Objective: To investigate the effect of SR141716, a selective CB1 receptor antagonist, on energy expenditure and on glucose uptake in isolated soleus muscle of Lep(ob)/Lep(ob) mice.
Design: Female Lep(ob)/Lep(ob) mice (8-10 weeks old) were treated with SR141716 (10 mg/kg, i.p. once daily) or vehicle for 7 days.
Measurements: Oxygen consumption, daily food and water intake, body weight and glucose uptake in isolated soleus muscle.
Results: SR141716 (10 mg/kg, i.p. once daily) resulted in a significant reduction of daily food intake (P<0.01) and body weight (P<0.05) 5 days after daily treatment. Body weight continued to be lower for the rest of the treatment period (P<0.05). There was no significant difference in body weight between the pair-fed and vehicle-treated animals. A 7-day treatment with SR141716 (10 mg/kg, i.p. once daily) caused 37% increase in basal oxygen consumption compared to that of vehicle-treated (90 min mean; P<0.01), and a significant 68% increase in glucose uptake in isolated soleus muscle preparations.
Conclusion: It is concluded that SR141716 has a direct effect on energy expenditure suggesting that the antiobesity effect of SR141716 is due to activation of thermogenesis in addition to the initial hypophagia. The increase in soleus muscle glucose uptake with SR141716 treatment may contribute to the improved glycaemia seen in the previous studies.