The Effect of Endurance Training on Fibronectin Gene Expression of the Sciatic Nerve in Diabetic Rats

Diabetic neuropathy can cause disorders in axon transmission, changes in the extracellular matrix, and peripheral nerve damages. However, its mechanism, along with the beneficial effects of exercise on these disorders is not entirely clear. The aim of the current study was to assess changes in fibronectin mRNA gene expression level of the sciatic nerve in rats with streptozotocin-induced diabetes after endurance training. Eighteen male Wistar rats (10 weeks old with 250±20 gr weight) were randomly assigned to three groups, including healthy, induced diabetes and induced diabetes plus endurance training. Induction of diabetes was conducted using an intraperitoneal injection of a single dose of streptozotocin (STZ). Neuropathy was confirmed using the behavioral tests. Rats in induced diabetes plus training group had 8 weeks of moderate and increasing intensity endurance training on the treadmill. The Fibronectin mRNA gene expression level of the sciatic nerve was assessed using Real-time-PCR. Changes in fibronectin protein and myelin thickness were measured by immunohistochemistry and luxol fast blue staining. The mean and standard deviation was used to report descriptive data. Data were entered into SPSS 22. Fibronectin mRNA gene expression level (1.90) of sciatic nerve fibronectin protein and myelin thickness reduced significantly due to diabetes (P<0.05). Eight weeks of endurance training increased fibronectin gene expression of sciatic nerve fibronectin protein and prevented further destruction of myelin, which was statistically significant. The results showed that diabetes leads to changes in the extracellular matrix and the reduction of the sciatic nerve myelin thickness. Endurance training as a non-drug strategy is effective in preventing these damages.