Lr. Mcmahon et al., CONDITIONED TASTE-AVERSION IN RATS INDUCED BY THE ALPHA(1)-ADRENOCEPTOR AGONIST CIRAZOLINE, Pharmacology, biochemistry and behavior, 48(3), 1994, pp. 601-604
Recent studies have indicated that alpha(1)-adrenoceptor agonists such
as phenylpropanolamine (PPA), cirazoline, amidephrine, and SK&F-89748
suppress food intake in rats. These compounds activate alpha(1)-adren
oceptors within the paraventricular hypothalamic nucleus (PVN) and may
excite efferent fibers that inhibit feeding. Studies of the effects o
f alpha(1),-agonists suggest a specificity for feeding behavior, but n
o study to date has evaluated whether these agonists may suppress feed
ing behavior by the induction of malaise. Accordingly, the present exp
eriment examined the ability of systemically administered cirazoline (
0.1, 0.2, and 0.4 mg/kg, IP) to induce conditioned taste aversion (CTA
) to a saccharin solution. Significant CTA was noted for 0.2 and 0.4 m
g/kg cirazoline but not for 0.1 mg/kg cirazoline, compared to a vehicl
e treatment. The ED,, for cirazoline-induced aversion was computed to
be 0.3 mg/kg, which contrasts with an ED, value of 0.09 mg/kg for the
effect of cirazoline on food intake (computed in other studies). More
importantly, a 0.1 mg/kg dose of cirazoline, which is slightly greater
than that of the ED(50) value for suppression of feeding, did not ind
uce significant CTA in the present study. These results suggest that m
alaise is not a prominent factor in the suppressive activity of cirazo
line on food intake and advocate the use of cirazoline as an effective
appetite suppressant.