title: Absorption of epidermal growth factor occurs through the gastrointestinal tract and oral cavity in adult rats.
abstract: 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 after administration by sublingual lozenge, whereas 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 after oral administration.
authors.affiliation: Department of Oral Biology, University of Florida, Gainesville 32610, USA.
authors.forename: K R
authors.initials: KR
authors.lastname: Purushotham
authors.forename: K
authors.initials: K
authors.lastname: Offenmüller
authors.forename: A T
authors.initials: AT
authors.lastname: Bui
authors.forename: T
authors.initials: T
authors.lastname: Zelles
authors.forename: J
authors.initials: J
authors.lastname: Blazsek
authors.forename: G S
authors.initials: GS
authors.lastname: Schultz
authors.forename: M G
authors.initials: MG
authors.lastname: Humphreys-Beher
mesh_terms: D000042:Absorption; D000286:Administration, Sublingual; D000818:Animals; D004064:Digestive System / Q000378:metabolism*; D004815:Epidermal Growth Factor / Q000378:metabolism*; D066246:ErbB Receptors / Q000378:metabolism; D005260:Female; D007457:Iodine Radioisotopes; D009055:Mouth / Q000378:metabolism*; D051381:Rats; D017207:Rats, Sprague-Dawley; D014018:Tissue Distribution
chemical_list: D007457:Iodine Radioisotopes; D004815:Epidermal Growth Factor; D066246:ErbB Receptors