Effects of SR141716A, a central cannabinoid receptor antagonist, on food-maintained responding

previous reports have indicated that administration of the central cannabin oid receptor (CBI) antagonist SRI41716A decreases intake of highly palatabl e food and drink. Disruption of normal food intake has been reported only a t high doses known to disrupt spontaneous behaviors. The present study was designed to determine if rates of responding for normal food were sensitive to the effects of cannabinoid receptor blockade. Adult, male Sprague-DawIe y rats were trained to lever press for normal food pellets under a fixed-ra tio 15 (FR 15) schedule of reinforcement. SR141716A (0.3-3.0 mg/kg) produce d dose-dependent reductions in response rate. WIN 55,2 12-2 (0.3 mg/kg), a high efficacy cannabinoid agonist, given as a pre-treatment to SR141716A, s ignificantly attenuated the rate-suppressing effects of SR141716A, suggesti ng a principal role of CB1 receptors in mediating these behavioral effects. These data indicate that high palatability is not necessary to observe an anorectic effect of SR141716A. (C) 2000 Elsevier Science Inc. All rights re served.