Effect of parathion and methylparathion on protein content of chicken embryo muscle in vivo.

Chicken eggs were treated with 0.4 per cent solutions of parathion or methylparathion for four or eight days, and the two-dimensional gel electrophoretic protein pattern of cervical muscles of eighteen days old embryos was analyzed. Both compounds significantly decreased the content of alpha-actinin, alpha-tubulin and beta-tubulin after four days treatment, and, in addition, that of three other related proteins (gamma-proteins) after eight days treatment. Under in vitro phosphorylating conditions, both methylparathion and parathion specifically inhibited the phosphorylation of one isoform of beta-tubulin. Data suggest that the muscle-damaging effects of organophosphorous insecticides, such as parathion and its derivates, may be related to the decrease of tissue content of certain cytoskeletal proteins.