Genotype and phenotype frequencies of paraoxonase 1 in fertile and infertile men

Abstract

Paraoxonase1 (PON1) is a glycoprotein associated with high density lipoprotein and has antioxidant activity. The impact of PON1 in various stages of spermatogenesis has also been suggested. This study was aimed to investigate frequencies of phenotypes and Q192R genotypes of PON1 in fertile and infertile males. Q192R variants of PON1 were determined in 150 fertile and 150 infertile men using the polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique. Plasma arylesterase and paraoxonase activities were detected by spectrophotometry and malondialdehyde (MDA) level was measured using thiobarbituric acid. Our results showed no significant difference in the distribution of PON1 genotypes and alleles between fertile and infertile groups. However morphology and motility of sperm were associated with various genotypes of PON1. The number of fertile males with the BB phenotype (high activity) was significantly higher than that of infertile males, whereas the number of individuals with the AB phenotype (moderate activity) was statistically higher in infertile men compared with the fertile group. Additionally, MDA and arylesterase activity levels were significantly higher in infertile subjects compared with fertile men. We speculate that the low activity of PON1 can be a risk factor for male infertility probably due to a decrease in antioxidant activity of PON1 and increase in lipid peroxidation.