Prenyltransferase and squalene synthetase in livers of neonate rats

Abstract

The liver of the newly born rat has approximately the same capacity for cholesterol biosynthesis as that of the adult animal. However, during nursing, the ability to synthesize cholesterol diminishes markedly during the early neonate period and by the end of the second week has essentially vanished. The level of the regulatory enzyme of cholesterol biosynthesis, 3-hydroxy-3-methylglutaryl-CoA reductase, closely follows this pattern (Hahn, P. and Walker, B. (1979) Can. J. Biochem. 57, 1216-1219). In contrast, we have found that two other enzymes of cholesterol biosynthesis, prenyltransferase and squalene synthetase, undergo changes in activity that provide three maxima - one on birth, one during midnursing, and one on weaning. Possible explanations for this pattern are presented.