The changes of expression of NMDA receptors in spinal dorsal horn neurons in rats with diabetic neuropathic pain

Objective To investigate the changes of expression of NMDA receptors in spinal dorsal horn neurons in rats with diabetic neuropathic pain (DNP).Methods Twenty-four male SD rats (4-week age,weighed 130~150g ) were randomly divided into two groups:control group (n=9),DNP group (n=15).The DNP models were established by peritoneal injection with streptozotocin (STZ,50mg/kg) in DNP group,however,instead of STZ the equal volume of 0.9% sodium chloride solution was injected in control group.At 3,5,7 weeks after the injection the 5 rats in DNP group and 3 rats in control group were taken to be weighed.and the fasting blood glucose levels and paw withdraw threshold (PWT) were measured,and the expression levels of NR1 and NR2B subunits receptors in spinal dorsal horn neurons were detected by immunohistochemistry.Results As compared with those in control group,the rat’s body weight in DNP group was decreased,however,the rat’s blood glucose was increased,especially,PWT was significantly reduced (P0.05),and the expression levels of NR1 and NR2B subunits receptors in spinal dorsal horn neurons were significant increased (P0.05).Conclusion The NMDA receptor in spinal dorsal horn neuron is involved in the pathogenesis of diabetic neuropathic pain in rats.