Investigation of immunotoxicity of supercypermethrin forte in the Wistar rat.

The study was done to find out whether subacute exposure to supercypermethrin forte (SCM) affected cellular and humoral immunity. Groups of 10 male Wistar rats were given SCM by gavage for 28 days at 12.5 mg kg-1 day-1 (1/14 LD50), 8.75 mg kg-1 day-1 (1/20 LD50) and 4.38 mg kg-1 day-1 (1/40 LD50) and the response of splenocytes to mitogens, natural killer cell activity, plaque forming cell assay and phagocytosis were examined. The response of splenocytes to the mitogens phytohaemagglutin and concanavalin A, and to a T-dependent antigen (sheep red blood cells), was enhanced at 1/40 LD50 SCM, and at 1/20 and 1/14 LD50 these variables were suppressed. In the group exposed to 1/14 LD40 SCM the suppression was statistically significant. A non significant but dose-related increase in NK-cell activity was observed. The phagocytic activity of polymorphes was not significantly affected. Thus, SCM at 1/14 LD50 had significant adverse effects on a number of immunological functions in rats, but lower doses had no effect on these activities.