Table 1. Effects of adrenoceptor blockade on body weight loss during morphine withdrawal.

Treatment	Mean (g) ± S.E.M.
pla+sal	0.2±1.3
pla+nx	2.6±0.3
mor+sal	2.6±0.3
mor+nx	14.5±1.2*** +++
pla+veh+nx	3.0±1.3
pla+praz+nx	1.4±0.3
mor+veh+nx	15.8±1.1
mor+praz+nx	11.1±0.9##
pla+veh+nx	2.4±1.0
pla+prop+nx	4.7±0.7
mor+veh+nx	15.8±1.5
mor+prop+nx	13.2±1.6

Rats were treated with pellets of placebo (pla) or morphine (mor) to induce depencence and withdrawal precipitated by naloxone (nx). Other groups of rats received vehicle (veh), prazosin (praz) or propranolol (prop). The weight loss was checked immediately before and 60 min after saline (sal) and naloxone injection. Data show the means ± SEM.

***p<0.001 vs. pla+nx;

⁺⁺⁺p<0.001 vs. mor+sal;

^##p<0.01 vs. mor+veh+nx.