Handgrip Increases Endothelin-1 Secretion in Normotensive Young Male Offspring of Hypertensive Parents

Objectives. We tested the hypothesis that an abnormal response of plasma endothelin-1 (ET-1) is elicited by handgrip exercise (HG) in young normotensive offspring of hypertensive parents.Background. It has been hypothesized that ET-1 is involved in blood pressure control and plays a pathophysiologic role in the development of clinical hypertension.Methods. Two groups of healthy male subjects, 11 with hypertensive parents (group A) and 10 without a family history of hypertension (group B), underwent 4 min of HG at 50% maximal capacity. Heart rate and blood pressure and plasma levels of ET-1, epinephrine and norepinephrine were measured at baseline, peak HG, and after 2 (R2) and 10 (R10) min of recovery.Results. Group A had higher norepinephrine levels than group B throughout the test (baseline 181 ± 32 SEM] vs. 96 ± 12 pg/ml, p < 0.05; peak HG 467 ± 45 vs. 158 ± 12 pg/ml, p < 0.000001; R2 293 ± 46 vs. 134 ± 8 pg/ml, p < 0.01; R10 214 ± 27 vs. 129 ± 10 pg/ml, p < 0.0005); no significant difference in epinephrine levels was detected. Compared with group B subjects, group A had higher baseline ET-1 levels (1.07 ± 0.14 vs. 0.59 ± 0.11 pg/ml, p < 0.02), which increased to a greater extent at peak HG (1.88 ± 0.31 vs. 0.76 ± 0.09 pg/ml, p < 0.005) and R2 (2.46 ± 0.57 vs. 1.31 ± 0.23 pg/ml, p < 0.05) and remained elevated at R10 (3.16 ± 0.78 vs. 0.52 ± 0.09 pg/ml, p < 0.002). Multivariate analysis demonstrated that only a family history of hypertension (chi-square = 7.59, p = 0.0059) and ET-1 changes during HG (chi-square = 4.23, p = 0.0398) were predictive of blood pressure response to HG and that epinephrine and norepinephrine were not.Conclusions. The response to HG in offspring of hypertensive parents produced increased ET-1 plasma levels and resulted in a sustained ET-1 release into the bloodstream during recovery compared with offspring of normotensive parents. This may be an important marker for future clinical hypertension.