Effect of alloxan on pancreatic beta cell's apoptosis in rat

Alloxan is a potent generative of reactive oxygen species (ROS), which can mediate B-cell toxicity. Reactive oxygen metabolites have been demonstrated to cause apoptotic cell death. The aim of this study was to investigate alloxan-induced morphological alterations in apoptosis. For this experimental study, wistar rats weighed 200 g were chosen and assigned into four groups of five as follows. The treatment rats received alloxan (45, 90 and 135mg/kg intraperitoneally) and control group rats received saline normal. 48 hours following the injection, pancreatic tissue samples were obtained. The selected tissue samples were fixed in 10% formalin solution and then microscopic sections with the thickness of 5-6 micron were prepared and stained with TUNEL method. Meanwhile, at 12-, 24-, 48- and 36-hour intervals blood samples were obtained from all rats to check blood sugar level. Treatment groups showed apoptotic cells in pancreatic beta cells and high blood sugar in biochemistry laboratory test in comparison with controls. Indeed, the mean number of apoptotic cells in five microscopic fields of all treated groups was significantly (p<0.001) higher than the control group. Mechanism of alloxan-induced apoptosis has not been fully understood however, evidences indicate that the pancreatic beta cell damage is mediated through the generation of cytotoxic oxygen free radicals.