Postnatal exposure to endosulfan in postnatal exposure to endosulfan interferes with the normal development of the male rat mammary gland.

GABRIELA A. ALTAMIRANO, ; AYELÉN L. GOMEZ,; EDUARDO D. MASAT, ; VERÓNICA L. BOSQUIAZZO, ; ENRIQUE H. LUQUE, ; GABRIELA ALTAMIRANO, ENRIQUE LUQUE, MÓNICA MUÑOZ-DE-TORO, LAURA KASS.; MELISA B. DELCONTE,; RAMIRO ALARCÓN, ; MÓNICA M. MUÑOZ-DE-TORO,

Otro; LXI Reunión Científica Anual de la Sociedad Argentina de Investigación Clinica.; 2016

Endosulfan is one of the organochlorine pesticides that canact as an estrogen agonist and, it has been shoYn that stimulatesthe proliferation of the human mammary tumor cell line/CF in vitro. The male rat mammary gland /) is sensitiveto endocrine disruptors and, in the present study, our aim Yas toevaluate Yhether postnatal exposure to endosulfan modifies /)development in pre and postpubertal male rats. From postnatalday 20& to20&, male animals Yere injected subcutaneouslyevery h Yith a corn oil vehicle, control or b zg/Mg body Yeight of endosulfan. 1n 20& and 20&, blood and/) samples Yere collected. /) Yere processed for Yhole mount9/ or paraffin embedded. Testosterone T serum levels, /)histomorphology, collagen fibers organization, proliferation index,and the expression of estrogen ES4 and androgen receptorA4 Yere evaluated. 1n 20&, /) area, perimeter, longitudinalgroYth and number of terminal end buds TE$s Yere higher inendosulfanexposed than in control rats. Changes in histologicalsections such as alveolar development and increased presenceof organized collagen in the stroma parallel those observed in the9/. Also, epithelial ES4 expression Yas higher in endosulfanexposed .v. than in control rats .v., p.. 1n20&, an increased longitudinal groYth and number of terminalstructures Yere correlated Yith a higher proliferation index inendosulfanexposed .v. than in control animals .v.p.. /ore developed lobuloalveolar structures in addition tohyperplastic ducts surrounded by dense stroma, rich in collagenfibers, Yere observed in endosulfantreated rats. 1n the otherhand, T levels and A4 expression Yere similar betYeen groups.+n conclusion, our results shoY that the exposure to endosulfan inthe first YeeM of life interferes Yith the normal development of theMG and induces pre-malignant lesions in postpubertal male rats.