Neuroprotective effects of octreotide on diabetic neuropathy in rats

The purpose of the present study is to investigate the possible healing effects of octreotide (OCT) on motor performance, electrophysiological and histopathological findings of diabetic neuropathy in a rat model of diabetes mellitus (DM). To induce diabetes, rats were administered a single dose (60 mg/kg) of streptozotocin (STZ). Diabetic rats were treated either with saline (1 ml/kg/day, n = 7) or OCT (0.1 mg/kg/day, n = 7) for four weeks. Seven rats served as control group and received no treatment. At the end of the study, electromyography (EMG), gross motor function (inclined plate test), general histology and the perineural thickness of sciatic nerve were evaluated. At the end of study, weight loss was significantly lower in OCT treated rats than that of saline treated ones (p < 0.001). Electrophysiologically, compound muscle action potential (CMAP) amplitudes of the saline treated DM group were significantly reduced than those of controls (p < 0.0001). Also, distal latency and CMAP durations were significantly prolonged in saline treated DM group (p < 0.05) compared to control. However, treatment of diabetic rats with OCT significantly counteracted these alterations in EMG. Furthermore, OCT significantly improved the motor performance scores in diabetic rats (p < 0.05). Histomorphometric assessment of the sciatic nerve demonstrated a significant reduction in perineural thickness in OCT treated group compared to saline group. In conclusion, OCT possesses beneficial effects against STZ-induced diabetic neuropathy, which promisingly support the use of OCT as a neuroprotective agent in patients with diabetic neuropathy.