Enhanced fluid intake by rats after capsaicin treatment.
Curtis, Kathleen S., and Edward M. Stricker.
Department of Neuroscience, University of Pittsburgh, Pittsburgh,
PA 15260 USA
APStracts 3:0363R, 1996.
These studies examined stimulated fluid intake by rats in which
vagally-mediated signals of gastric distension were blunted by
systemic treatment with the neurotoxin capsaicin, as verified by the
loss of cholecystokinin-induced inhibition of feeding. After
overnight food deprivation, intake of a 10% sucrose solution by
capsaicin-treated rats was greater than that by control rats.
Similarly, capsaicin-treated rats drank more water than did control
rats when stimulated by plasma hyperosmolality following ip
administration of hypertonic NaCl or by isosmotic hypovolemia
following sc administration of a hyperoncotic colloidal solution.
Finally, during chronic administration of the mineralocorticoid
deoxycorticosterone acetate, capsaicin-treated rats consumed more
concentrated saline than did control rats. In all tests, intakes by
capsaicin-treated rats were significantly greater than those by
control rats within 5-15 min. These results suggest that early
signals of gastric distension, such as those that occur during normal
episodes of food, water, or NaCl intake, may modulate ongoing
ingestion, and that with the attenuation of such general inhibitory
signals ingestion continues until gastric distension becomes larger
and/or later postgastric signals are detected.
Received 7 June 1996; accepted in final form 12 September 1996.
APS Manuscript Number R322-6.
Article publication pending Am. J. Physiol. (Regulatory Integrative
Comp. Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 November 1996