IDENTIFICATION OF ELASTIN PEPTIDES WITH VASORELAXANT ACTIVITY ON RAT THORACIC AORTA

Elastin peptides obtained in vivo from the enzymatic degradation of el astic fibers are present in the circulating human blood. In order to v erify the role that these peptides may have in the regulation of the v ascular tone, the activity of several peptides identified in the elast olytic digest of human elastin and some of their structural homologues has been tested, Three of these peptides show a vasorelaxant activity in isolated rat aorta precontracted by phenylephrine. The activity ob served is higher in the absence of the endothelium; in these condition s the IC50 for the peptides Val-Gly-Val-Ala-Pro-Gly, Val-Gly-Val-Pro-G ly and Val-Gly-Val-Hyp-Gly was 40+/-2, 73+/-2 and 10+/-1 ng/ml, respec tively. They are active in the range of the pathological circulating c oncentration and their role could be important in the regulation of va scular tone during several elastin degradative diseases. (C) 1998 Else vier Science Ltd. All rights reserved.