CIRCULATING ENDOTHELIN IMMUNOREACTIVITY IN THE ELDERLY

To investigate plasma endothelin behaviour in aging we measured circul ating endothelin immunoreactivity in fifteen normal young adults (mean age 25.3 +/- 2.2) and nineteen elderly, apparently healthy people (me an age 85.4 +/- 3.7). The mean (+/- SD) plasma endothelin concentratio ns was 2.04 +/- 0.53 pg/ml in the young subjects and 2.6 +/- 0.56 pg/m l in the elderly subjects. The difference was statistically significan t (p<0.01). The mechanism of the increased plasma endothelin concentra tions in the elderly might be multifactorial. In particular the increa se of circulating endothelin may reflect a rise in its vascular produc tion in response to endothelial cell injury, due to a clinically silen t atherosclerotic process. It therefore has to be established if the i ncrease of circulating endothelin in elderly, apparently healthy peopl e is due only to a physiological aging or also other factors, such as un atherosclerotic process already underway but clinically silent, are involved.