Metabolism of glycerol ether-containing lipids in dogfish (Squalus acanthias)

Abstract

Dogfish (Squalus acanthias) received intrahepatic injections of either palmitic acid-1-14C or chimyl alcohol-1-14C. The lipids of the liver were then analyzed for incorporated radioactivity. The experiments with labeled palmitic acid demonstrated that fatty acids are reductively incorporated into the alkyl and alkenyl ether chains of glycerolipids. Significantly lower specific activities were found for the diacyl alk-1′-enyl ethers and diacyl glycerol ethers than for other glycerol ether-containing lipids. These compounds may therefore represent terminal points in ether-lipid metabolism. The studies with labeled chimyl alcohol indicate that dogfish liver contains enzymes that have a high capacity for oxidatively cleaving alkyl ether linkages. Furthermore, it is probable that alkyl ethers are converted directly to alkenyl ethers, possibly via a biodehydrogenation reaction.