A comparative study of porphyrin accumulation in tissue cultures of chicken embryo hepatocytes treated with organophosphorous pesticides.

Thirty-two organophosphorous pesticides have been examined for their ability to cause porphyrin accumulation in cultures of chicken embryo hepatocytes. Greatest porphyrin accumulation is associated with compounds which have an aromatic leaving group and are phosphate or thiono-phosphate ethyl esters. Compounds of this type cause accumulation of uroporphyrin in the medium. Paraoxon and diazoxon cause inhibition of uroporphyrinogen decarboxylase in the cells. The ability to cause accumulation of uroporphyrin in the medium does not correlate with the alkylating properties of the compound as measured by its rate of alkylation of 4-(p-nitrobenzyl)-pyridine.