Abstract
A number of chemical compounds have physiological effects indicating they possess estrogenic activity. These xenobiotic estrogens can have harmful effects on wildlife and human health by disrupting reproductive and developmental processes. Recently it was reported that caged male rainbow trout placed in the effluent of sewage-treatment works, were induced to synthesize vitellogenin. Vitellogenin is a protein that specifically appears in blood of sexually maturing female oviparous animals. Vitellogenin is a glycolipophosphoprotein that is produced by the liver in response to circulating estrogen, released into the blood stream, taken up by the developing oocytes, and chemically modified in the process of yolk formation. Vitellogenin is normally found only in the blood of adult females, but it can be induced in males and immature females by estrogen. The presence of vitellogenin in the blood of male fish can be used as a biomarker for estrogenic contamination of the aquatic environment.
