Abstract

GONZALEZ-GONZALEZ, Alicia et al. A single neonatal administration of soybean oil and/or tamoxifen permanently affects testis histomorphology in adult rats. Veterinaria México OA [online]. 2016, vol.3, n.2. ISSN 2448-6760.  https://doi.org/10.21753/vmoa.3.2.364.

The aim of this study was to evaluate the effects of administration of tamoxifen (Tx) and its vehicle, soybean oil (SO), during the critical period of hypothalamic sexual differentiation in newborn male rats in the context of gonadal histomorphology during adulthood. The animals were randomly divided into 3 groups (n = 5 each). One hour after birth, one group was treated subcutaneously with 200 μg of Tx using commercial SO (20 µL) as a vehicle, another group was treated with only 20 μL of SO, and the control group received no treatment. All rats were weighed and sacrificed by cervical dislocation on day 90 post-treatment. Testicles were removed, weighed and processed for histological evaluation. The single administration of Tx and/or SO during the critical period of sexual differentiation of the hypothalamus permanently altered testicular histomorphology, spermatogenesis, and body weight in adulthood. Alterations included vacuolization and reduction in the number of spermatogonia and Sertoli cells. The administration of Tx reduced testicular weight, the diameter and area of the seminiferous tubules, and the height of the germinal epithelium and increased the intertubular space. Soybean oil by itself reduced the number of spermatocytes and spermatids to a greater extent than Tx. There was no effect on the number of Leydig cells. The possibility that soybean oil can act as an endocrine disruptor deserves greater attention and opens the possibility for the development of new pest control methods.

Keywords : Endocrine disruptors; Tamoxifen; Soybean oil; Sexual differentiation of the hypothalamus; Testicular morphology.