Characterization Of The Distribution And Expression Of EGF, BFGF, IGF-I And TGF-β1 From Saliva And Salivary Glands

Objective. The purpose of this study was: (1) to quantitatively determine the concentration of epidermal growth factor (EGF), basic fibroblast growth factor (bFGF), transforming growth factor beat 1 (TGF-β1), and insulin-like growth factor I (IGF-I) in normal human whole saliva (WS), parotid saliva (PS), and saliva from the submandibular and sublingual glands (SMS+SLS). (2) to study the occurrence , localization and mRNA expression of bFGF and FGFR1, FGFR2, FGFR3, FGFR4 in adult rat salivary glands. Material and Methods. WS, PS and SMS+SLS were collected from eleven healthy volunteers. The EGF, bFGF, IGF-I and TGF-pl were measured with ELISA technique. Immunohistochemistry and RT-PCR methods were used to detect the immunoreactivity localization and mRNA expression of bFGF and FGFR1, FGFR2, FGFR3, FGFR4 in adult rats parotid and submandibular glands.Results. EGF in PS was 4-fold higher than that in WS and in SMS+SLS. The IGF-I in PS was almost 2-fold higher than in WS and in SMS+SLS. The concentration of bFGF in WS was similar to that in PS and in SMS+SLS. The TGF-pl was below the detection level.Immunohistorchemical localization of bFGF and FGFRS in rat salivary glands revealed specific immunostaining of the granular ductal cell of the parotid and submandibular glands. RT-PCR amplification of total RNA from the parotid and submandibular glands of rats demonstrated the presence of bFGF and FGFR1, FGFR2, FGFRS mRNA. Conclusion. Our studies show that the parotid gland seems to be the major source of EGF and IGF-I, suggesting a major importance of these glands in the growth factor balance of the oropharyngx and upper digestive tract. Salivary bFGF probably originates equally from all major salivary glands.Our studies suggest bFGF and FGFRS could be endogenous synthesis by rat salivary glands. Thus, salivary glands appear to be an exocrine source of the bFGF in rat saliva.