Master of Science
Dr. Jim Staples
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 respiration rates of mitochondria treated with palmitoyl CoA, nor did it increase the respiration rate of torpid mitochondria. Though palmitoyl CoA inhibits succinate-fuelled respiration, suppression may not be exclusively related to inhibition of succinate transport at the DCT, and is likely inhibiting additional mitochondrial transporters such as the adenine-nucleotide transporter.
Cooper, Alex, "Are long chain acyl CoAs responsible for suppression of mitochondrial metabolism in hibernating 13-lined ground squirrels?" (2013). Electronic Thesis and Dissertation Repository. 1372.