Organophosphorus and methyl carbamate insecticide teratogenesis: diminished NAD in chicken embryos.

Studies with 36 organophosphorus and 12 methyl carbamate compounds establish a correlation between reduction in nicotinamide adenine dinucleotide (NAD) levels and severity of teratogenic signs in chicken embryos, a relation supported by reversal of these effects by nicotinamide derivatives. Diminished NAD occurring at organophosphorus and methyl carbamate concentrations as low as 0.6 to 2.0 parts per million in the egg constitutes a newly recognized biochemical lesion induced by the two most important classes of insecticide chemicals.