Regulation of the oxidative NADP-enzyme tissue levels in Drosophila melanogaster. I. Modulation by dietary carbohydrate and lipid.

Wild-type third instar larvae of Drosophilia melanogaster fed a casein-sucrose synthetic diet supplemented with phosphatidylcholine (4 mg/ml) possessed 33% more tissue lipid and a modified fatty acid profile compared to larvae fed a fat free-sucrose diet. The rates of lipid synthesis and pentose shunt activity were 2.1 and 2.2 times greater respectively in larvae fed the fat free-sucrose diet than in fat-sucrose fed animals. The tissue concentrations of acetyl-CoA and acyl-CoA were 80 and 61% higher respectively, CoA 49% lower, and the NADPH/NADP+ ratio greater in fat-sucrose fed larvae than in larvae fed a fat free-sucrose diet. Thus, larvae effectively utilized dietary lipid for lipid synthesis and as a supplementary energy source to carbohydrate.