EFFECTS OF BERAPROST SODIUM AND INSULIN ON THE ELECTRORETINOGRAM, NERVE-CONDUCTION, AND NERVE BLOOD-FLOW IN RATS WITH STREPTOZOTOCIN-INDUCED DIABETES

The effect of a prostacyclin analog, beraprost sodium, on the electror etinogram, motor nerve conduction velocity, and nerve blood flow was d etermined in rats with streptozotocin-induced diabetes and was compare d with the effect of insulin. Beraprost sodium (0.01 mg . kg(-1). day( -1) for 8 weeks) significantly shortened the peak latency of the elect roretinogram b-wave, increased tail nerve conduction velocity, and inc reased sciatic nerve blood flow in diabetic rats (P < 0.0003, 0.0001, and 0.0001 vs. untreated diabetic rats, respectively). This was accomp anied by a significant increase in the 6-keto-prostaglandin F-1 alpha content of the thoracic aorta and a marked increase in the cAMP conten t of the sciatic nerve. Beraprost sodium had no effect on the sorbitol and fructose contents of the sciatic nerve and retina, but insulin (8 -10 U/day) significantly reduced both parameters. These findings sugge st that beraprost sodium may be useful for prevention of vascular and neural dysfunction in the retina and peripheral nerve.