抄録
Ethyl p-hydroxybenzoate (EPH) is one of preservatives (parabens). Medaka (Oryzias latipes), about 1 year old in age, were exposed to aqueous solution of EPH at concentration of 5 ppm for 30 weeks. Histopathological examination revealed induction of vitellogenesis in either sex after 6 weeks and development of testis-ova in 3 males at the 30 weeks. These attentions are the estrogen-like activity. In addition, in female after 30 weeks, ovary-spermia was observed in ovary. This attention is the androgen-like activity. These results suggested that EPH is an endocrine disruptor on androgenesis as well as estrogenesis.
