Plasma catecholamine levels and vascular response in deoxycorticosterone acetate hypertension of rats

1. In rats with deoxycorticosterone acetate (DOCA) hypertension basal plasma concentrations of noradrenaline and adrenaline correspond to those of sham-treated controls. 2. In DOCA-treated rats frusemide caused a more pronounced increase in plasma noradrenaline than in control rats. This difference was not observed for adrenaline. 3. In the isolated perfused hind-limb preparation the sensitivity to noradrenaline was already enhanced before blood pressure was elevated. 4. These results suggest that the adrenergic vascular tone is increased in DOCA hypertension in rats.