A potent new mesodermal growth factor from mouse submaxillary gland. A quantitative, comparative study with previously described submaxillary gland growth factors.

A new growth factor with potent growth stimulating effects on connective tissue cells of the cornea has been isolated and partially purified from mouse submaxillary glands. A computerized image analysis system has been used to quantitate the growth responses of connective tissue fibroblasts to this new growth factor and to compare its activity with that of four previously described growth factors [nerve growth factor (NGF), epidermal growth factor (EGF), mesodermal growth factor (MGF), and thymocyte-transforming factor (TTF)] also obtained from mouse submaxillary glands. The new factor is as potent a growth stimulator as the previously described MGF. All five of the growth factors possessed esteropeptidase activity (trypsin-like) and general proteolytic activity. There was no correlation between the degree of growth stimulation of the connective tissue cells and either the esteropeptidase or general proteolytic activities of any of the growth factors.