Age-related variations in acyl-CoA:retinol acyltransferase activity and vitamin A concentration in the liver and epidermis of hairless mice.
Since the factors regulating retinol esterification by acyl-CoA:retinol acyltransferase are poorly understood, we studied the age-related variations in acyl-CoA:retinol acyltransferase activity in hairless mice. Epidermis and liver were collected at intervals from birth to adolescence (0-6 weeks). Vitamin A was analyzed by high-performance liquid chromatography and acyl-CoA:retinol acyltransferase by an in vitro radioincubation assay of microsomes. Epidermal vitamin A (retinol plus retinyl esters) increased 8-10 times after birth and by the age of 3 weeks adult values were attained. This increase was accompanied by a 2-fold increase in acyl-CoA:retinol acyltransferase activity in the epidermis between 3 days and 6 weeks of age. In young animals the dependence of acyl-CoA:retinol acyltransferase on exogenous co-substrate (palmitoyl-CoA) was also lower than in adult animals. Although a pronounced age-related accumulation of retinol was recorded in the liver, the activity of acyl-CoA:retinol acyltransferase did not increase with age and there was no change in the dependence of acyl-CoA:retinol acyltransferase on exogenous palmitoyl-CoA.
D000217:Acyltransferases / Q000378:metabolism*; D000375:Aging / Q000378:metabolism*; D000818:Animals; D004817:Epidermis / Q000187:drug effects / Q000378:metabolism*; D008099:Liver / Q000187:drug effects / Q000378:metabolism*; D051379:Mice; D008812:Mice, Hairless; D008861:Microsomes / Q000201:enzymology; D008862:Microsomes, Liver / Q000201:enzymology; D010171:Palmitoyl Coenzyme A / Q000494:pharmacology; D051142:Retinol O-Fatty-Acyltransferase; D014801:Vitamin A / Q000378:metabolism*
D014801:Vitamin A; D010171:Palmitoyl Coenzyme A; D000217:Acyltransferases; D051142:Retinol O-Fatty-Acyltransferase