Figure 7.

Morphine-stimulated GTPγS binding is changed after a single morphine exposure. Rats received morphine (20 mg/kg, s.c.) or saline, and sacrificed 24, 72, or 120 hours later for morphine-stimulated GTPγS binding assay(10 μM of morphine or vehicle in incubation buffer). Data are expressed as mean ± SEM obtained from at least 3 rats. ANOVA, *p < 0.05, **P < 0.01, compared to respective control. (-): no morphine; (+): morphine.