FACTORS CONTROLLING PANCREATIC-ISLET NEOGENESIS

We have established a model in which cellophane wrapping induces reite ration of the normal ontogeny of beta-cell differentiation from ductal tissue. The secretion of insulin is physiologic and coordinated to th e needs of the animal. Streptozotocin-induced diabetes in hamsters can be 'cured' at least half the time. There appears to be activation of growth factor(s) within the pancreas acting in an autocrine, paracrine or juxtacrine manner to induce ductal cell proliferation and differen tiation into functioning beta-cells. Given the results of our studies to date, it does not seem premature to envisage new approaches to the treatment of diabetes mellitus. Identification of the factor(s) which regulates islet cell proliferation and differentiation in our model ma y permit proto-undifferentiated cells and islets to be grown in cultur e. This concept could be extended to induce endocrine cell differentia tion in vitro as well. Furthermore, islet cell growth factors could be used to provide 'trophic support' to islet transplants as a means of maintaining graft viability. There may also be greater scope for gene therapy when the growth factor(s) has been isolated, purified, sequenc ed and cloned.