeon, Columba livia, were examined. While the response of mammalian liver mitochondria to glucagon involves elevated rates of oxidation of succinate, pyruvate, alpha-ketoglutarate, glutamate, and acyl carnitines, avian hepatic mitochondria demonstrate no change in state 3 rates for the oxidation of succinate, pyruvate, alpha-ketoglutarate, and glutamate upon glucagon infusion. There was a trend toward decreasing the state 3 rate of oxidation of long-chain acyl carnitines compared to other substrates with glucagon treatment. State 4 rates of oxidation of all substrates including acyl carnitines were unaffected by glucagon infusion. The permeability of pigeon liver mitochondria to NADH was not affected by glucagon infusion, indicating no change in the fragility of the mitochondria. The effect of glucagon in elevating oxidation of lipids in mammals and decreasing oxidation in birds correlates with its hyperlipemic action in birds and the hypolipemic action in mammals.
Ballantyne
J S
JS
Department of Zoology, University of Guelph, Ontario, Canada.
John
T M
TM
George
J C
JC
D000818:Animals; D010856:Columbidae / Q000378:metabolism*; D005260:Female; D005934:Glucagon / Q000494:pharmacology*; D008297:Male; D008930:Mitochondria, Liver / Q000187:drug effects / Q000378:metabolism*; D010084:Oxidation-Reduction / Q000187:drug effects; D010101:Oxygen Consumption / Q000187:drug effects
D005934:Glucagon