臨牀透析 Vol.16 No.14(1)


特集名 今日のCAPD療法
題名 腹膜の解剖と生理
発刊年月 2000年 12月
著者 濱田 千江子 順天堂大学医学部腎臓内科
【 要旨 】 腹膜は,壁側腹膜と臓側腹膜からなる.腹膜は腹腔から1層の中皮細胞層と,粗な間質からなり,間質には毛細血管やリンパ管を含む.中皮細胞はおもに分泌細胞,免疫防御機能に関わる.中皮細胞の絨毛は,腹腔臓器保護や細胞と腹腔内成分の交換を促進する役割がある.毛細血管は腹膜の透析機能を支え,三つに分けられる.血管内皮細胞には,物質移送に関与すると思われる飲小胞が細胞全体に多数存在している.腹腔内はリンパ管網となっており,横隔膜下のstomataで溶質や蛋白,血球の環流が行われている.腹腔内には,免疫機能を支えるマクロファージや組織球などが存在し,サイトカインネットワークを形成している.腹腔での透析液の分布は不均一であり,肝および脾周囲は排液不良部位や腹膜炎時の膿瘍好発部位となる.腹膜での物質移送のルートは,(1) おもに小分子物質移送に関与するsmall pores,(2) 中・大分子物質の移送に関与するlarge pores,(3) 経毛細管の限外濾過に関与するultrasmall poresの三つがある.体液の移動は,限外濾過と腹腔内液の喪失からなり,限外濾過は血管と腹腔間の静水圧や膠質浸透圧,晶質浸透圧の格差に規定される.腹腔内液喪失はリンパ管吸収と逆浸透の和である.
Theme CAPD Up-to-date 2000
Title The anatomy and physiology of peritoneum
Author Chieko Hamada Division of Nephrology, Department of Medicine, Juntendo University
[ Summary ] The structure of the peritoneum may be the parietal peritoneum and the visceral peritoneum. The peritoneal serous membrane consists of a monolayer of flat cells on a basement membrane, and a layer of loose connective tissue, blood vessels and lymphatic vessels. The mesothelium is an important layer for the prevention of inflammation and the secretion of substances. The mesothelial microvilli have the function of protecting abdominal organs and facilitating exchanges between cells and the peritoneal fluid. Connective tissue contains many blood vessels that mainly play a function in solute transport and ultrafiltration. There is an enormous abundance of pinocytotic vesicles, which along with the macromolecules play a role in transportation within endothelial cells. There is a complex network of lymphatics in the peritoneum. Stomata in the peritoneum , in proximity to the diaphragm, help in the drainage of solutes, protein and blood cells. There is a cytokine network composed of immune reacting cells : macrophages, mast cells, plasma cells, leukocytes and fibroblasts in the peritoneum. The distribution of peritoneal fluid is not uniform, some of the characteristics which demonstrate this are that the peritoneal cavity may experience an outbreak of bolus residual peritoneal fluid and abscesses around liver and/or spleen. Peritoneal solute transport is thought to take place through a three pore system, (1) the small pores : mainly related to the low molecule transport, (2) the large pores: involved in the transport of macromolecules, (3) the ultrasmall pores : supports transcellular water transport, named the water channel. Fluid transport consists of water transport from the peritoneal capillaries into the peritoneal cavity by trans capillary ultrafiltration and by fluid loss out of the peritoneal cavity. Hydrostatic factors include, the colloid osmotic and the crystalloid osmotic pressure gradients which exert an influence on transcapillary ultrafiltration. Fluid loss out of the peritoneal cavity is coupled to lymphatic absorption and back filtration by colloid osmosis.
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