Effect of heavy metal intoxication on macrophage metabolic activity of mice infected with Ascaris suum

The effect of heavy metal intoxication on superoxide anion (O2 −) production and larval burden during experimental Ascaris suum infection was studied. Mice were chronically intoxicated with lead (Pb), cadmium (Cd) or mercury (Hg) and subsequently infected with A. suum. The metabolic activity of peritoneal macrophages in mice intoxicated with Pb was suppressed and subsequent parasitic infection did not change this inhibition. Cd intoxication increased the superoxide production and also stimulated the activity of this oxygen radical after A. suum infection. Intoxication with Hg had a stimulative effect on the macrophage metabolic activity and subsequent A. suum infection moderately reduced this activity. Parasite burden was different depending on a type of heavy metal intoxication. Pb intoxication moderately increased the parasite burden in the liver and lungs of intoxicated mice. In contrast, Cd and Hg intoxication triggered a marked reduction of A. suum larvae in the liver and lungs of intoxicated mice, respectively. Monitored heavy metals differed in their immunomodulatory effect on metabolic activity of macrophages what also altered the intensity of the parasite infection in the hosts.