Effects of rhynchophylline on motor activity of mice and serotonin and dopamine in rat brain.

Rhynchophylline (Rhy) reduced the spontaneous motor activity and enhanced the sedative and hypnotic effects of sodium pentobarbital in mice. The effects of Rhy on serotonin (5-HT) and dopamine (DA) concentrations in rat brain, and the release of 5-HT and DA from the regional brain slices were studied by a fluorescence detector. Rhy increased the 5-HT content in the hypothalamus and cortex, but reduced the DA concentrations in the cortex, amygdala, and spinal cord. Rhy promoted the release of endogenous DA from 4 brain regions. The release of 5-HT was increased in 2 brain regions and decreased in hypothalamus slice. However, Rhy inhibited the release of both 5-HT and DA evoked by high potassium.