The activity of paraoxonase type 1 (PON‐1) in boar seminal plasma and its relationship with sperm quality, functionality, and in vivo fertility. (19th January 2015) - Barranco, I.
Summary: Paraoxonase 1 (PON‐1) is a hydrolytic enzyme present in body fluids, capable of protecting cells against oxidative stress. The hypothesis was hereby to test that PON‐1, present in seminal plasma (SP), acts protecting boar spermatozoa when showing a reasonable high activity in the ejaculate. SP‐PON‐1 activity differed ( p < 0.001) among boars (from 0.10 to 0.29 IU/mL). Intra‐boar variability was also observed ( p < 0.05), but only in two of the 15 boars. SP‐PON‐1 activity differed among ejaculate portions, showing the spermatozoa‐peak portion of spermatozoa‐rich ejaculate fraction the highest levels (0.35 ± 0.03 IU/mL, ranging from 0.12 to 0.69) and the post‐sperm ejaculate fraction the lowest levels (0.12 ± 0.01 IU/mL, ranging from 0.03 to 0.21). SP‐PON‐1 activity was positively correlated with the percentage of spermatozoa with rapid and progressive movement ( p < 0.01) and negatively correlated with the generation of intracellular reactive oxygen species ( p < 0.01) in semen samples after 72 h of liquid storage. SP‐PON‐1 activity was highest ( p < 0.01) in boars with highest farrowing rates. In conclusion, SP‐PON‐1 activity differed among boars and ejaculate fractions/portions. SP‐PON‐1 activity was positively correlated with sperm quality and functionality of liquid‐stored semen samples and it evidenced a positive association with in vivo fertility.