Islet cell subpopulations in cultured mouse fetal pancreas and pancreatic isografts.

Application of the immunoperoxidase technique proved very rewarding in determining the structure and function of cultured fetal pancreas and isografted tissue. Proliferation of endocrine beta-cells was highest during the first three weeks of culture but these cells rapidly declined in number thereafter as the delta-cell mass increased. Morphologically, the optimal culture time, based on beta-cell mass, was approximately ten to 14 days and this did not appear to be dependent on whether the tissue was cultured under conventional or high oxygen conditions. It is hoped that electron microscopy may reveal the fate of the diminishing population of insulin-producing cells. Immunoperoxidase staining of long-term isografts demonstrated the presence of large islets with the typical morphologic structure of normal adult pancreatic islets. It is believed that this may be of vital importance if pancreatic islet transplantation is to be fully effective in the control of blood glucose levels, which it is hoped will help prevent the longterm diabetic complications associated with insulin-dependent diabetes.