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血小板来源的生长因子(platelet—derivedgrowthfactor,PDGF)是一种糖蛋白,分子量约30,000,它贮存在血小板的α颗粒中。对嗜中性白细胞、单核细胞、成纤维细胞和平滑肌细胞,PDGF 是一种强趋化因子。对成纤维细胞、平滑肌细胞、神经胶质细胞,它是一种强促细胞分裂剂。当血小板由于血液凝固激活并与损伤部位接触时,PDGF即释放出来,当此位置上同时可有嗜中性白细胞蛋白酶释放。本文检测了中性白细胞弹性蛋白酶,组织蛋白酶 G 和胰蛋白酶对 PDGF 的趋化性和致有丝分裂活性的影响。用人白细胞弹性蛋白酶、组织蛋白酶 G、胰蛋白酶水解 PDGF,用二硫苏糖醇和碘乙酰胺还原和烷化PDGF,再用单核细胞或胎牛韧带成纤维细胞(FCL)为靶细胞,用改良的 Boyden 小室法测定 PDGF 的趋化性。用依赖于 PDGF 的[~3H]-胸腺嘧啶核苷参入3T3细胞或 FCL DNA,测定 PDGF 的致有丝分裂活性。用~(125)I-PDGF 与3T3细胞或 FCL 的结合进行
Platelet-derived growth factor (PDGF) is a glycoprotein with a molecular weight of about 30,000 that is stored in alpha particles of platelets. For neutrophils, monocytes, fibroblasts and smooth muscle cells, PDGF is a potent chemotactic factor. It is a potent mitogen for fibroblasts, smooth muscle cells, and glial cells. When platelets are activated by blood clotting and come into contact with the damaged area, PDGF is released and neutrophil protease release occurs at the same time. This article examined the effects of neutrophil elastase, cathepsin G and trypsin on chemotactic and mitogenic activity of PDGF. PDGF was hydrolyzed with human leukocyte elastase, cathepsin G and trypsin, PDGF was reduced and alkylated with dithiothreitol and iodoacetamide, then monocytes or fetal calf ligament fibroblasts (FCL) were used as target cells, The Boyden chamber method was used to determine the chemotaxis of PDGF. The mitogenic activity of PDGF was assayed by incorporation of [~ 3H] -thymidine nucleotides dependent on PDGF into 3T3 cells or FCL DNA. Binding of ~ (125) I-PDGF to 3T3 cells or FCLs was performed