Christensen T, Volden G, Moan J, Sandquist T
Ann Clin Res. 1982 Feb;14(1):46-52.
NHIK 3025 cells in monolayer cultures were irradiated with near ultraviolet light in the presence of hematoporphyrin derivative (HPD). The release of lysosomal enzymes and the cytosol marker enzyme lactate dehydrogenase to the culture medium was determined 1, 3, 6 and 24 hours after irradiation. The enzyme activities of the cell pellet were investigated 24 hours after irradiating the cells. After exposure of HPD-labelled cells to light doses causing no cell inactivation, the leakage of enzymes was slightly inhibited in the first 6 hours followed by a period between 6 and 24 hours when the cells released the same amount or slightly more enzymes than the control. The enzyme activities of cell pellets made 24 hours after exposure were 40-75% of control values due to either a small inhibition of cellular enzyme activity or of inhibited cell growth by this dose. A higher light dose inactivating 80-90% of the cells, caused a rapid release of both lysosomal and cytosol enzymes. The cell pellets contained very little of the enzymes 24 hours after treatment and especially free intracellular enzymes had been released with high efficiency. Leupeptin, a lysosomal protease inhibitor, did not protect the cells from inactivation. We conclude that the release of lysosomal enzymes after porphyrins and light is of little significance in terms of cell killing.
将单层培养的NHIK 3025细胞在血卟啉衍生物（HPD）存在的情况下用近紫外光照射。在照射后1、3、6和24小时测定溶酶体酶和胞质溶胶标记酶乳酸脱氢酶向培养基中的释放情况。在照射细胞24小时后研究细胞沉淀的酶活性。在用不导致细胞失活的光剂量照射HPD标记的细胞后，酶的泄漏在前6小时略有抑制，随后在6至24小时期间，细胞释放的酶量与对照相同或略多。由于该剂量对细胞酶活性的轻微抑制或细胞生长的抑制，照射24小时后制备的细胞沉淀的酶活性为对照值的40 - 75%。使80 - 90%的细胞失活的较高光剂量导致溶酶体酶和胞质溶胶酶迅速释放。处理24小时后，细胞沉淀中几乎不含这些酶，尤其是细胞内游离酶已被高效释放。溶酶体蛋白酶抑制剂亮肽素不能保护细胞免于失活。我们得出结论，卟啉和光照后溶酶体酶的释放对细胞杀伤而言意义不大。
