This study evaluates whether a hormone disrupter found in environment, 4-oc
tylphenol, affects the rate of proliferation of germ cells from human fetal
gonads during a 3 week culture period. Five testis and five ovaries were o
btained from fetuses of women undergoing legal abortions between the 6th an
d 9th week of fetal life, representing the period where early gonadal diffe
rentiation takes place. Each gonad was divided into equal sized test and co
ntrol tissue. The test tissue was exposed to a continued presence of 10 mu
mol/l 4-octylphenol in the culture medium. The cultures were terminated by
fixation of the tissues, which where then processed for histology and seria
lly 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. E
ach of the five testes cultured in 4-octylphenol exhibited a significantly
reduced mitotic index and number of pre-spermatogonia compared to the contr
ol, whereas none of the five ovaries exposed to 4-octylphenol revealed any
difference compared to the control. It is concluded that 4-octylphenol exer
ts a sex-specific effect on male germ cells.