Change of spinal neuronal nitric oxide synthase expression in rats with painful diabetic neuropathy / 南方医科大学学报

ABSTRACT

<p><b>OBJECTIVE</b>To observe the change of neuronal nitric oxide synthase (nNOS) expression in the spinal cord of diabetic rats with painful diabetic neuropathy.</p><p><b>METHODS</b>Sixty SD rats were randomized equally into painful diabetic neuropathy group (DM group) and control group. Painful diabetic neuropathy was induced by intraperitoneal injection with STZ (60 mg/kg) in DM group, and the rats in the control group received a solvent injection. Blood glucose levels were measured before and at 2, 7, 14, 21, and 28 days after STZ injection (T1-6 respectively). Responses to the mechanical stimulus were measured with von Frey filament, and 50% paw withdraw threshold (PWT) and body weight were recorded at T1 and T3-6. At T1 and T3-6, 6 rats from each group were sacrificed to examine the expression of nNOS in the lumbar segments of the spinal cord using Western blotting.</p><p><b>RESULTS</b>The level of blood glucose increased while the body weight decreased significantly after STZ injection in DM group (P<0.05). Comparing to those in the control group, PWT decreased while spinal nNOS expression increased significantly in DM group at T4-6 (P<0.05) showing an inverse correlation between them (P<0.01).</p><p><b>CONCLUSION</b>The enhanced expression of spinal nNOS might be involved in the pathogenesis of painful diabetic neuropathy in rats.</p>