摘要：Nitrogen oxide, which is produced by activated macrophages, has been demonstrated to possess anti-tumor activity. We report herein the synergistic effect of sodium nitrite (NO-2) and/or sodium nitroprusside (SNP) on lysophospholipid (LysoPL)-mediated cytolysis. The incubation of 51Cr-labeled mouse melanoma (B16) cells with NO-2 alone for 3 h at 37°C did not induce cytolysis. On the other hand, NO-2 significantly enhanced the cytolysis of B16 cells in the presence of lysophosphatidylcholine (LysoPC; 2.0 μM). A similar effect of NO-2 on B16-cytolysis was also observed in the presence of 1-O-alkyl-sn-glycero-3-phosphocholine (LysoPAF). In addition, SNP (0.05-0.5 mM) synergistically enhanced B16-cytolysis in the presence of LysoPC. However, nitrate had no effect on the cytolysis of B16 cells treated with LysoPC. Furthermore, NO-2 synergistically enhanced the hemolysis of sheep erythrocytes in the presence of LysoPC, but not in the presence of an anti-sheep erythrocyte antibody and complement. These findings suggest that NO-2 directly affects membrane damage in the presence of LysoPL.
