Antihypertensive effects of fluoxetine and L-5-hydroxytryptophan in rats.

The combination of fluoxetine (10 mg/kg) and L-5-hydroxytryptophan (5-HTP) (10 mg/kg) significantly lowered blood pressure in spontaneously hypertensive rats and in rats made hypertensive by treatment with deoxycorticosterone (DOCA) and saline. Fluoxetine alone also had a significant effect on blood pressure in DOCA hypertensive rats, but not as great an effect as the combination. Since fluoxetine is an inhibitor of serotonin reuptake and 5-HTP is the serotonin precursor, the antihypertensive effect of this drug combination strengthens previous evidence that serotonin neurons have a role in the central regulation of blood pressure.