Gut vagal afferent lesions increase meal size but do not block gastric preload-induced feeding suppression.
Subdiaphragmatic vagal afferent (SVA) signals arising from gut sites may provide critical feedback for the control of food intake within a meal. To evaluate the role of SVAs in both spontaneous and scheduled meals, food intake was assessed in two paradigms in male Sprague-Dawley rats. In the first study, control (Con) rats (n = 6) and rats with subdiaphragmatic vagal deafferentation (SDA) (n = 7) had 12-h nightly access to Ensure liquid diet (1 kcal/ml). SDA rats had larger and fewer meals and maintained initial rapid rates of licking, yet total numbers of licks were unaffected. In the second study, Con (n = 8) and SDA (n = 7) rats had scheduled access to 12. 5% liquid glucose after overnight food deprivation. Glucose intake was assessed after 5-ml gastric preloads of 0.9% saline or glucose, peptone, and Intralipid solutions at three concentrations (0.5, 1, and 2 kcal/ml). Glucose and peptone preloads suppressed intake similarly in Con and SDA rats, whereas Intralipid was ineffective. These results suggest that meal-related SVA signals 1) are not critical in determining preload-induced feeding suppression after deprivation, yet 2) contribute to satiety during spontaneous meals.
Schwartz
G J
GJ
Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, School of Medicine, Baltimore, Maryland 21205, USA. gjs@jhmi.edu
Salorio
C F
CF
Skoglund
C
C
Moran
T H
TH
D000284:Administration, Oral; D000344:Afferent Pathways / Q000503:physiopathology; D000818:Animals; D003714:Denervation; D004435:Eating / Q000187:drug effects / Q000502:physiology*; D005217:Fat Emulsions, Intravenous / Q000494:pharmacology; D005246:Feedback; D005247:Feeding Behavior / Q000187:drug effects / Q000502:physiology; D005508:Food Deprivation / Q000502:physiology; D005947:Glucose / Q000494:pharmacology; D007422:Intestines / Q000294:innervation*; D008297:Male; D010461:Peptones / Q000494:pharmacology; D051381:Rats; D017207:Rats, Sprague-Dawley; D012965:Sodium Chloride / Q000494:pharmacology; D013270:Stomach / Q000502:physiology*; D014630:Vagus Nerve / Q000503:physiopathology
D005217:Fat Emulsions, Intravenous; D010461:Peptones; D012965:Sodium Chloride; D005947:Glucose