Phagocytosis of erythrocytes by the proximal tubule of the rat kidney.
Phagocytosis of erythrocytes by the proximal tubule of the rat kidney.
复制标题
大鼠肾近曲小管对红细胞的吞噬作用。
DOI：
10.1007/bf00218366
复制
发表时间：
1982
影响因子：
3.6
通讯作者：
Tisher,CC
中科院分区：
文献类型：
--
作者：
Madsen,KM;Applegate,CW;Tisher,CC
肾小球肾炎和血尿患者肾活检的形态学检查显示近端小管上皮细胞内存在红细胞。这一观察结果表明，近端小管可能能够吞噬形态完整的红细胞。为了检查这种可能性，使用标准的显微穿刺技术将少量肝素化自体血液注射到大鼠肾脏近端小管的表面曲中。在注射后10 min至120 h的时间间隔内，通过用半强度Karnovsky戊二醛-甲醛固定剂滴注固定，保存肾脏用于光镜和透射电子显微镜检查。在最初的6 h期间，刷状缘变平，代表血红蛋白的电子致密物质积聚在顶端空泡和溶酶体样结构中。从6至15小时后，微穿刺，有进行性损失的刷状缘和伪足样外翻，延伸从顶端质膜和包围个别红细胞的同时形成。到18和24小时，在近端小管细胞中观察到红细胞。在较晚的时间间隔，观察到水肿，淋巴细胞浸润和纤维化的结节。此外，晶体结构存在于近端和远端小管的管腔和细胞中。这些发现表明，除了它们公认的吞吸血红蛋白和其他蛋白质的能力之外，近端小管的细胞能够吞吸形态完整的自体红细胞。近曲小管细胞的吞噬作用可能在血尿条件下从肾小管液中处置红细胞中发挥作用。
Morphological examination of kidney biopsies from patients with glomerulonephritis and hematuria has revealed the presence of erythrocytes within epithelial cells of the proximal tubule. This observation suggested that the proximal tubule might be capable of phagocytizing morphologically intact erythrocytes. To examine this possibility small quantities of heparinized autologous blood were injected into surface convolutions of proximal tubules of the rat kidney using standard micropuncture techniques. At time intervals ranging from 10 min to 120 h after injection, the kidneys were preserved for light and transmission electron microscopy by drip-fixation with a half-strength Karnovsky's glutaraldehyde-formaldehyde fixative.During the initial 6 h there was a flattening of the brush border and accumulation of electron-dense material representing hemoglobin in apical vacuoles and in lysosome-like structures. From 6 to 15 h after micropuncture, there was progressive loss of the brush border and the simultaneous formation of pseudopodia-like evaginations that extended from the apical plasma membrane and surrounded the individual erythrocytes. By 18 and 24 h, erythrocytes were observed in the proximal tubule cells. At later time intervals, edema, lymphocytic infiltration, and fibrosis were observed in the interstitium. In addition, crystalline structures were present in the lumen and the cells of both proximal and distal tubules. These findings suggest that in addition to their well-established ability to pinocytize hemoglobin and other proteins, the cells of the proximal tubule are capable of phagocytizing morphologically intact autologous erythrocytes. It is possible that phagocytosis by the proximal tubule cells may play a role in the disposal of erythrocytes from the tubular fluid in hematuric conditions.