In vivo inhibition of inducible nitric oxide synthase by aminoguanidine influences free radicals production and macrophage activity in Trichinella spiralis infected low responders (C57BL/6) and high responders (BALB/c) mice

The influence of aminoguanidine (AG) — inhibitor of inducible nitric oxide synthase (iNOS), on macrophage activity and free radicals level was examined during Trichinella spiralis infection in two strains of mice: C57BL/6 and BALB/c. AG was administered either between 1–5 days post infection (dpi) for intestinal phase examinations or between 16–29 dpi for muscle phase examinations. The number of peritoneal macrophages and level of nitric oxide NO) and hydrogen peroxide (H2O2) in biological fluids were determined in both strains after infection or infection together with AG treatment as well as in control uninfected mice. The performed studies have proved, that free radicals play role in host immune response during intestinal and muscle phase of T.spiralis infection in mice. Inflammatory response in peritoneal cavity was delayed during infection in low responders C57BL/6 mice in comparison with high responders BALB/c mice. C57BL/6 mice are Th-1 like strain and react stronger to AG in contrary to BALB/c being Th-2 like strain. It was manifested as changes and fluctuations of free radicals levels and in the number of peritoneal macrophages after AG treatment in C57BL/6 mice. A weak or no reaction on AG injection in BALB/c mice is responsible for more stable and more effective defense response of the host to T. spiralis infection.