흰쥐에서 척수신경 앞뿌리 찢김에 의한 척수 앞뿔 세포의 형태학적 변화 = Morphological Changes of Anterior Horn Cells of Lumbar Spinal Cord after Anterior Root Avulsion in Adult Rat

국문 초록 (Abstract)

성숙한 흰쥐를 대상으로 운동신경세포의 사멸과정과 그에 따른 형태학적 변화를 확인하기 위하여 Sprague-Dawley계 수컷 흰쥐의 넷째와 다섯째 허리신경의 앞뿌리를 뜯어내고 5일, 1주, 2주 및 3주 후에 동물을 희생시켜 척수 앞뿔에서 나타나는 변화를 관찰하였다. 앞뿌리를 뜯어낸 쪽을 실험쪽, 그 반대쪽을 대조쪽으로 하였다. 신경계 세포의 형질 변화를 확인하기 위하여 일차항체로는 choline acetyltransferase (ChaT), ED-1, vascular endothelial growth factor (VEGF), glial fibrillary acidic protein (GFAP)에 대한 항체를 사용하여 면역조직화학법을 실시하였다.
1. ChaT 면역반응 운동신경세포의 수는 손상 3주군에서 대조쪽의 20% 수준이었다.
2. ED-1 면역반응의 미세아교세포는 손상 1주군의 실험쪽에서 가장 많이 발현하였으며, 미세아교세포의 돌기는 손상받은 신경세포체 주위를 감싸고 있었다.
3. 손상 2주군에서 GFAP 면역반응 별아교세포의 증식은 대조쪽과 실험쪽 모두에서 관찰되었지만, 실험쪽이 더 현저하였다. 그러나 VEGF 면역반응 세포의 발현은 대조쪽에 비하여 실험쪽에서 유의하게 증가되어 있었다.
이상의 결과에 의하여 성숙한 동물의 척수신경 앞뿌리를 뜯어내면 척수 앞뿔에 위치하는 ChaT 면역반응 운동신경세포의 사멸과 더불어 ED-1 면역반응의 미세아교세포와 GFAP 면역반응의 별아교세포의 증식과 더불어 VEGF 면역반응의 신경아교세포의 증식을 형태학적으로 확인하였다.

다국어 초록 (Multilingual Abstract)

The morphological changes in the anterior horn of the L4 and L5 spinal segments were observed following anterior root avulsion in the adult male Sprague-Dawley rat (300~350 gm) at 5 days, 1 week, 2 weeks and 3
weeks postlesion. The animals were perfused with 4% paraformaldehyde, 0.15% picric acid in 0.1 M phosphate buffer solution and cryostat sections were prepared. Immunohistochemistry was used to identify changes of the phenotype in the anterior horn cells. Primary antibodies, goat anti-choline acetyltransferase (ChaT, 1 : 500, Chemicon), mouse antirat ED-1 (1 : 200, Serotec), rabbit anti-glial fibrillary acidic protein (GFAP, 1 : 200, DAKO) and rabbit anti-vascular endothelial growth factor (VEGF, 1 : 500, Santa Cruz Biotechnology) were used. Avidin-Biotin complex method was performed for immunohistochemical reaction and color reaction was developed with DAB-H2O2. Following results were observed in the anterior horn of lumbar spinal cord;
1. The number of ChaT-immunoreactive (ir) cells were reduced 20% level of control animals at 3 weeks after
avulsion.
2. ED-1-ir microglia were significantly increased at 1 week and processes of ED-1-ir microglia surrounded around
the axotomized neuronal cell bodies.
3. Gliosis defined by extensive GFAP immunoreactivity was observed both ipsilateral and contralateral side of
lesion but the VEGF-ir cells were significantly increased in the ipsilateral side of lesion.
Therefore, this study suggested that the majority of axotomized motor neurons were degenerated and the cellular
proliferation and phenotype changes including glial cell activation were observed in the lumbar spinal cord after anterior root avulsion of adult rats.

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