摘要
目的:观察大鼠高位脊髓损伤后,脊髓损伤段及其邻近上下段α1 肾上腺素受体表达的变化,旨在探讨临床自主高反射下严重高血压发生的可能机制。方法:健康雄性Wistar大鼠42只,随机分为2 组:假手术组(6 只)和脊髓损伤组(36 只)。采用改良Allens打击法,建立脊髓T4节段重度损伤动物模型。假手术组仅咬除椎板,未打击脊髓。分别于损伤后1 d、3 d、1周、2周、3周和4周各处死脊髓损伤动物6只,取损伤段及邻近上下段脊髓,假手术组亦取相应不同节段脊髓组织。采用RT PCR法测定脊髓不同节段α1 肾上腺素受体mRNA表达情况。结果:与假手术组相比,脊髓损伤段以上节段在损伤后1 d受体表达无明显变化,但3 d后表达减少(P<0.05),1周时降至最低(P<0.01),此后表达开始增加,2 周时与假手术组无明显差异,至损伤后4周受体表达未见明显变化;损伤段在损伤后受体表达持续减少(P<0.05),损伤后1周达最低(P<0.01),此后受体表达开始逐步增加,但至损伤后4周仍未超过假手术组(P<0.05);损伤段以下节段在损伤后1 d受体表达显著减少(P<0.01),损伤后3 d受体表达接近假手术组,此后受体表达持续增加,至损伤后4 周受体表达超过假手术组(P<0.05)。结论:大鼠高位脊髓损伤4周后,脊髓损伤段以下节段α1 肾上腺素受体表达增加。α1 肾上腺素受体数目上调?
Objective:To observe the changes of α 1 -adrenergic receptors expression in a high-level spinal cord injury (SCI) rat model,providing information for studying the mechanisms of severe hypertension of autonomic dysreflexia.Methods: Adult male Wistar rats were divided into 2 groups: sham-lesion group(n=6) and SCI group(n=36). Severe spinal crush injury was induced at T 4 using modified Allens device in SCI group, while sham-lesion group received laminectomy at T 4 only.The expression of α 1 -adrenergic receptors mRNA in different segments of spinal cord:injured segment(I), above(A) and below(B) the injured site, were measured by reverse-transcription polymerase chain reaction (RT-PCR) 1 d, 3 d, 7 d, 2 weeks, 3 weeks and 4 weeks after SCI. Results: Compared with sham-lesion group,the express of α 1 -adrenergic receptors mRNA in group A decreased 3 d after SCI and dropped to the least 1 week later,and restored to the normal level 2 weeks later.The impairment of α 1 -adrenergic receptors mRNA expression in group I occured immediately after SCI and hit the lowest value 3 d later,and did not recover to the nomal 4 weeks later.Decrease of α 1 -adrenergic receptors mRNA expression in group B were detected 1 d after SCI,but began to increase on 3 d and exceeded that of group C 4 weeks later.Conclusion: In chronic SCI rat models α 1 -adrenergic receptors expression increases below the level of SCI,which might be a contributing factor to the severe hypertension of autonomic dysreflexia.
出处
《第二军医大学学报》
CAS
CSCD
北大核心
2005年第3期323-326,共4页
Academic Journal of Second Military Medical University
基金
上海市卫生局科技发展基金(024097)
