흰쥐 척수손상에서 Tempol의 효과 및 작용기전 = Effects of Tempol, A Nitroxide Antioxidant in a Rat Model of Spinal Cord Contusion Injury

다국어 초록 (Multilingual Abstract)

Reactive oxygen species (ROS) have been implicated in the pathogenesis of various kinds of pathologic conditions in the central nervous system including ischemia-reperfusion injuries, infectious diseases, and traumatic injuries and appear to participate in the final common pathway of neuronal death. 4-Hydroxy-2,2,6,6- tetramethyl-piperidinyl-1-oxyl (Tempol) is a small molecular stable nitroxide and has been known as a membrane-permeable antioxidant which reacts as a free radical scavenger with proven protective efficacy in several animal models with brain injuries. The aims of this study were to investigate the biologic effects and reaction mechanisms of tempol, focused on the antiinflammatory effect and generation of nitric oxide, in the spinal cord contusion injury (SCI). The animal model of SCI was performed by weight drop impact using a 10 g rod (2.0 ㎜ in diameter) dropped at a height of 25 ㎜ and observe the expression of COX-2, as a generator of potent inflammatory mediators, prostanoids and iNOS which is responsible for production of large amount of nitric oxide (NO) during secondary injury of SCI. After contusion injury, the relative amounts of COX-2 and iNOS mRNA and protein were peaked at 8 h postinjury, and then decreased up to 7 d postinjury, return to normal level at 14 d postinjury. Expression of COX-2 protein was peaked at 8 h postinjury. With the tempol pretreatment the immunoreactivity of COX-2 and nitrotyrosine in paraffin embedded tissue slices were profoundly decreased. Irreversibly damaged areas of spinal cord were peaked at 3 d after SCI. With the tempol pretreatment, the irreversibly damaged areas were profoundly decreased with statistical significance at 3 d after SCI.
From the above results it is concluded that tempol pretreatment can reduces irreversibly damaged areas on the spinal cord contusion injury in rat. The mechanisms of biologic reactions of tempol may be related with the decreased expression of COX-2 and iNOS in the spinal cord cells, both neurons and glia. It is concluded that the reaction mechanisms of tempol on the spinal cord injury may be not only due to antioxidant activity but antiinflammatory reaction.

목차 (Table of Contents)

• 목차
• 1. 서론 = 1
• 2. 재료 및 방법 = 5
• 2.1. 척수좌상의 실험동물모델 = 5
• 2.2. iNOS, COX-2 mRNA의 실시간 정량 분석 = 5
• 2.2.1. 전체 RNA 분리 = 5
• 2.2.2. First strand cDNA 합성 = 6
• 2.2.3. 실시간 정량 RT-PCR = 6
• 2.3. Western blot analysis = 7
• 2.4. 형태학적 검사 = 8
• 2.4.1. 광학현미경 검사 및 손상면적 측정 = 8
• 2.4.2. Nitrotyrosine과 COX-2에 대한 면역조직화학검사 = 8
• 3. 성적 = 10
• 3.1. 척수좌상의 광학현미경 소견 및 비가역적 손상면적의 비교 = 10
• 3.2. Tempol 투여가 척수좌상 조직의 COX-2 mRNA 및 단백의 발현에 미치는 효과 = 10
• 3.3. Tempol 투여가 척수좌상 조직의 iNOS 발현 및 NO 생성에 미치는 효과 = 11
• 4. 고찰 = 13
• 5. 요약 = 17
• 6. 참고문헌 = 18
• 사진부도 = 23
• Abstract = i