Early postnatal exposure to endosulfan interferes with the normal development of the male rat mammary gland

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

TOXICOLOGY LETTERS

ELSEVIER IRELAND LTD

Año: 2017 vol. 281 p. 102 - 109

0378-4274

Our aim was to evaluate whether postnatal exposure toendosulfan (ENDO) modifies mammary gland (MG) development in pre- andpost-pubertal male rats. From postnatal day 1 (PND1) to PND7, male rats wereinjected subcutaneously every 48 h with either corn oil (vehicle) or 600 μg ENDO/kg.bw. On PND21 and PND60, MG and blood sampleswere collected. Estradiol (E2) and testosterone (T) serum levels, MG histology,collagen fiber organization, proliferation index, and estrogen (ESR1) andandrogen receptor (AR) expressions were evaluated. On PND21, E2 and T levelswere similar between groups, whereas MG area, perimeter, number of terminal endbuds and ESR1 expression were increased in ENDO-exposed rats. These changeswere associated with alveolar development and increased organized collagen inthe stroma. On PND60, a higher proliferation index in ENDO-exposed rats wascorrelated with a more developed lobuloalveolar structure. Hyperplastic alveoliand, hyperplastic ducts surrounded by a dense stroma were also observed in thisgroup. T levels and ESR1 expression were similar between groups, whereas E2levels and AR expression were decreased in ENDO-exposed rats. The exposure toENDO in the first week of life interferes with the normal development of the MGand induces pre-malignant lesions in post-pubertal male rats.