Response of lipogenic enzymes and plasma lipids to starvation and refeeding in the adult Japanese quail (Coturnix coturnix japonica).

I . Adult male Japanese quail (Coturnix coturnixjuponicu) were starved for 48 or 60 h and then refed for either 24 or 48 h. Weight and lipid content of carcass and livers were determined, as was the lipid content of plasma. In addition, the activities of acetyl-CoA carboxylase (EC 6 . 4 . I . 2 ; CBX), fatty acid synthetase (FAS), ATP citrate lyase (EC 4 . I . 3 .8 ; CCE) and malate dehydrogenase (decarboxylating) (NADP) (EC I . I . I .40; ME) were assayed in liver and in abdominal and neck adipose tissues (AAT and NAT, respectively) . 2. Body-weight and carcass lipids failed to return to normal in quail that had been starved for 48 h and refed during 24 h. When starving lasted 60 h, carcass lipids almost resumed the normal level only after 48 h of refeeding. All refeeding treatments caused a ~-3-fold increase in liver weight, with a parallel rise in fat content. 3. In the livers of the refed quail the specific activities of all enzymes, except CBX, reached or slightly exceeded pre-starvation levels. Because of liver enlargement, the total activities of the lipogenic enzymes in the starved-refed quail exceeded pre-starvation levels, In the normally-fed quail the contribution of AAT and NAT to total lipogenesis was insignificant, and in the starved-refed birds it still remained very small compared to that of liver, despite the pronounced relative increases of lipogenic enzyme activities in these adipose tissues.