Evolution of 3-hydroxy-3-methylglutaryl-CoA reductase and microsomal membrane fluidity throughout chick embryo development.
The pattern of chick liver and brain 3-hydroxy-3-methylglutaryl-CoA reductase and its relationship with changes in microsomal membrane fluidity was studied during embryonic and postnatal development. A peak of brain activity was found at 19 days of embryonic development, while liver activity only increased after hatching. A significant increase in cholesterol content of brain microsomes occurred at about 14 days of incubation, decreasing afterwards. No significant variations were observed in liver microsomes during the same period. A similar profile was found in the phospholipid content of both brain and liver microsomes. The cholesterol/lipidic phosphorus molar ratio of brain and liver microsomes did not exhibit significant changes throughout embryonic and postnatal development. These results demonstrate that membrane-mediated control does not regulate the evolution of reductase activity during this developmental period.
D000375:Aging; D000818:Animals; D001921:Brain / Q000196:embryology* / Q000201:enzymology / Q000254:growth & development; D002642:Chick Embryo / Q000502:physiology*; D006903:Hydroxymethylglutaryl CoA Reductases / Q000378:metabolism*; D007425:Intracellular Membranes / Q000201:enzymology*; D008099:Liver / Q000196:embryology* / Q000254:growth & development; D008560:Membrane Fluidity; D008861:Microsomes / Q000201:enzymology*; D008862:Microsomes, Liver / Q000201:enzymology
D006903:Hydroxymethylglutaryl CoA Reductases