Differential effects of 2-deoxy-D-glucose on plasma glucose, free fatty acids and feeding during the light and dark cycle in rats.

The effects of 2-deoxy-D-glucose (2-DG) combined with 0 to 6 hr of food deprivation on plasma glucose (PG), plasma free fatty acid (PFFA) levels and feeding were compared during the 2 parts of the diurnal cycle. In one group, PG and PFFA were measured prior to the injection of either 2-DG or saline and 90 min after injections without restoration of access to food. In a second group, food was reintroduced following injection and intake was measured. At night, PG and PFFA measured prior to injections decreased and increased with respect to the length of food deprivation. Ninety minutes after 2-DG, PG and PFFA were elevated above control levels as a function of previous deprivation. During the day, fasting time did not affect PG and PFFA 90 min after a saline injection; but, after 2-DG, PG increased and PFFA decreased irrespective of the previous deprivation period. At night, food intake increased after saline and 2-DG as a function of fast duration, but increases were significantly lower after 2-DG. During the day, the duration of food deprivation did not affect food intake after 2-DG and saline; but irrespective of previous food deprivation, the cumulative intake of the first 2 hr was higher after 2-DG. Results are discussed in relation to the dual activation by 2-DG of facilitatory and inhibitory mechanisms of food intake.