AJP - Endocrinology and Metabolism, Vol 247, Issue 6 815-E821, Copyright © 1984 by American Physiological Society
A role for vagus nerve in regulation of protein and carbohydrate intake
E. T. Li and G. H. Anderson
The effects of vagotomy on long-term protein and carbohydrate selection or
on short-term food selection following cholecystokinin octapeptide (CCK-8)
injections, protein, or carbohydrate premeals and on brain
5-hydroxytryptamine (5HT) and catecholamine metabolism were examined in
adult rats. Vagotomy was followed by a reduction in daily protein intake
that by 3 wk had fallen to 50% of preoperative levels. A corresponding
increase in carbohydrate intake occurred so that total food intake was
maintained at approximately 93% of that consumed by the sham-operated
controls. These changes in day-to-day macronutrient selection from a choice
of high- and low-protein diets were associated with a vagotomy-induced
decreased turnover of 5HT in the hypothalamus. In meal consumption studies
vagotomy prevented a further reduction in meal size by CCK-8 but did not
block decreased consumption of total food or of protein preference of the
rats in meals taken subsequent to a protein meal. It was concluded that the
vagus nerve plays a role in regulating long-term protein and carbohydrate
preferences but not in the relationships among meal-to-meal composition and
intake.
