Department of Pharmacology I.B. Universidade do Estado do Rio de Janeiro Ribeirão Preto 14049-900 Brazil.
Mediators Inflamm. 1995;4(3):222-8. doi: 10.1155/S0962935195000366.
Polymorphonuclear neutrophils (PMN) obtained from carrageenin-stimulated peritoneal cavities of rats, but not blood PMN, spontaneously produced nitric oxide (NO) when incubated in vitro. Incubation of the cells with the NO synthase inhibitors, L-imino-ethyl-L-ornithine (L-NIO) or N(G)-monomethyl-L-arginine (L-NMMA), inhibited NO production. This inhibition could be reversed by L-arginine. Incubation of PMN with lipopolysaccharide (LPS) failed to enhance NO production. Pretreatment of the rats with dexamethasone (DEXA) prior to carrageenin injection or incubation of PMN with the glucocorticoid in vitro partially inhibited the spontaneous release of NO. On the other hand, when PMN obtained from DEXA pretreated rats were incubated in vitro with DEXA, NO synthase activity and hence NO generation were almost abolished. A similar inhibition was also observed following the addition of L-NIO or cycloheximide to cultures of carrageenin-elicited PMN. The NO production by PMN did not appear to be related to cell viability or apoptosis. Indeed, neither the blockade of NO generation by L-NIO nor the incubation of the neutrophils with a NO donor, S-nitroso-acetylpenicillamine (SNAP) modified the pattern of LDH release or DNA fragmentation. In summary, it appears that PMN migration triggers a continuous NO synthesis, and that NO produced by these cells is not related to their apoptosis.
多形核白细胞（PMN）从大鼠的角叉菜胶刺激的腹腔中获得，但不是血液 PMN，当在体外孵育时会自发产生一氧化氮（NO）。将细胞与一氧化氮合酶抑制剂 L-亚氨基乙基-L-鸟氨酸（L-NIO）或 N（G）-单甲基-L-精氨酸（L-NMMA）孵育，可抑制 NO 的产生。这种抑制可以被 L-精氨酸逆转。将 LPS 孵育 PMN 未能增强 NO 的产生。在角叉菜胶注射前用地塞米松（DEXA）预处理大鼠或在体外用糖皮质激素孵育 PMN 可部分抑制自发释放的 NO。另一方面，当从 DEXA 预处理的大鼠中获得 PMN 并在体外与 DEXA 孵育时，NO 合酶活性和因此生成的 NO 几乎被完全抑制。在角叉菜胶诱导的 PMN 的培养物中加入 L-NIO 或环己亚胺也观察到类似的抑制。PMN 产生的 NO 似乎与细胞活力或凋亡无关。事实上，L-NIO 阻断 NO 生成的作用或用 NO 供体 S-亚硝基乙酰青霉胺（SNAP）孵育中性粒细胞均未改变 LDH 释放或 DNA 片段化的模式。总之，似乎 PMN 迁移触发了持续的 NO 合成，并且这些细胞产生的 NO 与其凋亡无关。
