Oestrogenic activity of an environmentally persistent alkylphenol in the reproductive tract but not the brain of rodents.

Compounds with oestrogenic actions present in the environment as a result of human activity may represent a threat to health and reproductive efficiency in human and wildlife populations. We show here that parenteral administration of octylphenol, a recently described environmental oestrogen derived from one group of non-ionic surfactants, is active in stimulating oestrogen-dependent uterine growth in prepubertal rats, but has no influence on perinatal sexual differentiation of the rat brain. These results extend previous in vitro findings to show that alkylphenols exert weak oestrogenic activity in vivo in mammals.