Endogenous catecholamines during noradrenaline and adrenaline hypertension.

Intravenous infusion of noradrenaline (NA) (30 micrograms/kg) results in reflectory increase of adrenaline (A), this has been established by spectrofluorometrical assay of the difference in the plasma catecholamine level during noradrenalinemia with and without elimination of circulatory reflexes. Analogically, intravenous infusion of A brings about reflectory increase of NA level. In the presence of hexamethonium a substantial amount of injected NA remains in the blood. After adrenalectomy the uptake of injected catecholamines is greatly enhanced.