Action of some pesticides on T4 to T3 conversion in cultured kidney and liver cells in the presence or absence of cysteine.

: The influence of aminotriazole (ATA), atrazine (ATZ), prometryne (P) and ATC on T4 to T3 conversion in kidney and liver cell cultures in the presence or absence of cysteine was studied. The experiment was carried out on cell cultures (rat renal cells and human embryo cells) and organotypic cultures (rat liver cells), treated with the above mentioned pesticides in 2 doses each, in the presence of 1 microgram and 10 micrograms T4 in the culture medium. This experiment was reproduced in the same conditions supplementing the culture medium with 30 mg cysteine per 100 ml culture medium. T3 and T4 in the culture medium were measured by RIA. The proteins in the monolayer cultures were also assayed. Cysteine proved to stimulate T4 to T3 conversion at the level of human and rat kidney cells with little variation depending on the pesticide and the dose applied. Between the activities of the human and the rat cells in the presence of the same pesticide, there were clear differences. The latter are also expressed in the values of proteic synthesis taking place in the renal human embryo cells and rat renal cell cultures under the same influences.