Gülriz Ersöz1, Ali Yakaryilmaz, Belma Turan. 1. Department of Physiology, Faculty of Medicine, Ankara University, 06100 Sihhiye, Ankara, Turkey. geroz@medicine.ankara.edu.tr
Abstract
INTRODUCTION: There is a well-known association between diabetes and atherosclerosis. Platelets are involved in the development of atherosclerotic vascular diseases and play a key role in atherosclerotic complications. Diabetes mellitus is related to alteration in the homeostasis of selenium and the protective role of selenium against lipid peroxidation in diabetes is reported. In the present study, thrombin-induced platelet aggregation and thromboxane A2 (TxA2) formation in diabetes and the effect of sodium selenite were evaluated. MATERIALS AND METHODS: Diabetes was induced by intraperitoneal injection of streptozotocin (STZ) in Wistar rats (n = 21). Thirty of them were used as control rats. A week after streptozotocin injection, 11 of the control rats and 12 of the diabetics were injected with 5 micromol/kg/day of sodium selenite for 4 weeks. Thrombin-induced aggregation of the platelets was evaluated by optical technique. Thromboxane B2 (TxB2), TxA2 metabolite, was measured by enzyme-linked immunoassay (EIA) in thrombin-induced platelets. RESULTS AND CONCLUSION: The platelet aggregation and TxB2 level increased in diabetic rats. Sodium selenite reversed the increase in platelet aggregation and TxB2 and caused a small but significant (p < 0.05) decrease in the glucose level. The hyperaggregability of platelets in STZ-induced diabetic rats was thought to be related to the enhanced TxA2 formation of platelets. Increase in TxA2 formation implies lipid peroxidation. Sodium selenite decreased the TxA2 formation. Besides its antioxidative effect, further studies are needed to establish the insulin-like effect of selenite because of a small decrease in blood glucose.
INTRODUCTION: There is a well-known association between diabetes and atherosclerosis. Platelets are involved in the development of atherosclerotic vascular diseases and play a key role in atherosclerotic complications. Diabetes mellitus is related to alteration in the homeostasis of selenium and the protective role of selenium against lipid peroxidation in diabetes is reported. In the present study, thrombin-induced platelet aggregation and thromboxane A2 (TxA2) formation in diabetes and the effect of sodium selenite were evaluated. MATERIALS AND METHODS:Diabetes was induced by intraperitoneal injection of streptozotocin (STZ) in Wistar rats (n = 21). Thirty of them were used as control rats. A week after streptozotocin injection, 11 of the control rats and 12 of the diabetics were injected with 5 micromol/kg/day of sodium selenite for 4 weeks. Thrombin-induced aggregation of the platelets was evaluated by optical technique. Thromboxane B2 (TxB2), TxA2 metabolite, was measured by enzyme-linked immunoassay (EIA) in thrombin-induced platelets. RESULTS AND CONCLUSION: The platelet aggregation and TxB2 level increased in diabeticrats. Sodium selenite reversed the increase in platelet aggregation and TxB2 and caused a small but significant (p < 0.05) decrease in the glucose level. The hyperaggregability of platelets in STZ-induced diabeticrats was thought to be related to the enhanced TxA2 formation of platelets. Increase in TxA2 formation implies lipid peroxidation. Sodium selenite decreased the TxA2 formation. Besides its antioxidative effect, further studies are needed to establish the insulin-like effect of selenite because of a small decrease in blood glucose.