Improved neural microcirculation and regeneration after peripheral nerve decompression in DPN rats

Objective: Recently, neural microcirculation and regeneration were regarded as critical factors in diabetic peripheral neuropathy (DPN) improvement. In the present study, we explored the cytological and molecular mechanisms how peripheral nerve decompression impaired nerve injury.Methods: Forty-five male SD rats were established as the DPN model. HE staining was used to observe the morphology and distribution of microvessels. Transmission electron microscopy was applied to observe the morphology and distribution of Schwann cells. Immunohistochemical staining was performed to measure nerve growth factor (NGF), tyrosine kinase receptor A (TrkA) and growth-associated protein 43 (GAP-43) in the distal sciatic nerve.Results: Distribution of microvessels and Schwann cells decreased in the DPN group (p<0.05). NGF, TrkA and GAP-43 also decreased significantly in the DPN group (p<0.05). NGF, TrkA, GAP-43 and distribution of microvessels and Schwann cells increased in the decompressed group (p<0.05).Discussion: In DPN rats, after nerves are compressed, microcirculation disturbance and hypoxia ischemia will happen, which cause decreased expression of NGF, TrkA and GAP-43. Finally, the self-healing function of compressed nerves is impacted. Conversely, nerve decompression can improve neural microcirculation and regeneration and change the former pathological process.