Ultrastructural Studies on Molecular Sieve of Basement Membrane in Outer Blood-Retinal Barrier.

Research Project

Project/Area Number	60570835
Research Category	Grant-in-Aid for General Scientific Research (C)
Allocation Type	Single-year Grants
Research Field	Ophthalmology
Research Institution	Okayama University.
Principal Investigator	MATSUOKA Tohru Okayama University Medical School, 医学部附属病院, 講師 (10165780)
Co-Investigator(Kenkyū-buntansha)	SAKAGUCHI Noriko Okayama University Medical School, 医学部附属病院, 助手 (90170589) SHIRAGA Fumio Okayama University Medical School, 医学部附属病院, 助手 (50187530) KOYAMA Tetsurou Okayama University Medical School, 医学部附属病院, 講師 (50135993) 大野敦史岡山大学, 医学部附属病院, 助手田中利幸岡山大学, 医学部附属病院, 助手 (50171781)
Project Period (FY)	1985 – 1987
Project Status	Completed (Fiscal Year 1987)
Budget Amount *help	¥1,500,000 (Direct Cost: ¥1,500,000) Fiscal Year 1987: ¥300,000 (Direct Cost: ¥300,000) Fiscal Year 1986: ¥600,000 (Direct Cost: ¥600,000) Fiscal Year 1985: ¥600,000 (Direct Cost: ¥600,000)
Keywords	Basement Membrane / Blood-retinal barrier / Freeze-fracture / Deep-etching / Choriocapillary endothelium / Retinal pigment epithelium / 分子節 / 分子篩 / ブルック膜 / フリーズフラクチャー / ディープエッチング法
Research Abstract	Three-dimensional strucutr of basement membranes(BM) of choriocapillary endothelium and retinal pigment epithelium of monkeys and rabbits were studied by freeze-fracture deep-etching method. We saw connecting filaments 4-13 nm in diameter in the lamina lucida of the BM. They linked the plasma membrane of the endothelium with the lamina densa of the BM. Small pores, 6-17nm in diameter, could be observed in the lamina densa of the BM of the choriocapillary endothelium and the retinal pigment epithelium. The size of pores in the lamina densa of choriocapillary endothelium of the rabbit was relativery large compared with that of the monkey. The characteristic structure of the BM may play a molecular sieving role in the outer blood-retinal barrier. The lamina lucida of the BM presented various forms, depending on the location of eyeball. The length anddensity of the connecting filamnets were different in the BM of the choriocapillary endothelium, depending on the posterior pole or periphery of the eyeball or the fenestra of the endothelium. After perfusion with cationized ferritin, ferritin particles were distributed in large clusters on luminal side of the fenestral diaphragm. The fenestral diaphragm has the highest density of anionic site on the luminal plasma membrane of the endothelium. In the inner limiting membrane, small pores were also found. They formed a part of the vitreo-retinal barrier. The basic structure of the BM in the retinochoroid was identical at any site,but the mode of connecting filament of its lamina lucida and the size of the small pores in the lamina densa and adhesive structure with collagen fibril outside the BM presented characteristic architectures, depending on their individual locations.