The pressure response of isolated perfused mesenteric arteries to norepinephrine, lysine-vasopressin and angiotensin II was evaluated after feeding 3 different sodium diets and administration of deoxycorticosterone to the intact rats. Varying sodium diet did not consistently alter vascular responsiveness to the 3 pressor agonists. In contrast, the administration of deoxycorticosterone enhanced the responsiveness to lysine-vasopressin and particularly to angiotensin II. This enhanced responsiveness was equally present following a low or a high sodium diet. These results suggest that sodium intake of the intact animal has no consistent influence on the responsiveness of isolated mesenteric rat arteries, whereas deoxycorticosterone tends to enhance the vascular response independently of sodium.