Ks. Curtis et Em. Stricker, ENHANCED FLUID INTAKE BY RATS AFTER CAPSAICIN TREATMENT, American journal of physiology. Regulatory, integrative and comparative physiology, 41(2), 1997, pp. 704-709
These studies examined stimulated fluid intake by rats in which vagall
y mediated signals of gastric distension were blunted by systemic trea
tment with the neurotoxin capsaicin, as verified by the loss of cholec
ystokinin-induced inhibition of feeding. After overnight food deprivat
ion, intake of a 10% sucrose solution by capsaicin-treated rats was gr
eater than that by control rats. Similarly, capsaicin-treated rats dra
nk more water than did control rats when stimulated by plasma hyperosm
olality after intraperitoneal administration of hypertonic NaCl or by
isosmotic hypovolemia after subcutaneous administration of a hyperonco
tic 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 tho
se by control rats within 5-15 min. These results suggest that early s
ignals of gastric distension, such as those that occur during normal e
pisodes of food, water, or NaCl intake, may modulate ongoing ingestion
and that, with the attenuation of such general inhibitory signals, in
gestion continues until gastric distension becomes larger and/or later
postgastric signals are detected.