Ultrastructure and membrane permeability of cultured pancreatic beta-cells exposed to alloxan or 6-hydroxydopamine.
Stereological techniques on electron microscopy micrographs were used to evaluate the morphological changes of cultured islet beta cells that had been exposed to alloxan or 6-hydroxydopamine. Trypan Blue exclusion by cells cultured for 3 days indicated that the cells were 100% viable. Electron microscopy revealed that nearly all of the surviving cultured cells were beta cells. Exposure to 5 mmol/l alloxan or 1-5 mmol/l 6-hydroxydopamine for 10 or 30 min caused a general swelling of the cultured cells with a concomitant swelling of mitochondria and nuclei. The size of the secretory granules was not affected by the drugs. Only 3-10% of the cells excluded Trypan Blue after exposure to 5 mmol/l alloxan or 6-hydroxydopamine. The data conform with the hypothesis that a primary action of alloxan and 6-hydroxydopamine is at the plasma membrane level of beta cells.
D000496:Alloxan / Q000494:pharmacology*; D000818:Animals; D002463:Cell Membrane Permeability / Q000187:drug effects; D002478:Cells, Cultured; D006892:Hydroxydopamines / Q000494:pharmacology*; D007515:Islets of Langerhans / Q000187:drug effects* / Q000502:physiology / Q000648:ultrastructure; D051379:Mice; D008820:Mice, Obese; D008854:Microscopy, Electron
D006892:Hydroxydopamines; D000496:Alloxan