Bisphenol A modifies human spermatozoa motility in vitro

Abstract

Introduction. The decrease of men’s sperm quality was reported to be related to exposure to xenoestrogens. Bisphenol-A (BPA) is a synthetic xenoestrogen commonly present in our environment, for instance in food containers. Aim. The aim of this study was to investigate the influence of BPA on human spermatozoa motility. Material and methods. The effects on spermatozoa of BPA at final concentrations of 10–10, 10–8 and 10–6 mol/L were studied regarding to the following phenomena: (1) evaluation of sperm motility using computer-aided sperm analysis system providing four parameters: velocity straight linear VSL, cross beat frequency CBF, lateral head displacement LHD and homogeneity of progressive movement velocity HPMV, (2) spermatozoa vitality (propidium iodide staining), (3) phosphatidylserine membrane translocation (staining with annexin V conjugated with fluorescein) and (4) kinetics of intracellular free calcium ions changes (using Fluo-3). Results. BPA caused a transient, significant increase of VSL and HPMV at 15 minutes after stimulation. One hour incubation of spermatozoa with BPA did not alter cells vitality nor stimulated phosphatidylserine membrane translocation, for all three concentrations. BPA in the final concentration of 10–6 mol/L initiated a rapid (observed after a few seconds), and transient (resolving after a few minutes) increase of intracellular free calcium ions concentration. Conclusions. Human spermatozoa can be considered target cells for BPA. BPA significantly modified spermatozoa motility. BPA affected spermatozoa involving free calcium ions as second messenger.

Keywords

• bisphenol A
• human spermatozoa
• sperm cells motility