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Full-Text Articles in Life Sciences
Are Long Chain Acyl Coas Responsible For Suppression Of Mitochondrial Metabolism In Hibernating 13-Lined Ground Squirrels?, Alex Cooper
Electronic Thesis and Dissertation Repository
I found 44% suppression of succinate-fuelled liver mitochondrial respiration in torpid 13-lined ground squirrels compared to interbout euthermia (IBE). Palmitoyl CoA, predicted to suppress respiration by inhibiting succinate transport at the dicarboxylate transporter (DCT), reduced respiration by ~70%, while butylmalonate, a known inhibitor of the DCT, only inhibited respiration by ~40%. In both cases inhibition of respiration proportionally affected both torpid and IBE mitochondria, suggesting that the DCT is likely not already inhibited in torpid mitochondria. The addition of carnitine, predicted to reverse suppression by facilitating transport of palmitoyl CoA into the mitochondrial matrix, had no rescuing effect on the …
Regulation Of Succinate-Fuelled Mitochondrial Respiration In Liver And Skeletal Muscle Of Hibernating Thirteen-Lined Ground Squirrels., Jason C L Brown, Dillon J Chung, Alex N Cooper, James F Staples
Regulation Of Succinate-Fuelled Mitochondrial Respiration In Liver And Skeletal Muscle Of Hibernating Thirteen-Lined Ground Squirrels., Jason C L Brown, Dillon J Chung, Alex N Cooper, James F Staples
Biology Publications
Hibernating ground squirrels (Ictidomys tridecemlineatus) alternate between two distinct metabolic states throughout winter: torpor, during which metabolic rate (MR) and body temperature (Tb) are considerably suppressed, and interbout euthermia (IBE), during which MR and Tb briefly return to euthermic levels. Previous studies showed suppression of succinate-fuelled respiration during torpor in liver and skeletal muscle mitochondria; however, these studies used only a single, saturating succinate concentration. Therefore, they could not address whether mitochondrial metabolic suppression occurs under physiological substrate concentrations or whether differences in the kinetics of mitochondrial responses to changing substrate concentration might also contribute to mitochondrial metabolic regulation during …
Metabolism Of Brain Cortex And Cardiac Muscle Mitochondria In Hibernating 13-Lined Ground Squirrels Ictidomys Tridecemlineatus., Kirsten Gallagher, James F Staples
Metabolism Of Brain Cortex And Cardiac Muscle Mitochondria In Hibernating 13-Lined Ground Squirrels Ictidomys Tridecemlineatus., Kirsten Gallagher, James F Staples
Biology Publications
During bouts of torpor, mitochondrial metabolism is known to be suppressed in the liver and skeletal muscle of hibernating mammals. This suppression is rapidly reversed during interbout euthermic (IBE) phases, when whole-animal metabolic rate and body temperature (T(b)) return spontaneously to euthermic levels. Such mitochondrial suppression may contribute significantly to energy savings, but the capacity of other tissues to suppress mitochondrial metabolism remains unclear. In this study we compared the metabolism of mitochondria from brain cortex and left ventricular cardiac muscle between animals sampled while torpid (stable T(b) near 5°C) and in IBE (stable T(b) near 37°C). Instead of isolating …