Proliferation and migration of endothelial cells is promoted by endothelins via activation of etb receptors. Morbidelli, Lucia, Claudio Orlando, Carlo A. Maggi, Fabrizio Ledda, and Marina Ziche. Department of Preclinical and Clinical Pharmacology "Mario Aiazzi Mancini" Clinical Biochemistry Unit, Department of Clinical Physiopathology, University of Florence, 50134 Florence; and Pharmacology Department A. Menarini Pharmaceuticals, 50131 Florence, Italy
APStracts 2:0101H, 1995.
The growth and migration of endothelial cells are the prerequisites for vascular remodelling. The effects of endothelin 1 and 3 (ET-1, ET-3) on the proliferation and migration of endothelial cells isolated from bovine adrenal capillaries (BACE) and human umbilical veins (HUVEC) have been investigated. Cell proliferation (measured as DNA synthesis and as total cell number) and migration were significantly increased by ET-1 and ET-3. Dose dependent proliferation was produced by ET-1 and ET-3 in both cell lines, with maximal effects at 0.1 nM concentration. ET-1 and ET-3 also stimulated BACE and HUVEC mobilization in a dose-dependent manner. The maximal responses were obtained at 10 nM concentration in both BACE and HUVEC. The full agonist for the ETB receptor, ET(16-21), was able to reproduce the effects of endothelin on proliferation and migration of both cell lines. Modification of ET(16-21) at Leu17 and Ile19 and amidation of the COOH terminal were accompanied by loss of activity. The ETB receptor antagonist IRL 1038 blocked the migration induced by ET-3 and ET(16-21), while the ETA receptor antagonist BQ 123 was not effective. We conclude that endothelins, by favouring endothelial cell growth and mobilization, can contribute to neovascularization through an autocrine mechanism which requires ETB receptor activation.

Received 4 November 1994; accepted in final form 14 March 1995.
APS Manuscript Number H987-4.
Article publication pending Am. J. Physiol. (Heart Circ. Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on  4 April 1995.