Effects of 2,4 - Dichlorophenoxyacetic Acid on Experimental Animals.

Abstract

Parenteral admn. of 2,4-dichlorophenoxyacetic acid produced myotonia lasting from 8-24 hrs. or more following a single injn. of 150-200 mg./kg. in mice, rats, rabbits, and dogs. The approx. LD50, as detd. in mice by subcut. injn. was 280 mg./kg. Repeated injn. of smaller amts. (50-100 mg./kg.) to mice failed to elicit either a characteristic chronic syndrome or a striking histologic picture. Mice so treated became pregnant and bore apparently normal litters. The growth rate of young mice was slightly retarded, probably due to reduced food intake. The drug did not alter the rate of growth of 2 transplantable mouse sarcomas (Sarcoma 37 and Sarcoma 180).