Ultrastructural aspects of streptozotocin cytotoxicity on rat pancreatic islets in vitro. Test of a protective effect of zinc.
Pancreatic islets, newly formed in vitro were incubated in the presence of streptozotocin (STZ; 0.4 mM) for up to 6 h. Ultrastructural changes first appeared between 2 and 4 h; heterochromatization, was followed by swelling of nuclear and reticular membranes, vesiculation of the Golgi apparatus, fragmentation of cell membranes and finally mitochondrial destruction. At the end of the experiment all the B cells were destroyed, whereas the other cell types remained intact. Exogenous ZnSO4 was added during preincubation periods to increase the intrainsular zinc content and to determine any protective effect against STZ-cytotoxicity. Since the addition of zinc had no obvious effect, it is suggested that STZ cytotoxicity on B cells cannot be attributed to competition for zinc between copper-zinc superoxide dismutase (Cu-Zn-SOD) and the crystallization of insulin.
D000818:Animals; D000831:Animals, Newborn; D046508:Culture Techniques; D007515:Islets of Langerhans / Q000187:drug effects* / Q000648:ultrastructure; D008854:Microscopy, Electron; D051381:Rats; D011919:Rats, Inbred Strains; D013311:Streptozocin / Q000009:adverse effects*; D013431:Sulfates / Q000494:pharmacology*; D015032:Zinc / Q000494:pharmacology*; D019287:Zinc Sulfate
D013431:Sulfates; D013311:Streptozocin; D019287:Zinc Sulfate; D015032:Zinc