Abstract
Prostacyclin (PGI2) is produced in the vessel wall and acts as a vasodilator hormone. Measurement of plasma 6-keto-PGF1α is considered to be an index of PGI2 production. In the present study the effects of aging on the plasma 6-keto-PGF1α levels were studied in 64 normotensive and 48 essential hypertensive males. The subjects were divided into 3 groups, i.e., young (24-39 years), middle-aged (40-55 years) and elderly (over 56 years) groups. Plasma 6-keto-PGF1α was measured by specific radioimmunoassay after silicic acid column chromatographic purification. The 6-keto-PGF1α levels were lower in elderly normotensive males (10.3 ± 1.4 pg/ml, mean ± SE, n=12) than in normotensive young males (15.3± 2.3 n=30, p < 0.05). The plasma 6-keto-PGF1α levels in hypertensive elderly males (10.6 ± 1.3 pg/ml, n=10) is lower than in hypertensive young males (19.8 ± 2.2, n=17, p<0.01). These results indicate that the plasma 6-keto-PGF1α levels decreased with age in both normotensive and hypertensive groups. Thus, PGI2 production may decrease with age.
