Effects of cyclosporin A on the endocrine pancreas of the rat. Morphological and immunohistochemical studies.

Treatment with the immunosuppressive agent cyclosporin A frequently gives rise to functional alteration of the islets of Langerhans which may result in diabetes. Light microscopy, immunocytochemical, and electron microscopy investigations demonstrate degranulation, vacuolization, and destruction of endocrine pancreatic cells in treated animals. Similar changes, but of a milder degree, are observed in the A-cells. The morphological alterations described are likely to be the result of inhibition of synthesis and secretion in B-cells.