Erucic acid metabolism by rat heart preparations

Rat heart preparations metabolized erucic acid at much slower rates than palmitic acid. This applied for activation reaction, for the conversion of acyl-CoA to acylcarnitine, and for the utilization of acyl group for oxidation. As compared to palmityl-CoA, erucyl-CoA exhibited a lower affinity for carnitine palmityltransferase (EC 2.3.1.23), the respective apparent Michaelis constants were 43 and 83 muM. Presence of erucyl-CoA or erucyl-carnitine slowed the mitochondrial oxidation of palmityl groups apparently because of the slower oxidation of erucyl groups. However, presence of erucate did not inhibit the activation of palmitate. Heart mitochondria obtained from rats fed rapeseed oil (50 cal %) or corn oil diet for 3 days showed similar abilities for the coupled oxidation of various substrates and similar carnitine palmityltransferase activities. Thus, a suggestion of gross mitochondrial malfunction following rapeseed oil consumption was not confirmed.