Transforming growth factor-alpha in human submandibular gland and saliva.

A sensitive sandwich enzyme immunoassay (EIA) for transforming growth factor-alpha (TGF-alpha) utilizing a polyclonal antibody that recognizes limited epitopes of both human TGF-alpha and rat TGF-alpha in combination with a monoclonal anti-TGF-alpha IgG1 galactosidase conjugate was developed. This assay shows no cross-reactivity with human epidermal growth factor. We can quantify the TGF-alpha level in not only human TGF-alpha (detection limit: 1 pg/ml), but also rat TGF-alpha (detection limit: 10 pg/ml) by virtue of cross-reactivity. Employing this assay system, we demonstrated that TGF-alpha is present in both human submandibular glands and submandibular/sublingual saliva.