Effect of 4-octylphenol on germ cell number in cultured human fetal gonads

This study evaluates whether a hormone disruptor found in environment, 4-octylphenol, affects the rate of proliferation of germ cells from human fetal gonads during a 3 week culture period. Five testis and five ovaries were obtained from fetuses of women undergoing legal abortions between the 6th and 9th week of fetal life, representing the period where early gonadal differentiation takes place. Each gonad was divided into equal sized test and control tissue. The test tissue was exposed to a continued presence of 10 micromol/l 4-octylphenol in the culture medium. The cultures were terminated by fixation of the tissues, which where then processed for histology and serially sectioned. The mitotic index of the germ cells (i.e. number of mitosis per 100 germ cells) and the number of germ cells per area was determined. Each of the five testes cultured in 4-octylphenol exhibited a significantly reduced mitotic index and number of pre-spermatogonia compared to the control, whereas none of the five ovaries exposed to 4-octylphenol revealed any difference compared to the control. It is concluded that 4-octylphenol exerts a sex-specific effect on male germ cells.