Absorption of epidermal growth factor occurs through the gastrointestinal tract and oral cavity in adult rats. Purushotham, Karnam R., Katelin Offenm[umlaut]uller, Anthony T. Bui, Tivadar Zelles, Jozsef Blazsek, Gregory S. Schultz, and Michael G. Humphreys-Beher. Department of Oral Biology, P.O. Box 100424, University of Florida, Gainesville, FL 32610 USA, Department of Oral Biology, Semmelweis University Medical School, 1089 Budapest VIII, Nagyvarad ter 4, HUNGARY, Department of Obstetrics and Gynecology, P.O. Box 100294, University of Florida, Gainesville FL 32610 USA
APStracts 2:0135G, 1995.
Introduction of radiolabeled epidermal growth factor ([125I]-EGF) by gavage or sublingual confinement resulted in a time dependent uptake and systemic organ dissemination in the adult rat. Intact EGF was recovered primarily from the tongue, parotid and sublingual/submandibular glands following administration by sublingual lozenge while gastrointestinal administration resulted in [125I]-EGF recovery primarily from plasma, stomach, and lung. Recovered radiolabeled EGF retained the ability to bind to the EGF -receptor. Sialoadenectomy caused an increase in [125I]-EGF in most tissues by both routes of administration. Thus, in the adult rat, at least two pathways exist for the uptake and distribution for salivary gland derived EGF present in saliva. With further analyses, sublingual absorbance of EGF may therefore provide a potential delivery route for therapeutic use of growth factor which avoids the hepatic destruction of EGF following oral administration.

Received 19 April 1995; accepted in final form 16 June 1995.
APS Manuscript Number G165-5.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 18 July 1995.