Comparative changes in the lipogenic enzyme activities and in the in vivo fatty acid synthesis in liver and adipose tissues during the post-weaning growth of male rats.

Changes in the specific activities of acetyl-CoA-carboxylase (ACX), malic enzyme (ME) and glucose-6-phosphate dehydrogenase (G-6-PD) were compared to changes in de novo lipogenesis measured by in vivo incorporation of [3H] of tritiated water into fatty acids of liver and of perirenal and dorsal subcutaneous adipose tissues. In the adipose tissues, the specific activities of the three enzymes rather closely followed fluctuations in the rate of fatty acid synthesis. In the liver, ACX and especially ME activities were satisfactory indicators of de novo lipogenesis; G-6-PD activity did not depend on de novo lipogenesis.