肾上腺切除幼鼠癫痫易感性及海马CRHmRNA的表达

Effect of bilateral adrenalectomy on the susceptibility to NMDA-induced seizure and hippocampal CRH m RNA in young rats

目的:探讨肾上腺切除幼鼠癫痫易感性及对海马促肾上腺皮质激素释放激素(CRH)m RNA表达的影响。方法:60只Wistar P10幼鼠随机均分为空白对照组、肾上腺切除组、假手术组。手术次日腹腔注射NMDA 7 mg/kg诱发抽搐,评价发作潜伏期(min)及程度。原位杂交方法检测海马CRH m RNA表达。结果:空白对照组潜伏期、评分为(43.65±2.96)min、4.40±0.60,肾上腺切除组为(35.05±2.35)min、5.56±0.76,假手术组为(42.60±1.90)min、4.55±0.76。肾上腺切除组与其他2组比较,潜伏期、评分差异具有显著性(F=73.73,P<0.05;F=15.52,P<0.05),3组幼鼠海马CRH m RNA阳性表达率为20%、55%、15%,与其他2组相比,肾上腺切除组海马CRH m RNA增加具有显著意义(χ2=9.048,P<0.05)。结论 :肾上腺切除幼鼠潜伏期缩短、评分增加,海马CRH m RNA提高,提示肾上腺切除幼鼠对致痫剂NMDA敏感性增高。

Objective To demonstrate the effect of bilateral adrenalectomy （ADX） on the susceptibility to NMDA-induced seizure and hippocampal CRH mRNA in young rats. Methods 60 Wistar rats at P10 were divided into control group, ADX group and Sham-ADX group. In the next day after operation, 7 mg/kg NMDA was injected to induce seizure, and incubation period （in minutes） as well as degree was evaluated. In situ hybridization was used to detect hippocampal CRH mRNA expression. Results Latency was （43.65 ± 2.96） minutes in control group, （35.05 ± 2.35）minutes in ADX group and （42.60 ± 1.90）minutes in Sham-ADX group. Latency in the ADX rats increased significantly （F = 73.73, P 〈 0.05）. The seizure scale was （4.40 ± 0.60） in control group, （5.56 ± 0.76） in ADX group and （4.55 ± 0.76） in Sham-ADX group. The severity of seizures in ADX group increased significantly compared with the control and Sham-ADX groups （F = 15.52, P 〈 0.05）. CRH mRNA expression was 20% in control group, 55% in ADX group and 15% in Sham-ADX group. CRH mRNA in the ADX group was significantly elevated （X2 = 9.048, P 〈 0.05）. Conclusion Adrenaleetomy exacerbates NMDA-induced spasm seizures in young rats, which might be related to CRH mRNA expression in the hippocampus.