title: Effects of dietary alpha- and gamma-linolenic acid on lipid metabolism in young and adult rats.
abstract: The effect of age on lipid metabolism was studied in rats fed diets containing safflower oil (SFO, 78% linoleic acid), evening primrose oil (EPO, 9.4% gamma-linolenic acid and 70% linoleic acid) or the mixture of safflower and linseed oil (SLO, 10.2% alpha-linolenic acid and 68% linoleic acid). The activity of hepatic HMG-CoA reductase declined with age in all groups. In adult rats, the reductase activity was high in the EPO group and low in the SLO group. The activity of hepatic cholesterol 7 alpha-hydroxylase was independent of the diet or age. Hepatic delta 6-desaturase activity was low in adult rats fed EPO. In liver microsomal phospholipids, the percentage of 22:5 n-6 decreased while that of 22:6 n-3 increased with age. The ratio of linoleate metabolites to linoleate was high in the EPO group and low in the SLO group. Liver and serum cholesterol increased with age only in rats fed the SLO diet. Thus, the results indicated an enhanced susceptibility to dietary fats with age.
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D002784:Cholesterol / Q000097:blood / Q000378:metabolism; D002790:Cholesterol 7-alpha-Hydroxylase / Q000378:metabolism; D004041:Dietary Fats / Q000008:administration & dosage / Q000494:pharmacology*; D044943:Fatty Acid Desaturases / Q000378:metabolism; D005228:Fatty Acids, Essential / Q000494:pharmacology; D006903:Hydroxymethylglutaryl CoA Reductases / Q000378:metabolism; D019787:Linoleic Acid; D008041:Linoleic Acids / Q000008:administration & dosage / Q000494:pharmacology; D008042:Linolenic Acids / Q000008:administration & dosage / Q000494:pharmacology*; D050602:Linoleoyl-CoA Desaturase; D008043:Linseed Oil / Q000494:pharmacology; D050356:Lipid Metabolism; D008297:Male; D008862:Microsomes, Liver / Q000378:metabolism; D031665:Oenothera biennis; D010743:Phospholipids / Q000378:metabolism; D010938:Plant Oils; D051381:Rats; D011919:Rats, Inbred Strains; D012450:Safflower Oil / Q000494:pharmacology; D017962:alpha-Linolenic Acid; D017965:gamma-Linolenic Acid
chemical_list: D004041:Dietary Fats; D005228:Fatty Acids, Essential; D008041:Linoleic Acids; D008042:Linolenic Acids; D010743:Phospholipids; D010938:Plant Oils; D017962:alpha-Linolenic Acid; C028498:evening primrose oil; D017965:gamma-Linolenic Acid; D012450:Safflower Oil; D008043:Linseed Oil; D002784:Cholesterol; D019787:Linoleic Acid; D006903:Hydroxymethylglutaryl CoA Reductases; D002790:Cholesterol 7-alpha-Hydroxylase; D044943:Fatty Acid Desaturases; D050602:Linoleoyl-CoA Desaturase