The influence of zinc in mice on infection with Angiostrongylus cantonensis.

BALB/cByJ mice were divided into zinc-deficient (ZD), high zinc-supplemented (ZH), adequately zinc-replete (ZA) and normal control groups by daily dietary control. The body weight in ZD and ZH mice became significantly less than that of normal control mice from 4 weeks (P < 0.002) until 7 weeks (P < 0.0001) after consecutive zinc control. The kinetics of change in body weight of ZD and ZH mice after infection with Angiostrongylus cantonensis were similar to that of uninfected groups mentioned above. The worms recovered at days 7, 14 and 21 after infection from ZD and ZH mice were significantly more in number than that in control mice (P < 0.01). However, the worms from day 21 after infection were shorter in size than those in control mice (P < 0.01). The production of interleukin (IL)-5 was significantly depressed in cultured spleen cells from uninfected and infected ZD and ZH mice, compared with that from respective control group (P < or = 0.02). Furthermore, significantly lower eosinophil counts were observed in the cerebral spinal fluid(CSF) of ZD and ZH mice 3 weeks after infection than in the CSF of control mice (P < 0.001). The levels of immunoglobulins IgG, IgM, IgA and IgE in the supernatant of cultivated spleen cells and serum from ZD and ZH mice were all lower than those of control mice. Thus, the level of zinc correlated with the defence against infection by A. cantonensis, due to the influence of zinc on the growth of mice and their production of IL-5, eosinophils and immunoglobulins.