(A) Body weight gain after s.c. implantation of placebo or morphine (75 mg) pellets.

<p>(B) Rats were injected with Tween 80 (Tw) or CP-154,526 (20 or 30 mg/kg, i.p., CP) 30 min before saline (Sal) or naloxone (1 mg/kg, s.c., Nx) to evaluate body weight loss. Data are the mean±SEM (n = 5–28). ###p<0.001 versus placebo; ***p<0.001 versus morphine+Tw+Sal; +++ p<0.001 versus placebo+Tw+Nx; &&&p<0.001 versus morphine+Tw+Nx.