Abstract

The effect of zirconium (Zr) on the humoral immune response was studied by measuring the level of IgM-plaque forming cells (IgM-PFC) against sheep red blood cells (SRBC) in the spleen of C57 BL mice intraperitoneally injected with zirconium oxychloride. Two experiments, a single injection of zirconium oxychloride of 1/5, 1/10, 1/50, and 1/100 of the LD50 for intraperitoneal injection and continuous injection of 1/20, 1/40, and 1/80 of the LD50 every other day for two or four weeks in mice, were carried out. In the case of a single injection zirconium oxychloride was intraperitoneally injected on days -1, 0, +1, +2, and +3 in relation to SRBC immunisation. The following conclusions may be drawn from this study: (1) Zr was shown to have an adjuvant like activity in relation to the humoral immune response, at least to IgM antibody production; (2) this effect was recognised not only with a single injection with Zr but also after continuous injection; (3) a single injection of Zr was more effective when the mice were treated with Zr 24 hours before or after SRBC immunisation; and (4) with regard to an injected dose of Zr, it was shown that a lower dose (1/50, 1/100 of the LD50 for a single injection and 1/40, 1/80 of the LD50 for continuous injection) led to a more enhanced level of IgM-PFC than a higher dose (1/5, 1/10 of the LD50 for a single injection, and 1/20 of the LD50 for continuous injection).