부산대학교 도서관

The detection of nitric oxide (NO) release by human polymorphonuclear neutrophil leukocytes (PMNs) presents several difficulties, mainly due to concomitant production of O2- and H2O2, which could interfere with the measurements. A Nafion and nickel porphyrin-coated microelectrode was used to measure NO production in PMNs in vitro. It allowed detection of 6.3±1.9 nM NO in a PMN-containing system and was unaffected by added chemicals. Addition of the chemotactic oligopeptide f-met-leu-phe (fMLP; 100 nM) induced a NO release which reached a value of 71±30 pmol NO/106 PMN×ml[sup -1] 5 min after stimulation in the presence of SOD (150 U/ml). If SOD was omitted, the corresponding value was 36±20 pmol NO/106 PMN×ml-1. Presence or absence of catalase did not alter the amount of NO measured. Addition of the NO-synthase inhibitor NG-monomethyl-L-arginine (LNMMA; 1 mM) reduced the current by 82 ± 20%. These results agree with the rate of NO production in human PMNs when measured spectrophotometrically using the NO-dependent oxidation of oxyhaemoglobin to methaemoglobin. The NO production in human PMN was dependent on fMLP concentrations, but independent of cell-concentrations of 0.5-3.5×106/ml. This paper shows that a electrochemical method, e.g. Nafion and porphyrin-coated microelectrode, is suitable for studies of NO release from stimulated human PMNs. [ABSTRACT FROM AUTHOR]