Absorption of epidermal growth factor occurs through the gastrointestinal tract and oral cavity in adult rats.
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.
Purushotham
K R
KR
Department of Oral Biology, University of Florida, Gainesville 32610, USA.
Offenmüller
K
K
Bui
A T
AT
Zelles
T
T
Blazsek
J
J
Schultz
G S
GS
Humphreys-Beher
M G
MG
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
D007457:Iodine Radioisotopes; D004815:Epidermal Growth Factor; D066246:ErbB Receptors