Dual 24-hour feeding response to 2DG in rats: daytime increase and nighttime decrease.
Thirty-six rats were injected IP with 2DG (0, 250, or 500 mg/kg) at 7-day intervals, once at light onset (7 a.m.) and once at dark onset (7 p.m.), and postinjection food intake was monitored for 24 hours. Five hundred mg/kg 2DG caused food intake to rise above control levels during the first 6 hours of daylight, regardless of whether the injection had occurred that morning or the previous evening, whereas intake during the first 6 hours of darkness was consistently below control levels. In a second study, 24 rats were injected first at 7 a.m. (500 mg/kg 2DG or saline), and 7 days later at 7 p.m. (opposite drug), and food was withheld 12 hours until the light:dark period had changed. For 12 hours after food was returned, 2DG again decreased nighttime food intake (Injection 1) and increased daytime intake (Injection 2). 2DG's dual long-term effects cannot be accounted for either by malaise or by an initial action that later is compensated by its opposite. Rather, 2DG (500 mg/kg) appears to exert two independent, opposite alimentary effects which persist 18-24 hours and which change direction with phase changes in the light:dark cycle.
Thompson
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Department of Psychology, Wabash College, Crawfordsville, IN 47933.
Fleming
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Franken
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Hornback
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Boha
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D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D002940:Circadian Rhythm / Q000187:drug effects*; D003837:Deoxy Sugars / Q000494:pharmacology*; D003847:Deoxyglucose / Q000494:pharmacology*; D004305:Dose-Response Relationship, Drug; D005247:Feeding Behavior / Q000187:drug effects*; D005260:Female; D051381:Rats; D011919:Rats, Inbred Strains
D001786:Blood Glucose; D003837:Deoxy Sugars; D003847:Deoxyglucose