Effects of Beraprost Sodium and Insulin on the Electroretinogram, Nerve Conduction, and Nerve Blood Flow in Rats with Streptozotocin-Induced Diabetes

Abstract

The effect of a prostacyclin analog, beraprost sodium, on the electroretinogram, motor nerve conduction velocity, and nerve blood flow was determined in rats with streptozotocin-induced diabetes and was compared with the effect of insulin. Beraprost sodium (0.01 mg x kg-1 x day-1 for 8 weeks) significantly shortened the peak latency of the electroretinogram b-wave, increased tail nerve conduction velocity, and increased sciatic nerve blood flow in diabetic rats (P < 0.0003, 0.0001, and 0.0001 vs. untreated diabetic rats, respectively). This was accompanied by a significant increase in the 6-keto-prostaglandin F1alpha content of the thoracic aorta and a marked increase in the cAMP content 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 suggest that beraprost sodium may be useful for prevention of vascular and neural dysfunction in the retina and peripheral nerve.