Omayma Alshaarawy1, Emily Kurjan2, Nguyen Truong2, L Karl Olson2. 1. Department of Family Medicine, Michigan State University, East Lansing, Michigan, USA. 2. Department of Physiology, Michigan State University, East Lansing, Michigan, USA.
Abstract
OBJECTIVE: Evidence suggests that cannabinoid-1 receptor (CB1R) activation is associated with increased food intake and body weight gain. Human epidemiological studies, however, show decreased prevalence of obesity in cannabis users. Given the overlapping and complementary functions of the cannabinoid receptors (CB1R and CB2R), mice lacking CB2R and mice lacking both CB1R and CB2R were studied. METHODS: A high-fat diet was used to study metabolic changes in male mice lacking CB2R (CB2-/- ) or lacking both CB1R and CB2R (double-knockout [CB-DKO]) compared with wild-type mice. RESULTS: When CB2-/- mice were maintained on a high-fat diet, their weight gain was not different from wild-type mice (gaining 19 and 21 g, respectively), whereas CB-DKO mice gained only 5 g. There were no significant differences in food intake or locomotor activity between the three groups. Respiratory exchange rate and heat production were elevated in CB-DKO mice, with upregulation of adipose tissue thermogenic genes. Glucose tolerance test and insulin levels indicated increased insulin sensitivity in CB-DKO mice, whereas CB2-/- displayed signs of impaired glucose clearance. CONCLUSIONS: These results indicate that lacking both CB1R and CB2R protected mice from diet-induced obesity, possibly through the prominent role of CB1R in obesity or through an interactive effect of both receptors.
OBJECTIVE: Evidence suggests that cannabinoid-1 receptor (CB1R) activation is associated with increased food intake and body weight gain. Human epidemiological studies, however, show decreased prevalence of obesity in cannabis users. Given the overlapping and complementary functions of the cannabinoid receptors (CB1R and CB2R), mice lacking CB2R and mice lacking both CB1R and CB2R were studied. METHODS: A high-fat diet was used to study metabolic changes in male mice lacking CB2R (CB2-/- ) or lacking both CB1R and CB2R (double-knockout [CB-DKO]) compared with wild-type mice. RESULTS: When CB2-/- mice were maintained on a high-fat diet, their weight gain was not different from wild-type mice (gaining 19 and 21 g, respectively), whereas CB-DKOmice gained only 5 g. There were no significant differences in food intake or locomotor activity between the three groups. Respiratory exchange rate and heat production were elevated in CB-DKOmice, with upregulation of adipose tissue thermogenic genes. Glucose tolerance test and insulin levels indicated increased insulin sensitivity in CB-DKOmice, whereas CB2-/- displayed signs of impaired glucose clearance. CONCLUSIONS: These results indicate that lacking both CB1R and CB2R protected mice from diet-induced obesity, possibly through the prominent role of CB1R in obesity or through an interactive effect of both receptors.
Authors: Vanessa Deveaux; Thomas Cadoudal; Yasukatsu Ichigotani; Fatima Teixeira-Clerc; Alexandre Louvet; Sylvie Manin; Jeanne Tran-Van Nhieu; Marie Pierre Belot; Andreas Zimmer; Patrick Even; Patrice D Cani; Claude Knauf; Remy Burcelin; Adeline Bertola; Yannick Le Marchand-Brustel; Philippe Gual; Ariane Mallat; Sophie Lotersztajn Journal: PLoS One Date: 2009-06-09 Impact factor: 3.240
Authors: Kathryn Miranda; William Becker; Philip B Busbee; Nicholas Dopkins; Osama A Abdulla; Yin Zhong; Jiajia Zhang; Mitzi Nagarkatti; Prakash S Nagarkatti Journal: iScience Date: 2022-08-24