I. c. v. dopamine fails to alter adrenomedullary function in rats

Intracerebroventricularly (i.c.v.) administered dopamine (50-400 micrograms/kg, 30 min; 400 micrograms/kg, 2 and 4 h) did not induce statistically significant changes in heart adrenaline (presumed to represent the adrenaline release from the adrenals). Only the highest dose (400 micrograms/kg, 30 min) brought about significant increase in adrenal dopamine (reflecting the catecholamine synthesis), accompanied by increase in heart dopamine, indicating leakage of dopamine into the peripheral circulation. The results did not support involvement of the central dopamine receptors in the short-term control of the adrenomedullary function in rats.