[Histotopochemical and electronmicroscopical investigations of Wistar-rats with streptozotocin diabetes (author's transl)].

15 streptozotocin-diabetic wistar rats (an application of a single dose of 64 mg/kg body weight streptozotocin) and a control group of 12 wistar rats with a healthy metabolism have been examined. The majority of B-cells was largely degranulated, insulin was hardly or not to be found with histochemical methods. The A- and B-cells of 11 test animals showed pathological findings: Karyolysis, the dissolution of cell membranes and the decay of cytoplasm which are criteria of necrosis. Besides a round-cell infiltration could be found as a symptom of insulitis. The B-cells showed only single granula under the electron microscope. The endoplasmatic reticulum was only poorly developed and with hardly any ribosomes. There were only very little mitochondria and no GOLGI's apparatus. The cell membrane was smooth and not enlarged by microvilli. Emiocytosis-figures were missing. No changes of nuclei could be noticed. The findings on organelles correlate well with the microscopical results. The exocrine parenchyma contained regions showing the decay of the lobule structure as well as of single acini. The acinus cells were in necrosis. The connective tissue was obviously increased. There were regions in the stroma with a round-cell infiltration as found with a pancreatitis. Both these and the results discussed from our literature show that streptozotocin does not only affect the B-cells of the islets of LANGERHANS, but also the exocrine pancreas and other organs.