engleski

Subcellular changes in uterus under atrazine influence

Oestrogenic hormones play a key role in regulating development, growth, proliferation and differential function in the mammalian uterus. Pesticides have been found to affect the mammalian reproductive processes by inducing changes in the neuroendocrine organs and target tissues. Atrazine (2-chloro-4-ethylamino-6-isopropylamino-s-triazine)which influenced the formation of a specific oestradiol-receptor complex (ORC) in the rat uterus cytosol has been examined in vitro and in vivo. In vitro atrazine (0.242 to 0.696 micromol) or in vivo (treatment per os 3 to 12 mg/kg b.w. daily/7 days) significantly (P<0.001) inhibited the formation of ORC in the rat uterus cytosol for 31 to 40%. The decrease in the number of free specific binding sites on the receptors was determined by using labelled oestradiol and Scatchard. The affinity of binding was not modified under the influence of herbicide, and the K_d value was of the same order of magnitude (10^-9 M). The inhibition was found to be fully non-competitive. Primary monolayer cell culture from the mature rat uterus in the presence of 0.03 to 0.18 micromol atrazine has shown the highest inhibition of the cell growth from proestrous (41 to 54%), than oestrus (25 to 48%) and dioestrous (32 to 45%) phase. In vivo treatment with atrazine has also shown histochemical changes on cell proliferation and immunohistichemical changes with MAb detection for oestrogen receptors. This study present findings in toxicological changes at rat uterus level, which is one of the most widely used experimental systems for studying the oestrogenic regulation of uterine growth and function.

atrazine; rat; uterus; oestradiol; receptor; cell culture

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