Hepatic branch vagotomy enhances glucoprivic feeding in food-deprived old rats.
Glucoprivic feeding induced by intraperitoneal (IP) injection of 2-deoxy-D-glucose (2-DG, 250 mg/kg body weight) in the middle of the light phase was investigated in old (age: 15-16 months) and young (age; 2.5-3.5 months) hepatic branch-vagotomized (HBV) and sham-vagotomized (SV) rats. Rats were fed either a carbohydrate-rich diet or a fat-enriched diet with a moderate carbohydrate content. The glucoprivic feeding response was greater in 13-h food-deprived old HBV rats than in 13-h food-deprived old SV rats on both diets. 2-Deoxy-D-glucose produced a greater feeding response when rats were fed the fat-enriched diet. Independent of the diet, the transient hyperphagia induced by 2-DG was followed by a long-term hypophagia in old SV rats, but not in old HBV rats. In 13-h food-deprived young rats, hepatic branch vagotomy did not affect the changes in food intake induced by 2-DG. In undeprived old and young rats, the feeding response to 2-DG, exceeding that of deprived rats, was also not affected by HBV. It is concluded that under certain conditions hepatic branch vagotomy eliminates a 2-DG-induced signal inhibiting food intake and thus enhances glucoprivic feeding. The feeding response to 2-DG therefore seems to depend on stimuli affecting food intake in an antagonistic manner.
Scharrer
E
E
Institute of Veterinary Physiology, University of Zürich, Switzerland.
Del Prete
E
E
Giger
R
R
D000344:Afferent Pathways / Q000502:physiology; D000367:Age Factors; D000818:Animals; D001786:Blood Glucose / Q000378:metabolism*; D002940:Circadian Rhythm / Q000502:physiology; D003847:Deoxyglucose / Q000494:pharmacology; D004040:Dietary Carbohydrates / Q000008:administration & dosage; D004041:Dietary Fats / Q000008:administration & dosage; D004435:Eating / Q000502:physiology*; D005508:Food Deprivation / Q000502:physiology; D006815:Hunger / Q000502:physiology*; D008099:Liver / Q000294:innervation*; D008297:Male; D051381:Rats; D013564:Sympathetic Nervous System / Q000502:physiology; D014630:Vagus Nerve / Q000502:physiology*
D001786:Blood Glucose; D004040:Dietary Carbohydrates; D004041:Dietary Fats; D003847:Deoxyglucose