Long-term effects of starvation-refeeding in the rat

The effects of one vs. two episodes of starvation-refeeding were studied in young male rats as a function of elapsed time between the two episodes of starvation-refeeding. Starved-refed rats ate more and gained weight faster than ad libitum-fed rats. The difference in weight gains could be attributed to the greater amount of body fat in the starved-refed rats. The responses of four NADP-linked liver dehydrogenases:isocitrate dehydrogenase (ICD)/LS-isocitrate:NADP oxidoreductase (decarboxylating) (EC 1.1.1.42), glucose-6-phosphate dehydrogenase (G6PD)/D-glucose-6-phosphate:NADP oxidoreductase (EC 1.1.1.49); 6-phosphogluconate dehydrogenase (6PGD/6-phospho-D-gluconate:NADP oxidoreductase (decarboxylating) (EC 1.1.1.44); and malic enzyme (ME)/L-malate:NADP oxidoreductase (decarboxylating) (EC 1.1.1.40) were studied. Starvation-refeeding caused an overshoot of G6PD, 6PGD, and ME, but not of ICD. A second episode of starvation caused an even greater enzyme overshoot; this difference persisted for 3 weeks with G6PD and for 2 weeks with 6PGD and ME. No significant differences in blood cholesterol were detected.