Influence of 2-deoxy-D-glucose on feeding in the rat at different times of the light-dark cycle.
Two concentrations of 2-deoxyglucose (2-DG) were injected into adult male Long-Evans rats at four times during the 12:12 light/dark cycle. At low concentrations (300 mg/kg) in the first 3 h of a 6-h test period, 2-DG significantly increased feeding (268%) in the early part of the light period (EL) when compared to uninjected and saline-treated controls. In the late light (LL), 2-DG increased feeding by 48% but this was not statistically significant. For the high-concentration groups (750 mg/kg), 2-DG increased feeding by 240% in the EL, 117% in the LL, 50% in the early dark (ED) and 45% in the late dark (LD). As there was no significant interaction, it was concluded that 2-DG facilities feeding at all times of the day. In the second 3 h of the recorded 6 h, 2-DG decreased feeding by 37-45% in the ED and middle dark (MD) when compared to controls, although the suppression was significant only for the low concentration of 2-DG. There was some support from data on water intake and latencies to eat and drink for the view that 2-DG-induced feeding was not secondary to thirst stimulated by hypertonic injection fluids. It is concluded that 2-DG injection facilitates feeding for a few hours but the net effect on food intake may be reduced in the light, and even nullified in the dark, by a subsequent reduction of intake in rats with free access to food.
D000818:Animals; D002940:Circadian Rhythm / Q000187:drug effects; D003624:Darkness; D003837:Deoxy Sugars / Q000494:pharmacology*; D003847:Deoxyglucose / Q000008:administration & dosage / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D004327:Drinking Behavior / Q000502:physiology; D005247:Feeding Behavior / Q000187:drug effects* / Q000502:physiology; D008027:Light; D008297:Male; D051381:Rats
D003837:Deoxy Sugars; D003847:Deoxyglucose