EFFECTS OF BERAPROST SODIUM, A PROSTACYCLIN ANALOG, ON DIABETIC NEUROPATHY IN STREPTOZOTOCIN-INDUCED DIABETIC RATS

The effects of beraprost sodium (BPS), a stable prostacyclin analogue, on motor nerve conduction velocity and nerve blood flow of the sciati c nerve were investigated in streptozotocin-induced diabetic rats, and they were compared with the effects of epalrestat (aldose reductase i nhibitor). Treatment with BPS for 4 weeks significantly inhibited the decrease in motor nerve conduction velocity and nerve blood flow dose- dependently, but epalrestat had no effect on nerve blood flow. Morphol ogical changes of the myelinated fibers of the sciatic nerve were obse rved macroscopically. The mean axonal area and the mean circularity in dex of diabetic control rats were significantly less than that of norm al rats, while after 6 weeks of BPS treatment, these decreases of the axonal area and the circularity index were inhibited. The enlargement of the mean lumen area of microvessels in the diabetic rats was signif icantly inhibited after 6 weeks of BPS treatment. Additionally, augmen tation of the washed platelet aggregation in diabetic rats was signifi cantly normalized by BPS. It was suggested that BPS is effective on di abetic neuropathy via amelioration of the decrease of blood supply to the structure. The effects of BPS on platelets might also contribute t o the improvement of neuronal circulatory deficiency.