A serum-free in vitro model of renal microvessel development. Antes, Lisa M., Monica M. Villar, Sylvia Decker, Roberto F. Nicosia, and Dean A. Kujubu. Renal-Electrolyte and Hypertension Division, Department of Medicine, Philadelphia Veterans Affairs Medical Center and University of Pennsylvania School of Medicine, Philadelphia, PA 19104, Center for Oral Health Research, University of Pennsylvania School of Dental Medicine, Philadelphia, PA 19104, Department of Pathology, Allegheny University of the Health Sciences, Philadelphia, PA 19102
APStracts 5:0063F, 1998.
The differentiation and organization of the embryonic renal vasculature is a crucial event in renal development. To study this process, we developed a serum-free in vitro model of renal microvessel development. Mouse embryonic kidney explants, when embedded in type I collagen specifically, demonstrate outgrowth of microvascular structures when stimulated by the phorbol ester, TPA (10-50 ng/ml). Other polypeptide growth factors stimulated little, if any, microvessel outgrowth from the explants. Similar outgrowths were not observed when other embryonic tissue explants were used. The number of microvessels observed depended on the gestational age of the explants. We hypothesize that TPA induces the in situ differentiation of metanephric mesenchymal cells into endothelial cell precursors and that specific matrix proteins and cell-matrix interactions are necessary for the organization of these precursors into microvessels. Our model will allow us to examine in detail the responsiveness of metanephric kidney cells to both growth factors and extracellular matrix molecules and to understand how they influence renal endothelial cell differentiation.

Received 14 February 1997; accepted in final form 26 February
1998.
APS Manuscript Number F56-7.
Article publication pending Am. J. Physiol. (Renal Physiology).
ISSN 1080-4757 Copyright 1998 The American Physiological Society.
Published in APStracts on 9 March 1998