ABSTRACT
Objective To observe the effect of spinal cord stimulation on expression of spinal GLT-1 and GLAST in rats with diabetic neuropatbic pain.Methods Forty-eight healthy male SD rats,only 2 months old,weighting 250-300 g,using the random number table method,were divided into four groups (n=12):the control group (group C),diabetes neuralgia group (group D),false stimulation group (group N)and spinal cord stimulation group (group S).The model of diabetes was induced by the pedtoneal injec-tion of streptozocin (STZ),electrodes were placed into the epidural space 1 9 days after injection of STZ in groups N and S,in addition,group S was performed 26-28 days after injection of STZ.Mechanical contrac-tion leg threshold (MWT)were determined one day before STZ injection,2 d,7 d,14 d and 28 d after STZ injection.The rats were sacrificed,the lumbar spinal cord tissue were obtained for determination of GLT-1 and GLAST expression in spinal cord tissues on 28 d after measurement of MWT.Results Compared with group C,MWT was decreased 14 d and 28 d after STZ injection,and expression levels of GLT-1 and GLAST mRNA were increased on 14 d and 28 d (P<0.05);Compared with before STZ injection,MWT of group D,group N and group S was decreased on 14 d and 28 d (P<0.05);Compared with group D, MWT was increased,and expression levels of GLT-1 and GLAST mRNA were increased in group S on 28 d after STZ injection (P<0.05 ).Conclusion The mechanism of spinal cord stimulation reducing rats diabetes neuralgia may be related to elevating the expression of GLT-1 and GLAST.
ABSTRACT
Objective To evaluate the effect of spinal cord stimulation on the expression of neuronal nitric oxide synthase (nNOS) in the rats with diabetic neuropathic pain.Methods Forty-eight pathogen-free healthy male Sprague-Dawley rats,aged 2 nonths,weighing 250-300 g,were divided into 4 groups (n =12 each) using a random number table:control group (group C),diabetes mellitus group (group DM),sham operation group (group S) and spinal cord stimulation group (group SCS).Diabetic neuropathic pain was produced by intraperitoneal injection of 1％ streptozocin 75 mg/kg and confirmed by blood glucose level＞16.7 mmol/L on day 2 after streptozocin injection.Electrodes were implanted into the epidural space at 19 days after successful establishment of the model in S and SCS groups,and in addition spinal cord stimulation (frequency 50 Hz,pulse width 0.2 ms,intensity=2/3 of the lowest intensity) was performed for 30 min once a day at 26-28 days after successful establishment of the model in group SCS.The mechanical paw withdrawal threshold (MWT) was measured at 1 day before establishment of the model (T1) and 2,7,14 and 28 days after successful establishment of the model (T2-5).The rats were sacrificed after the last measurenent of MWT at T5,and the lumbar segment of the spinal cord was removed for determination of nitric oxide (NO) content and nNOS expression in spinal cord tissues.Results Compared with group C,the MWT was significantly decreased at T4.5,and the NO content and nNOS expression in the spinal cord were increased in DM,S and SCS groups (P＜0.05).Compared with group DM,the MWT was significantly increased at Ts,and the NO content and nNOS expression in the spinal cord were decreased in group SCS (P＜0.05).Conclusion The mechanism by which spinal cord stimulation allenuales diabetie neuropalhic pain is related to inhibiting nNOS expression and reducing NO production in rals.