Regulation of prostaglandin E2 production by the superoxide radical and nitric oxide in mouse peritoneal macrophages.

The purpose of this study was to elucidate the role of NO and O2 on enzymatic components of cyclooxygenase (COX) pathway in peritoneal macrophages. Activation of murine peritoneal macrophages by lipopolysaccharides (LPS) resulted in time-dependent production of nitric oxide (NO) and prostaglandin E2 (PGE2). This stimulation was also accompanied by the production of other reactive oxygen species such as superoxide (O2-), and by increased expression of COX-2. Our results provide evidence that O2- may be involved in the pathways that result in arachidonate release and PGE2 formation by COX-2 in murine peritoneal macrophages stimulated by LPS. However, we were not able to demonstrate that NO participates in the regulation of PG production under our experimental conditions.