اثرات لواستاتين بر پاسخ هاي اتساعي استيل كولين در بستر عروقي مزانتررتهاي ديابتي شده با استروپتوز و توسين

Effect of lovastatin on acetylcholine induced relaxation in the isolated mesenteric bed of strcptozotocin diabetic rats

We have investigated the acute effect of lovastatin on diabetes-induced endothelial dysfunction in the isolated mesenteric bed of streptozotocin-diabetic (STZ) rats. The endothelial function was tested in constantly perfused preparations isolated from rats, 12 weeks after treatment with STZ (45 mg kg, i.p.).All preparations were precontracted by Phenylephrine 10ʹ4 M .Acetylcholine (ACh) induce relaxation in perfused mesenteric bed dose dependently. Response to Ach was reduced in diabetic group significantly. Co-perfusion with lovastatin (10 -5 M, for 15 min) significantly improved the Ach-mediated relaxation removed from diabetic but not control rats. However, this beneficial effects of lovastatin was inhibited by pre-incubation of tissue with L-NAME (5 x 10-ʹ M, for 20 min), but not indomethacin (10 -5M). The vasodilatory responses to sodium nitroprusside from control or diabetic rats were unchanged by lovastatin pretreatment. From the present results it may conclude that lovastatin significantly improves endothelial-dependent relaxation in diabetic group. It could be via increasing nitric oxide bioavalibity, most probably due to its antioxidant effects.