Inhibition by ginseng total saponin of the development of morphine reverse tolerance and dopamine receptor supersensitivity in mice.

1. Ginseng total saponin (GTS), 200 mg/kg i.p. 3 hr prior to morphine, inhibited the development of reverse tolerance to the ambulatory-accelerating effect of morphine. 2. GTS, 200 mg/kg, also prevented the development of dopamine receptor supersensitivity induced by the chronic administration of morphine, 10 mg/kg a day for 7 days. 3. These results suggest that GTS may be useful for the prevention and therapy of the adverse action of morphine.