Influence of Intracerebroventricular Injection of Nociceptin/Orphanin FQ On Cerebral Infarction Volume and Somatosensory Evoked Potential in Focal Cerebral Ischemia in Rats / 国际脑血管病杂志

ABSTRACT

OyecaveTo observe the influence of nociceptin/orphanin FQ(N/OFO)on cerebral infarction volume and somatosellsOry evoked potential(SEP)in focal cerebral ischemia in rats.Methods:Forty one SD rats were randomly alloomed into middle artery occlusion(MCAO)sham-operation(n=5),isehemic(n=8),N/OFQ 10μg(n=7),N/OFQ 1 μg(n=7),N/OFQ0.1 μg(n=7),and artificiai cerebrospinal fluid(ACSF)(n=7)groups.A model of middle cerebral artery occlusion(MCAO)in rats was induced using intraluminal suture method.Reperfusion was performed 2 hours after MCAO.One hour after MCAO,N/OFQ 10 μg,N/OFQ 1 μg,N/OFQ O. 1 μg,and the same volume of ACSF were injected intraventricularly in the N/OFQ 10 μg,N/OFQ 1 μg,N/OFQ 0. 1 μg,and ACSF groups,respectively. The cerebral infarction volurne was detected 24 hours after reperfusion,and SEP was recorded. Results:1he amplitude of SEP P1 decreased in the sham-operation group. There was no significant change in P1 peak latencies.There were no significant differences hetween the N/OFQ 0. 1 μg group and the ACSF group in SEP amplitudes,P1 peak lantecies and cerebral infarction volume. As compared with the ACSF group,the SEP amplitudes were further decreased in the N/OFQ 1 μg and N/OFQ 10 μg groups,but there were no significant change in P1 peak lantecies. One hour after reperfusion,the SEP amplitude in the ACSF group almost returned to the level of preischemia,the recovery slowed down in the N/OFQ 1 μg group,and it still did not recovered 3 hours after reperfusion in the N/OFQ 10 μg group. The dose of N/OFQ and SEP response showed dose-effect relationship,The higher the dose,the deeper the SEP depression and the slower the recovery. At 24 hours after reperfusion,the cerebral infarction vlumes in the shamoperation,ACSF,N/OFQ 0. 1 μg,N/OFQ 1 μg,and N/OFQ 10 μg groups were 0 mm3,24.180 ±4.088 mm3,23.090±4.523 mm3,35.304 ± 6. 824 mm3,and 40. 806±6. 716 mm3,respectively. There was no significant difference between N/OFQ 0. 1 and ACSF groups. There were significant differences between N/OFQ 1 μg and 10 μg groups and ACSF group (all P ＜ 0.01 ). Conclusions:Intracerebroventricular injection of N/OFQ in the early stage of cerebral ischemia decreases the SEP amplitude,prolongs the time of recovery,and increases cerebral infarction volume,which shoves that it may aggravate cerebral ischemic injury.