Effects of Nonylphenol on Motion Kinetics, Acrosome and Mitochondrial Membrane Potential in Frozen-Thawed Bull Sperm

Recent reports have shown that the Nonylphenol (NP), a well-known toxic environmental chemical has adverse effects on sperm in different species. Therefore, the current study was aimed to determine the deleterious effect of NP on frozen-thawed bull sperm. Sperm were exposed to different concentrations of NP (1, 10, 100, 250 and 500 mu g NP/mL) dissolved either in DMSO or Ethanol and incubated for 4 h at 37 degrees C. Sperm parameters were assessed at 0, 1st, 2nd, 3rd, and 4th h of incubation. Both percent motility and mitochondrial membrane potential (MMP) of sperm have decreased significantly (P<0.05) at dose level of >= 250 mu g NP/mL. Acrosome reaction was induced (P<0.05) even at minimal dose concentrations of 1 mu g NP/mL (P<0.05). However, the percentage of acrosome reacted sperm increased (P<0.05) with increase in dose level. In conclusion, NP impairs the sperm characteristics by adversely affecting motion kinetics, mitochondrial membrane potential and inducing premature acrosome reaction in bovine.