[Stimulating action of hematoporphyrin on motor coordination and resistance to fatigue in rats].

The pharmacological activity of hematoporphyrin has been studied on two experimental models which are able to monitor the motor coordination in the rat, namely the natatory exhaustion and the Rota-Rod tests. A dose related effect of hematoporphyrin in increasing resistane to motor fatigue has been observed in the Rota-Rod between 2-8 mg/kg i.p. Higher doses of hematoporphyrin seem to be less effective (difasic effect). In both tests hematoporphyrin was able to potentiate the stimulating effect of d-amphetamine (6 mg/kg s.c.). The potentiation appeared to be dose related between 2 and 8 mg/kg in the Rota Rod and between 2 and 16 mg/kg in the natatory test.