Histomorphological Evaluation of Pimephales promelas Male Gonads after Exposure to Pulp Mill and Domestic Discharges into the Uruguay River (Fray Bentos-Uruguay)

摘要

Fish are subject to a broad variety of stressorsbecause their homeostatic mechanisms are highlydependent on prevailing conditions in their immediatelysurroundings [1]. Moreover, they are suitable models forevaluating endocrine-active compounds in the watercolumn. Fathead minnow (Pimephales promelas) Pisces:Cypriniforms has been used as a sentinel organism forecotoxicity since the sixties for USEPA, EnvironmentCanada and OECD. An increased number of widely usedurban, industrial and agricultural chemicals are beingfound to cause endocrine disruption. In fishes,xenoestrogens can induce female proteins in males, andin some cases, the development of testis-ova [2].Histomorphological alterations of the testis in Fatheadminnow have been previously described for 17遝stradiol[3, 4], 4-nonylphenol and nonylphenolethoxylate [5]. We studied here the potential estrogeniceffect of pulp mill and domestic wastewater dischargeslocated on the Uruguay River on the male gonads of theFathead minnow, and we compared it to the effect oftreatment with 17?estradiol (E2).