Macrosialin may not be involved with the regulation of nitric oxide production from mouse peritoneal macrophages stimulated with LPS

We reported previously that nitric oxide (NO) production from mouse periton eal macrophages stimulated with LPS was inhibited by negatively charged lip osomes composed of phosphatidylserine (PS-liposomes) or oxidized LDL (Ox-LD L) which have an affinity for scavenger receptors (SRs). In this study, to clarify whether macrosialin, an SR, participates in the inhibitory effects of PS-liposomes or Ox-LDL on NO production, the effects of anti-macrosialin monoclonal antibody (FA/11) on inhibition of NO production by PS-liposomes or Ox-LDL were investigated. FA/11 itself showed no effect on NO productio n induced by LPS. Binding of FA/11 to macrophages was inhibited by the addi tion of PS-liposomes or Ox-LDL, indicating that PS-liposomes or Ox-LDL have an affinity for macrosialin. However, the inhibitory effects of these liga nds on NO production were not reduced in the presence of FA/11. These findi ngs suggest that macrosialin does not contribute to the inhibitory effects of PS-liposomes or Ox-LDL on NO production hom mouse peritoneal macrophages stimulated with LPS.