Assessment of the effects of bisphenol-A as a disruptor on ionic regulation in Danio rerio zebrafish through a study of their chloride and prolactin cells

Abstract

Bisphenol A (BPA) is one of the chemicals produced in the largest volume in the world. It is commonly used as a component of plastics and food containers and can act as a xenoestrogen in humans. In view of the risk of exposure to it from the environment and diet, and basically as a water pollutant, the objective of our study was to assess possible effects on ionic regulation after exposure to BPA by means of a histopathological and morphometric study of the chloride and prolactin cells in zebrafish (Danio rerio) as an experimental model. Twenty-five male 16-week old zebrafish (Danio rerio) were allocated randomly into 5 study groups (n=5/group); a control group, and four groups, exposed for 2 weeks to a concentration of (1, 10, 100 and 1000 μg/L) of BPA, respectively. After 2 weeks, the animals were sacrificed and samples of their gills and pituitary gland were immediately taken for their subsequent histopathological analysis. Our results showed how, in the first study groups, lesions appeared in chloride cells, generating compensatory modifications in the prolactin cells, which were enough to maintain stability in the ionic exchange. As the exposure concentration increased, more serious histological modifications occurred. In the groups with the highest concentration (100 and 1000 μg/L), the lesions were so severe that the prolactin cells underwent some degenerative processes, which probably prevented the compensatory action at gill level.