Relationship between the hepatic SULT2A1 protein expression and backfat androstenone level in pigs of three breeds

Excessive accumulation of androstenone in pig adipose tissue contributes to the phenomenon of boar taint, an off-odour of some cooked pork. One of the reasons for high androstenone accumulation is a low rate of androstenone metabolism in pig liver. The main enzymes involved in the hepatic androstenone metabolism are 3β-hydroxysteroid dehydrogenase (3β-HSD) and hydroxysteroid sulfotransferase (SULT2A1). It has been previously suggested that the mechanisms regulating androstenone metabolism are breed specific but the nature of the breed-specificity is not well understood and the previous study mainly focused on 3β-HSD. The present study investigated the relationship between the hepatic SULT2A1 protein expression and subcutaneous adipose tissue androstenone level in three genetically diverse breeds: Pietrain (P), Duroc x Pietrain (D) and Large White x Pietrain (LW). SULT2A1 protein expression was analysed in isolated cytosol by Western blotting. Androstenone content was determined by high resolution gas chromatography. The highest androstenone level was observed in (LW) crosses followed by (P) with the lowest level in (D). Expression of the hepatic SULT2A1 protein followed the opposite pattern with the highest level in the (D) pigs followed by (P) and the lowest values in (LW). It has been suggested that breed-specific expression of SULT2A1, the enzymes catalysing conjugative stage of hepatic androstenone metabolism, is one of the factors determining breed-differences in androstenone accumulation.