Stability and reaction of the dithiocarbamate-ferrous-NO complex in PMA-stimulated peritoneal macrophages

摘要

In this study the stability of the NO spin-trapping complex, (dithiocarbamate)_2Fe~(2+) NO and its interaction with rat peritoneal macrophages was investigated. The stability experiments showed that DTCS (dithiocarboxy sarcosine) trapping complex was more stable than that of MGD (N-methyl-D-glucamine-dithiocarbamate) in macrophages activated by PMA (phorbol-1,2-myristate-1,3-acetate) and L-arginine. Free radical species, O_2~(·-) and NO, generated in macrophages respiratory burst were causative for the instability of the NO trapping complex. Addition of more dithiocarbamate and ferrous salt could increase the stability of the trapping complex in the system. Dithiocarbamate and ferrous salt did not impair the oxygen consumption of macrophages. The increasing effects of dithiocarbamate derivatives and ferrous salt on the stability of the trapping complex may be due to their scavenging effects on the free radicals generated by macrophages and their ability to inhibit the oxidation of ferrous ion in the (dithiocarbamate)_2Fe~(2+)NO complex.