간추림 실험적으로 흰쥐의 궁둥신경을 압박한 후 시간경과에 따라 역행성 변성에 의해 일어나는 몸쪽 신경의 말이집과 축삭의 미세구조적인 변화와 연역조직화학적 변화를 조사하였다.
실험동물은 Sprague Dawley 계 흰쥐를 사용하여 신경압박을 주지 않고 수술만 시행한 대조군과 수술을 하여
신경압박을 준 실험군으로 구분하였다. 실험군은 궁둥신경 1 시간 압박문 (이하 1C 군), 2 시간 압박군 (야하 2C 문 ), 3시간 압박군(이하 3C 군) 과 1 시간 압박 후 해제 1일군 (이하 IC1R), 1시간 압박 후 해제 3 일문 (이하 IC3R), 2 시간 압박 후 해제 1 일문 (이하 2CIR),2 시간 압박 후 해제 3 일군 (이하 2C3R), 3 시간 압박 후 해제 l 일군 (이하 3CIR), 3시간 압박 후 해제 3 일군 (이하 3C3R) 으로 구분하여 각 군당 10 마리씩을 배정하였으며 시간경과 후 압박부위로부터 몸쪽 말초신경의 말아정과 말이집, 축삭에 발생한 β-catenin, proliferating cell nuclear antigen (이하PCNA), substance P 의 변화와 전자현미정적인 변화를 관찰하였다.
일시적으로 궁둥신경을 압박하면 H&E 소견상 압박 초기의 옴쭉 신경병변은 축삭이 소설되었다가 회복되지만 압박기간이 걸어지면 신경성유는 심각한 손상을 나타내서 회복되지 않았다. 몸쪽 신경은 시간경과에 따라서 축삭의 소설과 β-catenin 반응의 소설과 말이집세포의 핵내 PCNA 반응이 증가하였으며 신경섬유는 커지면서 종창되였다. 압박을 해제한 후 일부 신경섬유들은 회복되고, substance P 의 반응이 냐다나, p-catenin 반응은 신경섬유의 손상이 있더라도 반응은 회복되어 민말이집형성의 회복에 중요한 역할을 하였다
이세구조적으로는 궁둥신경을 임시적으로 압박하면 몸쪽 신경에 민말이집형성, 말이집층판의 분리, 말이집세포의 공포와 변성, 축삭내 미세판의 수와 지름의 증가가 나타났으며, 압박을 해제하면 말이집세포의 발달로 신경섬유들이 회복되고 축삭내에는 사립체들과 확장된 미세관내로 운반해온 과립들이 관찰되었다.
The ultrastructural changes of sciatic nerve and immunohistochemical changes of β-catenin, PCNA, substance P were studied at the proximal segment of rat sciatic nerve after compression injury.
We used 90 Sprague Dawley rats and the sciatic nerve compressed using silicon tube. We divided experimental groups which were the compression group for 1 hour(lC), for 2 hours (2e), and for 3 hours (3C), the release group for 1 day (lCIR) and 3 days (lC3R) after the compression for I hour, the release group for 1 day (2CIR) and-3 days (2C3R) after the compression for 2 hours, the release group for I day (3CIR) and 3 days (3C3R) after the compression for 3 hours. The rats were sacrified and took the sciatic nerve specimen. The specimens were investigated under the light microscope after hematoxylin & eosin, toluidin blue, and immunohistochemical stainings.
In the H & E finding, the axon of the lC disappeared, but recovered at the lC3R. The part of nerve fibers at the 2C were swollen, but began to be partially recovered at 2C3R. Most nerve fibers were enlarged at the 3C, but markedly decreased at the 3CIR.
The β-catenin reaction disappeared at the IC, but almost recovered at the IC3R. This reaction ofthe 2C disappeared in the large fibers, but began to be recovered in the small fibers at the 2CIR. This reaction of the 3C disappeared in the large fibers, but began to be recovered at the 3CIR and 3C3R. The PCNA reaction prominently appeared at the IC3R and 2C3R, the more prominent reaction at the 3CIR, and markedly increased reaction at the 3C3R. The substance P reaction of the ICIR was mild positive, and the 2CIR and 3CIR were strong positive.
In the toluidin blue staining, the: myelin sheaths near the perineurium began to be thickened at the IC, but almost recovered at the lC3R. Many myelin sheaths became to be very thickened at the lC and 3C, but almost recovered at the 2C3R and 3C3R.
In the electron microscopic findings, the myelin sheaths of the IC underwent the demyelination with the separated lamellae and the increase microtubules. At the IC3R, the axolemma was attached on the myelin sheath and the axon was recovered. the myelin sheaths of the 2C underwent the demyelination with the separated axolemma. At the 2CIR, the myelin sheath was recovered by the developing Schwann cells, many intraaxonal mitochondria of demyelinated nerve fibers. At the 2C3R, the myelin sheath tended to be recovered by the increased rough endoplasmic reticulum and mitochondria of Schwann cells, many intraaxonal mitochondria of demyelinated nerve fibers. The myelin sheaths of the 3C began to be underwent severe demyelination from the middle portion of the sheath and the vacuolization of intraaxonal mitochondria. At the 3CIR, the myelin sheaths were recovered and contained many extended microtubules, mitochondria, and small granules. At the 3C3R, severe demyelinated nerve fibers were recovered by increasing microtubules.
The proximal retrograde degeneration of sciatic nerve by the acute compression appeared the loss of the axons and the swelling of nerve fibers. The β.-catenin reaction was disappeared by the compression, but recovered by releasing. This reaction may be played a important role of the recover of demyelination. The PCNA reaction of Schwann cells was increased by the nerve compression. In the substance P finding, the pain after the compression appeared at the 1 day after releasing.
Electron microscopic changes after sciatic nerve compression were the demyelination, the separated lamellae and the increase of intraaxonal microtubules. After releasing, the nerve fibers were recovered by developing Schwann cell, the intraaxonal mitochondria, and the transported granules through extending microtubules.