EFFECT OF POSITIVE FAMILY HISTORY OF HYPERTENSION ON THE BLOOD-PRESSURE AND CATECHOLAMINE RESPONSES TO A 6 HOUR ADRENALINE INFUSION

1. The effects of 6h infusions of adrenaline (INF-A) or dextrose (INF-D) and of post-infusion cold pressor test (CPT) were compared in normal subjects, with (FH+) and without (FH -) a family history of hypertension. 2. Increased urinary excretion rates suggested facilitated noradrenaline (NA) release during and after INF-A in both FH + and FH -. 3. Urinary adrenaline (UADR) excretion increased during INF-A, as expected, and was also slightly higher after INF-A than INF-D. 4. The effect of INF-A on systolic blood pressure (SBP) was greater in FH - than in FH + but diastolic blood pressure (DBP) did not fall as quickly with nocturnal recumbency after INF-A in FH +. 5. A significantly greater response in plasma NA to CPT was seen in FH + than in FH - after INF-A. A similar trend was also seen after INF-D. 6. Increases in DBP due to CPT were higher in FH + than in FH - after both infusions. 7. This study provides evidence of increased noradrenergic activity during and after INF-A, and also of a difference in response to sympathetic stimulation between FH + and FH -.