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IN-VITRO METHODS FOR EVALUATING SIDE EFFECTS OF PESTICIDES AND TOXIC SUBSTANCES
Citation:
Narahashi, T. IN-VITRO METHODS FOR EVALUATING SIDE EFFECTS OF PESTICIDES AND TOXIC SUBSTANCES. U.S. Environmental Protection Agency, Washington, D.C., EPA/600/1-76/035 (NTIS PB260385), 1976.
Description:
Several skeletal muscle and smooth muscle preparations have been examined for their usefulness in evaluating the toxic effects of a variety of insecticides. The following preparations were found satisfactory for such test: guinea pig ileum for muscarinic receptors, guinea pig heart for beta-adrenergic receptors, guinea pig vas deferens for alpha-adrenergic receptors, frog rectus abdominis for nicotinic receptors of tonic muscle, and rat diaphragm for nicotinic receptors of phase muscle. Five carbamate insecticides, four organophosphate insecticides and chlordimeform were studied. None of the insecticides tested had any direct and potent effect on these receptors except the effect on cholinergic receptors via cholinesterase inhibition. Carbofuran, propoxur and formetanate had potent stimulating actions on the guinea pig ileum, but these effects could entirely be attributed to the accumulation of acetylcholine in the synaptic cleft as a result of cholinesterase inhibition. Thus, it can be concluded that these insecticides exert no direct action on cholinergic and adrenergic receptors.