Toxicological and Pharmacological Actions of Methacrylate Monomers II: Effects on Isolated Guinea Pig Ileum

Abstract

Methacrylic acid and 12 methacrylate esters were tested for their effects upon contraction of the isolated guinea pig ileum. Each compound was employed at three concentration levels, ranging from 1:500 to 1:100,000 (v/v), depending upon activity and solubility of the compounds. Most of the compounds, except dimethylaminoethyl methacrylate, produced an inhibition of spontaneous contractions of the isolated ileum which antagonized the stimulant actions of both acetylcholine and barium chloride. Although most of the methacrylate effects were readily washed out, 1,3-butylene dimethacrylate produced a relatively irreversible response. Dimethylaminoethyl methacrylate stimulated the isolated ileum, an effect that was not blocked by 0.1-1 mcg. of atropine/ml. of tissue bath fluid. Those compounds producing inhibition were ranked in order of their relative activities in antagonizing acetylcholine- or barium-induced contraction by determining the approximate molar ratio (i.e., molar concentration of methacrylate per molar concentration of acetylcholine or barium chloride) required to produce 50% inhibition of the stimulant effect of acetylcholine or barium chloride.