Centrally administered leumorphin possesses potent depressor activity in conscious rats

The effect of intracerebroventricular (i.c.v.) administration of leumorphin on basal blood pressure and angiotensin II (AII)-stimulated increase in blood pressure was examined in conscious unrestrained rats. The i.c.v. injection of leumorphin (0.06 and 0.6 nmol) elicited significant depressor effect. The i.c.v. administration of leumorphin with AII (0.1 nmol) significantly attenuated the AII-induced pressor response and, furthermore, lowered blood pressure below the basal level. These results suggest that leumorphin is involved in the central control of blood pressure.