Pressor factors and cardiovascular pressor responsiveness in borderline hypertension. Hypertension

SUMMARY The role of various pressor factors and cardiovascular responsiveness to norepinephrine or angiotensin II in the pathogenesis of borderline hypertension was evaluated. Exchangeable body sodium, blood volume, plasma renin activity, norepinephrine or dopamine levels, and norepinephrine or epinephrine excretion rates were similar between 24 patients with borderline hypertension (mean age 34 ± 4 (SEM) years and 22 nor-mal subjects matched for age; the patients had a slight increase in supine plasma epinephrine. Pressor doses of norepinephrine or angiotensin II were significantly lower (p < 0.01 and 0.001, respectively) in the borderline hypertensive group. These findings suggest that borderline hypertension may be maintained by inappropriately increased cardiovascular response to norepinephrine and angiotensin II in the presence of normal sympathetic and renin activity and a normal body sodium-volume state.(Hypertension 3: 367-372, 1981) KEY WORDS • borderline hypertension • pressor response • norepinephrine angiotensin II • plasma catecholamines • renin • body sodium-volume state BORDERLINE hypertension signifies the grayzone between normal blood pressure (BP)and established hypertension. At least 10 % of the general adult population may have borderline hypertension.1 However, since this mixed group in-cludes persons with a normal circulation, those wit