Acidic fibroblast growth factor and keratinocyte growth factor stimulate fetal rat pulmonary epithelial growth. Deterding, Robin R., Christopher R. Jacoby, and John M. Shannon. Division of Pulmonary Medicine, Department of Pediatrics, University of Colorado, The Children's Hospital, and National Jewish Center for Immunology and Respiratory Medicine, Denver, Colorado 80218, Department of Medicine, National Jewish Center for Immunology and Respiratory Medicine, and Division of Pulmonary Sciences and Critical Care Medicine, University of Colorado Health Science Center, Denver, Colorado 80206
APStracts 3:0080L, 1996.
We have shown that pulmonary epithelial growth and differentiation can occur if pulmonary mesenchyme is replaced with a mixture of growth factors (TGM) that consists of adult rat BALF, insulin, EGF, cholera toxin, aFGF and FBS. In the present study we have defined the importance of specific components of TGM. Day 14 fetal rat distal lung epithelium, devoid of mesenchyme, was enrobed in growth-factor depleted Matrigel and cultured for 5 days in various soluble factors. We found that deleting aFGF or cholera toxin from TGM significantly reduced DNA synthesis. Epithelial proliferation was not significantly different when KGF replaced aFGF in TGM. KGF, however, required the presence of a basal medium containing cholera toxin, insulin and serum for optimal proliferation. We then added specific growth factors to the basal medium and showed that aFGF and KGF were more potent mitogens than EGF, TGF[alpha], and HGF. Additionally, basal medium + KGF also allowed progression to a distal alveolar phenotype. We conclude that aFGF and KGF may be important mediators in epithelial-mesenchymal interactions. 

Received 13 November 1995; accepted in final form 7 May 1996.
APS Manuscript Number L329-5.
Article publication pending Am. J. Physiol. (Lung Cell. Mol.
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 June 96