[Early death of pancreatic A-cells after irradiation with supralethal doses]

For investigation of postirradiation reactions, of pancreatic insular cells, male Wistar rats were subjected to 1.5, 3, 7, and 15 kR of Co60 gamma-radiation. It was found that after application of doses of 7 kR or higher, interphase death of all the insular A-cells occurred within 6 hours. The cell death was demonstrated to be characterized by chromatin pycnosis, dilatation of the endoplasmic reticulum and perinuclear space, mitochondrial swelling, and desintegration of A-granules. Macrophages took no part in resorption of the dead cells. A-cell necrosis was not accompanied by morphologically observable changes in acinar cells or insucar B-cells. Some possible explanations of the more pronounced radiosensitivity of A-cells are discussed.