고양이 망막에서 5,7- DHT에 의한 신경절세포의 사멸과 미세아교세포의 반응양상

다국어 초록 (Multilingual Abstract)

This study was designed to clarify the neurotoxic effects of 5,7-dihydroxytryptamine (5,7-DHT) on the ganglion cells, and to investigate the microglial reactions to the neurodegenerative changes in the cat retina. All experiments were performed using adult cats of both sex, weighing 2,500 g - 3,500 g. 5,7-DHT(100㎍) dissolved in 0.9% Nac1 was injected into the vitreous body. All injections were performed in one-side eye ; the other side served as the control, which was injected only with 0.9% Nacl.cats were sacrificed at 1, 3, 7, 14 and 21 days after intravitreal injection of 5,7-DHT.
Most of the 5,7-DHT accumulating cells were undergone typical dark degeneration. That is, the cells were characterized by widening of the cellular organelles at early stage, and by darkening of the cytoplasm at late stage. The population of the degenerated cells in the GCL was peak at 14 day after the drug injection, but thereafter slightly decreased at 21 day. Most of the degenerated cells were phagocytosed by microglial cells in the cat retina, but some removed by astrocytes.
NDPase-positive microglial cells were mainly distributed in the inner plexiform layer of the retina, and characterized by a small somata with a few slender processes, which were also extended in the GCL and inner nuclear layer (INL). The intensity of the microglia stained for NDPase was abruptly increased at 7 day as compared with that of the control, and thereafter continuously sustained until 21 day, the last experimental group in this study. In addition, the processes of NDPase-positive microglial cells became more short and thick after ter 7day.
Under the electron microscopical observation, microglial cells in the control group exhibited elongate nucleus with perinuclear chromatin condensation,m and the perikaryon was scanty, containing strands of RER(rough endoplasmic reticulum). However, a few hypertrophic glial cells acquired abundant cytoplasm, were frequently found at 3 days after the drug injection. By 7 dya, most microglial cells began to migrate toward the degenerated neurons in the GCL, and the number of microglial cells was slightly increased by proliferation as compared with the former group. AT the 14 day, most microglial cells wraped the degenerated cells in the GCL, and a few cells showed active phagocytotic features. By 21 day, most microglial cells were engaged in phagocytotic activity, and their cytoplasm was filled with the phagocytosed matrial.
Based on the results, 5,7-DHT may act as a specific neurotoxin to a part of ganglion cells in the cat retina, and microglial reactions to the neuronal death prevailed in early experimental stage. The results indicate that the microglial cells in the cat retina show characteristic features as glial reaction to particular type of neuronal death.

목차 (Table of Contents)

• 목차 = 0
• Ⅰ. 서론 = 1
• Ⅱ. 재료 및 방법 = 5
• Ⅲ. 결과 = 8
• Ⅳ. 고찰 = 23
• Ⅴ. 결론 = 30
• Ⅵ. 참고문헌 = 32
• Ⅶ. ABSTRACT = 39