AJP - Regulatory, Integrative and Comparative Physiology, Vol 248, Issue 6 686-R697, Copyright © 1985 by American Physiological Society
Abdominal vagus and regulation of ingestive behavior and body weight in golden hamsters
M. O. Miceli
A series of experiments was undertaken to examine the role of the vagus
nerve in body weight regulation and the control of ingestive behavior in
Syrian hamsters. Body weight, food and water intake, and feeding
responsiveness to the putative satiety hormone cholecystokinin (CCK) were
studied in hamsters with total subdiaphragmatic or selective gastric
vagotomy. Body weight and food intake during ad libitum feeding were
unaffected by either type of vagotomy. However, hamsters with total
subdiaphragmatic or gastric vagotomy could better maintain body weight
during intermittent food access. Vagotomy blocked feeding suppression after
low-dose (4.0 micrograms/kg) systemic injections of CCK octapeptide
(CCK-8). This blocking effect was specific to feeding suppression in
response to CCK-8, because vagotomized hamsters remained responsive to
other putative satiety hormones (bombesin, calcitonin, and
thyrotropin-releasing hormone). Hamsters with either type of vagotomy were,
however, responsive to high doses (greater than or equal to 8.0
micrograms/kg) of CCK-8, thus indicating that extravagal (possibly central
nervous system) sites of CCK action may also be relevant to the control of
feeding. The results are discussed in relation to normal vagal function in
hamsters and vagal control of ingestive behavior in other species.
