Effects of the imidazobenzodiazepine Ro 15-4513 on saccharin choice and acceptance, and on food intake, in the rat.
The general aim of the present series of experiments was to investigate the effects of the imidazobenzodiazepine, Ro 15-4513, on ingestional behavior in the rat. The more specific aims were to test its effects on preference for sweet taste, to determine if it acts as a benzodiazepine-receptor inverse agonist, and if it selectively reduces sweetness preference. The results indicated that Ro 15-4513 (1.0-10 mg/kg, i.p.) abolished the preference for a 0.05% sodium saccharin solution in a two-choice test. Water intake in the same test was unaffected. Second, at 10 mg/kg, it suppressed saccharin ingestion in an acceptance test; this effect was completely reversed by the selective benzodiazepine antagonist, Ro 15-1788 (20 mg/kg). Third, Ro 15-4513 (1.0-10 mg/kg) reduced palatable food consumption in non-deprived rats, an effect which was also antagonized by Ro 15-1788. The results are consistent the bidirectional modulation of ingestional responses to palatable taste stimuli as a consequence of drug actions at benzodiazepine receptors. Furthermore, they emphasize that any reduction in consummatory responses produced by Ro 15-4513 is likely to reflect inverse agonist characteristics, as distinct from any putative ethanol antagonist property.
School of Psychology, University of Birmingham, U.K.
S J
SJ
Cooper
D M
DM
Bowyer
G
G
van der Hoek
D000818:Animals; D001386:Azides / Q000494:pharmacology*; D001569:Benzodiazepines / Q000494:pharmacology*; D005247:Feeding Behavior / Q000187:drug effects*; D008297:Male; D051381:Rats; D012439:Saccharin / Q000502:physiology*; D013649:Taste / Q000187:drug effects*
D001386:Azides; D001569:Benzodiazepines; C042957:Ro 15-4513; D012439:Saccharin