Ethanol increases the sensitivity of carnitine palmitoyltransferase I to inhibition by malonyl-CoA in short-term hepatocyte incubations

The sensitivity of carnitine palmitoyltransferase I to inhibition by malonyl-CoA was increased in mitochondria isolated from rat hepatocytes incubated with ethanol. This effect was mimicked by incubation of hepatocytes with acetaldehyde or by preincubation of isolated mitochondria with malonyl-CoA. Both ethanol and acetaldehyde increased the intracellular concentration of malonyl-CoA. Results suggest that the ethanol-induced elevation of intracellular malonyl-CoA levels may be responsible for the enhanced sensitivity of carnitine palmitoyltransferase I to inhibition by malonyl-CoA.