title: Effects of calcium deprivation on n-6 fatty acid metabolism in growing rats.
abstract: Two separate experiments examining the effects of calcium deficiency on plasma and liver fatty acids in rats were conducted. In Experiment I, weanling male Sprague-Dawley rats were fed a calcium-deficient diet with or without the supplementation of 5 or 20 g/kg calcium for 22 days. There were no significant differences in plasma and liver fatty acid distribution between the two calcium-supplemented groups. However, calcium deficiency significantly elevated the levels of 18:3n-6 in plasma and liver cholesteryl esters and liver phospholipids, while it reduced the levels of 20:3n-6 in plasma cholesteryl esters. In Experiment II, weanling rats were fed a calcium-deficient diet supplemented with 5 g/kg calcium for 22 days. After overnight fast, animals were given by intragastric feeding a dose of 4 g/kg body wt gamma-linolenic acid concentrate (containing 92% 18:3n-6 ethyl ester), and were killed 22 hr later. The levels of 18:3n-6 were significantly higher, whereas the levels of 20:3n-6 were either not changed or lower than those in calcium-supplemented group. In both experiments, the ratios of (20:3n-6 + 20:4n-6)/18:3n-6 in plasma and liver lipids were significantly reduced in calcium-deficient rats. These results suggest that calcium may play an important and specific role in the process of elongation of 18:3n-6 to 20:3n-6.
authors.affiliation: Efamol Research Institute, Kentville, Nova Scotia, Canada.
authors.forename: Y S
authors.initials: YS
authors.lastname: Huang
authors.forename: K R
authors.initials: KR
authors.lastname: McAdoo
authors.forename: J
authors.initials: J
authors.lastname: Mitchell
authors.forename: D F
authors.initials: DF
authors.lastname: Horrobin
mesh_terms: D000375:Aging; D000818:Animals; D001835:Body Weight; D002118:Calcium / Q000172:deficiency* / Q000494:pharmacology; D005227:Fatty Acids / Q000378:metabolism*; D008099:Liver / Q000254:growth & development / Q000378:metabolism; D008297:Male; D051381:Rats; D011919:Rats, Inbred Strains / Q000254:growth & development*; D012016:Reference Values
chemical_list: D005227:Fatty Acids; D002118:Calcium