An evaluation of the effect of 2,4-dichlorophenoxyacetic acid derivatives on humoral and cellular immunities

A single oral administration of phenoxy herbicides, viz. 2,4-dichlorophenoxyacetic acid (2,4-D), amino salt, sodium salt, diethylene glycol, iso-octyl and octyl ethers in a dose of LD16, was found to produce a pronounced suppressive effect on humoral immunity on day 5. The 2,4-D derivatives under study, administered in the same dose, stimulated the manifestations of delayed-type hypersensitivity in mice immunized with sheep red blood cells. The effect of the inhibition of antibody formation to thymus-dependent antigen ranged in the order of the increase in the toxicity of substances: amino salt, diethylene glycol ether, 2,4-D, sodium salt, iso-octyl and octyl ethers. On the contrary, the intensity of delayed-type hypersensitivity was more pronounced with regard to substances having greater toxicity.