Immunohistochemical localization of insulin in pancreatic beta-cells of taurine-supplemented or taurine-depleted diabetic rats.

The purpose of this study was to observe the effects of taurine supplementation or depletion on the immunohistochemical localization of insulin in pancreas of streptozotocin-induced diabetic rats. Male Sprague-Dawley rats were fed for 7 weeks with a purified diet that was supplemented with 0, 1, 2 or 3% taurine in their drinking water. To induce taurine depletion, rats were treated with 5% beta-alanine in their drinking water. After 3 weeks, diabetes was induced by streptozotocin injection (50 mg/kg body-weight). The pancreatic tissue was stained immunocytochemically, using an antibody to insulin, and examined by light microscopy. The insulin levels in pancreatic beta-cells of the diabetic group that received no taurine-supplement were significantly decreased, compared to the non-diabetic group. The levels of insulin in beta-cell of 1% and 2% taurine-supplemented diabetic groups were significantly higher than those of the diabetic group, whereas the levels in the group receiving 3% taurine were not significantly different from that of non-diabetic rats. Therefore, it may be suggested that taurine protect pancreatic beta-cells against destruction by ptozotocin injection in a dose-dependent way.