In vitro arterial responses to vasopressin in subjects with a family history of hypertension.
Intrinsic vascular responsiveness was examined in isolated, helically cut strips of cystic artery from 32 normotensive women. Contractions were elicited by vasopressin, norepinephrine, 5-hydroxytryptamine and transmural electrical stimulation. Of the 32 subjects, 17 had a family history of hypertension in a first-degree relative (parent, sibling, or adult offspring) and 15 had no family history of hypertension. The ages and mean arterial blood pressures of the two groups were not different: 39 +/- 12 versus 35 +/- 11 years (mean +/- SD; p = 0.263) and 87 +/- 4 versus 85 +/- 5 mm Hg (p = 0.214) respectively. The vasopressin dose-response curve was significantly shifted to the left for arteries of those subjects with a family history of hypertension compared with that for arteries of subjects with no family history (e.g., response--percent of norepinephrine maximum--to 100 mU/ml = 31 +/- 23 versus 12 +/- 16; p = 0.014). All other responses were not significantly different, although in general the arteries of those subjects with a family history tended to have greater responses to all stimuli except norepinephrine. Arteries from the two groups did not differ with respect to physical dimensions (e.g., cross-sectional area), passive mechanical properties, or maximal responses to norepinephrine. The data indicate that altered intrinsic vascular responsiveness is linked to a family history of hypertension in normotensive subjects and thus could play a role in the familial aggregation of elevated blood pressure.
- Copyright © 1985 by American Heart Association