Plasma endothelin 1/2 levels in healthy blood donors and in hypertensive patients: clinical application.

Normal endothelin 1/2 levels and their correlation with age were evaluated and compared with endothelin 1/2 levels in hypertensive patients. Plasma endothelin 1/2 (ET) levels were measured in healthy blood donors, mostly males, of mean age 36 +/- 8 years (36 subjects), subdivided into three groups: 17-30, 31-40 and above 40 years of age (41-59 yrs). Hypertensive patients (15 subjects) were subdivided into two groups: essential and nephrogenic hypertension. The normal ET levels in the three age groups (means +/- S.D.) were: 0.58 +/- 0.19, 0.62 +/- 0.31, and 0.80 +/- 0.28 fmol/ml, respectively. The average ET level for the whole normal population was 0.66 +/- 0.28 fmol/ml. Only the differences between the mean ET levels in the first and last group were significant (P < 0.05). The difference between the mean ET levels in smokers 0.71 +/- 0.28 fmol/ml (53% of total population) and non-smokers 0.65 +/- 0.28 fmol/ml, women and men, irrespective of age, was not found to be significant. The average ET level in all patients with hypertension (0.91 +/- 0.37 fmol/ml) was significantly higher than the average ET level in blood donors of the same age group (P < 0.05). Although patients with essential hypertension had elevated ET levels compared with control, the difference between the mean ET level in these patients (0.77 +/- 0.24 fmol/ml) and in the corresponsding control group (0.62 +/- 0.31 fmol/ml) was not significant.(ABSTRACT TRUNCATED AT 250 WORDS)