SUPPLEMENTAL DIETARY COPPER AND THE DESATURATION OF 1-14C-STEAROYL-COENZYME A BY PORCINE HEPATIC AND ADIPOSE MICROSOMES

Abstract

Optimal assay conditions for porcine hepatic and adipose stearoyl-CoA desaturase systems were established. In each of the two experiments conducted, pigs were allotted to four groups in a 2 × 2 factorial design involving two diets (basal or basal plus 250 ppm supplemental copper) and two sexes (barrows and gilts). In experiment 1 (16 pigs), copper supplementation of the swine diet resulted in a slight but nonsignificant increase in the ability of hepatic microsomes to desaturate 1-14C-stearoyl-CoA. With an increased number of animals (24 pigs) in experiment 2, significant increases in stearoyl-CoA desaturase activity were observed in the hepatic (P < 0.05) and adipose (P < 0.01) microsomes of copper-supplemented pigs. No sex differences nor copper × sex interactions in the activities of the stearoyl-CoA desaturase systems were found. It is suggested that supplemental dietary copper enhances the specific activities of both hepatic and adipose stearoyl-CoA desaturase systems, and that this enhancement contributes to the observed decrease in stearate and increase in oleate content of depot fat.