E. Baatrup et M. Junge, Antiandrogenic pesticides disrupt sexual characteristics in the adult maleguppy (Poecilia reticulata), ENVIR H PER, 109(10), 2001, pp. 1063-1070
Environmental contaminants have been identified as endocrine disruptors thr
ough their antiandrogenic activity. Thus, as androgen receptor antagonists,
the fungicide vinclozolin and the principal DDT metabolite p,p ' -DDE have
been demonstrated to induce demasculinization in rats. Whether this is als
o the case in fish remains to be demonstrated. For a period of 30 days, gro
ups of adult male guppies were exposed to vinclozolin, p,p ' -DDE, or the t
herapeutic antiandrogen flutamide (used as positive control) applied to the
fodder at concentrations between 0.1 and 100 mug/g fodder. Subsequently, s
exual characteristics of relevance to the male reproductive capacity were m
easured and compared with untreated control fish. All three chemicals cause
d profound alterations at increasing levels of biological organization, eve
n in these fully matured males. At the cellular level, the three compounds
induced a significant reduction in the number of ejaculated sperm cells. At
the organ level, the sexually attractive orange-yellow coloration was redu
ced in area and discolored, and treated fish also had smaller testes. Furth
er, at the organismal level, computer-aided behavior analyses demonstrated
a severe disruption in male courtship behavior. We conclude that this demas
culinization is consistent with an antiandrogenic action of vinclozolin and
p,p ' -DDE and is likely to compromise reproductive capability in this fis
h.