Reversal by L-threo-3,4-dihydroxyphenylserine (L-threo-DOPS), a L-norepinephrine precursor of reserpine- or tetrabenazine-induced hypothermia.

The effects of L-threo-DOPS on the hypothermia and the decrease of brain norepinephrine (NE) concentration in the mouse pretreated with reserpine or tetrabenazine were studied. Reserpine (5 mg/kg, i.p.) or tetrabenazine (40 mg/kg, i.p.) produced a significant decrease in body temperature. The i.p. injection of L-threo-DOPS (100, 200 and 400 mg/kg) reversed these hypothermia in a dose-dependent manner. These hypothermia were also antagonized by the i.c. injection of NE (5 micrograms/mouse). Both reserpine and tetrabenazine markedly decreased the brain content of NE, and L-threo-DOPS (400 mg/kg, i.p.) recovered it. These results suggested that L-threo-DOPS would reverse the reserpine- or tetrabenazine-induced hypothermia at least in part by the formation of NE in the central nervous system.