视网膜色素上皮细胞对含甘露糖的HRP的吞噬作用

MANNOSE-SENSITIVE HRP ENDOCYTOSIS BY RETINAL PIGMENT EPITHELIUM CELLS

为探讨甘露糖受体在视网膜色素上皮细胞吞噬过程中的作用,用富含甘露糖的糖蛋白辣根过氧化酶(HRP)作为吞噬刺激物,D-甘露糖作为抑制剂,对48只Wistar大鼠眼球的视网膜色素上皮细胞在吞噬过程中其甘露糖受体的作用进行了研究,光密度计测定了视网膜色素上皮细胞内摄入HRP的含量,结果表明:HRP在一定浓度内,视网膜色素上皮细胞摄入HRP的含量与其浓度呈正相关;视网膜色素上皮细胞对一定浓度HRP的摄入在4小时内呈线性增加,在培养介质中加入10 mmol的D-甘露糖,视网膜色素上皮细胞对HRP的摄入量明显减少;1mmol的D-甘露糖对其抑制作用很小,100mmol的D-甘露糖对其抑制作用较大.以上结果提示,视网膜色素上皮细胞对HRP的摄入作用本要是山特异性甘露糖受体所介导.

To determine the role of mannose receptor during phagocytosis by retinal pigment epithelium cells (RPE), RPE explants of eye balls of 48 Wistar rats were used in this study. Mannose-rich glycoprotein horseradish peroxidase (HRP) was chosen as a ligand and D- mannbses as an inhibiting material. Enzyme assay was employed to determine the amount of HRP ingested by RPE cells. The results showed that amount of HP.P ingested by RPE cells was positively correlated to HRP concentration (HRP 6.25 - 100 μg/ml). There was a linear increase in the amount of HRPingested by RPE cells within 4 hours when HRP concentration was 50 ug/ml. The amount of HRP ingested by RPE cells decreased significantly when 10 mmol of D-mannose was added to the incubation medium, but there was little inhibition when 1 mmol of D-mannose was added. The results suggest that HRP ingestion by RPE cells is mainly mediated by a mannose - sensitive receptor.