Expression And Correlation Of Nmdar1,caspase-3 After Spinal Cord Ischemia Injury In Rabbit

Objective: To study the diversity expression of N-methyl–D–aspartate receptor 1(NMDAR1) and Caspase-3 in the spinal cord ischemia of rabbit and the correlation between NMDAR1 and Caspase-3.Methods: Fourty-eight rabbits were randomly devided into six groups as follows:sham-operated group and operated groups(n=8 at each time point) at designated times(6,12,24,48,72 hours after the ischemia surgery).The ischemia model was developed by selectively ligation of the five lubar arteries just inferior to the left renal vein and above the bifurcation. The mRNA and protein expression level of NMDAR1,Caspase-3 in differerent times after the ischemia surgery were separately detected by reverse transcriptase-polymerase chain reaction( RT-PCR) and Western-blot ;at the same time ,where the NMDAR1,Caspase-3 located in the cell was detected by immunohischemistry. The relationship between the two elements(NMDAR1,Caspase-3) were analysed by SPSS17.0.The criterion for statistical significance was P <0.05 in all cases.Results: The immunohistochemistry results showed that NMDAR1,Caspase-3 were mainly located in the cytoplasm;they were low expressed in sham-operation group. The relative expression level of NMDAR1 in mRNA and protein was as follows: 0.089±0.01, 0.202±0.07, 0.367±0.01, 0.442±0.08, 0.548±0.18, 0.790±0.07; 0.072±0.04, 0.132±0.01, 0.221±0.02, 0.360±0.03, 0.489±0.05, 0.688±0.09. The relative expression level of Caspase-3 in mRNA and protein was as follows: 0.070±0.09, 0.163±0.03, 0.281±0.04, 0.407±0.06, 0.510±0.07, 0.726±0.04;0.031±0.03,0.073±0.02, 0.143±0.05, 0.244±0.04, 0.447±0.03, 0.639±0.18,there was significant difference between groups(P <0.05);meanwhile,the correlation analysis indicated that there were positive correlation relation between NMDAR1 mRNA and protein( r=0.854, P<0.05),the same to Caspase-3(r=0.964, P<0.05).Furthermore, there were positive correlation relation between NMDAR1 and Caspase-3(r=0.931, P<0.05)in mRNA; there were positive correlation relation between NMDAR1 and Caspase-3(r=0.986, P<0.05)in protein.Conclusion:1.The expression of NMDAR1 and Caspase-3 were time-related to spinal cord ischemia, may be invoived in the pathological progression of spinal cord ischemia.2.The express of Caspase-3 in spinal cord ischemia was related to NMDAR1. they may coordinate with each other in the procession of spinal cord ischemia development. NMDAR1 may regulate Caspase-3 to the pathological procession of spinal cord ischemia.