Browsing by Author "Silva, Carla Barbosa"
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- The epididymis as a target of endocrine disruption: effect on calcium homeostasisPublication . Silva, Carla Barbosa; Correia, Sara Carina de Lima; Socorro, Sílvia Cristina da Cruz Marques; Sousa, Ana Catarina AlmeidaThe epididymis is a central player in male fertility. Hormone regulation, mainly in the caput region, establishes the biochemical composition (water, ions, organic molecules) of the epididymal fluid, and it is during the transit through the epididymis, and by exposure to this unique environment, that sperm undergo the transformations required to become fully functional. Studies in knockout animals for calcium (Ca2+) channels demonstrated the importance of regulating epididymal Ca2+ levels for spermatozoa function, as these animals displayed impaired sperm motility, viability, and fertilization capacity. In recent decades, concern was raised about endocrine disruption and male fertility. Endocrine disruptors (EDs) can perturb the normal hormone signalling disrupting spermatogenesis. However, the effect of EDs in the epididymis function is largely unknown. Vinclozolin (VNZ), an endocrine disruptor (ED) with antiandrogenic activity, has been shown to affect male reproduction. The present thesis investigated the effect of VNZ on rat epididymal cells survival and function, Ca2+ homeostasis and antioxidant defences. Caput sections were cultured ex vivo in the presence or absence of VNZ 500 µM. Ca2+ levels, the expression of Ca2+-sensitive receptor (CaSR) and Ca2+ transient receptor potential vanilloid subfamily member 6 (TRPV6), the activity of glutathione peroxidase (GPX) and superoxide dismutase (SOD) and the activity of caspase-3 were assessed. CaSR and TRPV6 expression decreased in the presence of VNZ, together with an increase in the concentrations of extracellular Ca2+. Also, the activity of the antioxidant enzymes GPX and SOD and the activity of caspase-3 decreased in the VNZ-treated group. The obtained results demonstrated for the first time that VNZ dysregulates Ca2+ homeostasis and decreases the antioxidant defences in the epididymis, which indicates that the exposure to VNZ may affect sperm quality and male fertility.