Plasminogen inhibits complement-mediated hemolysis only when artificially activated and present at disproportionately high concentration.

A: Inhibition of erythrocyte lysis in highly diluted (1.5%) serum with increasing concentrations of added plasmin. Data for plasminogen, urokinase (used in preparation of plasmin), and the negative control BSA are also shown. The assay was done six times. B: Loss of plasmin-mediated inhibition of sheep erythrocytes (Es) with increasing concentration of serum. The concentration of plasmin was kept at 20% of the physiological plasma level. The assay was done six times. C: In addition to plasmin, hemolysis was inhibited with the proteases α-chymotrypsin and trypsin. The assay was done three times in triplicate. (Data shown are mean values ± SD. *, P

A：在1.5%高稀释血清体系中，随着添加的纤溶酶浓度升高，红细胞裂解受到显著抑制。同时展示了纤溶酶原、制备纤溶酶所用的尿激酶以及阴性对照牛血清白蛋白（Bovine Serum Albumin, BSA）的相关实验数据，该实验重复开展6次。
B：随着血清浓度升高，纤溶酶介导的绵羊红细胞（Es）裂解抑制效应逐渐减弱。实验中纤溶酶浓度维持在生理血浆水平的20%，该实验重复开展6次。
C：除纤溶酶外，α-胰凝乳蛋白酶与胰蛋白酶这两种蛋白酶也可抑制溶血反应。本实验采用三重平行重复设计，共完成3次独立实验。（展示的数据为平均值±标准差（Standard Deviation, SD），*表示P