A neutral CB1 receptor antagonist reduces weight gain in rat

作者：Chambers Adam P; Vemuri V Kiran; Peng Yan; Wood JodiAnne T; Olszewska Teresa; Pittman Quentin J; Makriyannis Alexandros; Sharkey Keith A^*

来源：American Journal of Physiology - Regulatory, Integrative and Comparative Physiology, 2007, 293(6): R2185-R2193.

DOI：10.1152/ajpregu.00663.2007

• cannabinoid receptor
• food intake
• inverse agonist
• obesity
• emesis
• hypothermia

Cannabinoid (CB)(1) receptor inverse agonists inhibit food intake in animals and humans but also potentiate emesis. It is not clear whether these effects result from inverse agonist properties or from the blockade of endogenous cannabinoid signaling. Here, we examine the effect of a neutral CB1 antagonist, AM4113, on food intake, weight gain, and emesis. Neutral antagonist and binding properties were confirmed in HEK-293 cells transfected with human CB1 or CB2 receptors. AM4113 had no effect on forskolin-stimulated cAMP production at concentrations up to 630 nM. The K-i value of AM4113 (0.80 +/- 0.44 nM) in competitive binding assays with the CB1/2 agonist [H-3]CP55,940 was 100-fold more selective for CB1 over CB2 receptors. We determined that AM4113 antagonized CB1 receptors in brain by blocking hypothermia induced by CP55,940. AM4113 (0-20 mg/ kg) significantly reduced food intake and weight gain in rat. Compared with AM251, higher doses of AM4113 were needed to produce similar effects on food intake and body weight. Unlike AM251 (5 mg/kg), a highly anorectic dose of AM4113 (10 mg/ kg) did not significantly potentiate vomiting induced by the emetic morphine-6-glucoronide. We show that a centrally active neutral CB1 receptor antagonist shares the appetite suppressant and weight loss effects of inverse agonists. If these compounds display similar properties in humans, they could be developed into a new class of antiobesity agents.

• 出版日期2007-12
• 单位东北大学