Restoration of the properties of carnitine palmitoyltransferase I in liver mitochondria during re-feeding of starved rats.

The recovery of the parameters of the kinetic properties of carnitine palmitoyltransferase (CPT) I in liver mitochondria of starved rats was studied after re-feeding animals for various periods of time. There were no significant changes either in the activity of the enzyme at high palmitoyl-CoA concentrations or in the affinity of the enzyme for palmitoyl-CoA, or in the sensitivity of CPT I to malonyl-CoA inhibition after 3 h or 6 h re-feeding. After 24 h re-feeding, both the affinity of the enzyme for palmitoyl-CoA and the activity of the enzyme were still not significantly different from those for the enzyme in mitochondria from 24 h-starved animals. By contrast, the sensitivity of CPT I to malonyl-CoA inhibition was largely, but not fully, restored to that observed in mitochondria from fed rats.