Immunotoxic Effects of MPT-IP Containing 60% Methylparathion in Mice

Abstract

The effects of a single large and repeated small doses of MPT-IP (the industrial product used to produce Wofatox EC 50) containing 60% methylparathion, on the humoral and cellular immunoreactivity of CFLP mice were investigated.

Administration of a single LD₅₀/2 dose 3 d prior to immunization caused a 40% increase in the number of splenic PFC on the 5th day but no significant increase in serum antibody titre on the 7th day after immunization.

Treatment for 4 weeks with an LD₅₀/40 dose resulted in a 100% increase in splenic PFC, also not associated with a change in serum antibody titre. Under the same conditions and LD₅₀/20 dose had no effect on these parameters.

Neither the single large nor the repeated small doses had any effect on the intensity or time course of a DTH reaction.

The results show that MPT-IP has an immunotoxic potential in mice under certain experimental conditions.