[Increase of brain serotonin and its metabolite in rats caused by meclofenoxate]

Influence of meclofenoxate (MF) on the 5-HT and 5-HIAA contents in the cortex, diencephalon and brain stem of the rat was studied with the following results. MF caused a dose-dependent elevation of 5-HIAA level in the three different brain regions and particularly in the brain stem. An increase of 5-HT was also noted in the brain stem, whereas 5-HT in the diencephalon tended to decrease. The increase of 5-HT after pargyline was accelerated and the pargyline-induced decrease of 5-HIAA was equally inhibited by MF and probenecid, which suggests that MF blocks the efflux of 5-HIAA from the brain. The effects of MF on the brain 5-HT and 5-HIAA contents were identical with those of its hydrolysate, p-chlorophenoxyacetic acid.