A form of basic fibroblast growth factor is secreted into the adluminal fluid of the rat coagulating gland.

Rat coagulating gland and its secreted fluid contain a mitogenic substance that, by numerous criteria, appears to be similar to basic fibroblast growth factor (basic FGF). It is a potent competence factor in the BALB/c3T3 mouse embryo fibroblast assay, elutes from heparin-agarose at concentrations of NaCl greater than 1.0 M, and has an isoelectric point (pI) between 8 and 9. In coagulating gland fluid, its molecular weight was 20,000 +/- 5,000, as indicated by gel filtration on Sephadex G-200. Western blot analysis of purified factor from coagulating gland cytosol and fluid, respectively, revealed immunoreactive bands of 16,000 and 17,000 relative molecular weight similar to that of purified bovine basic FGF.