Expression of the hepatic skatole- and androstenone-metabolising enzymes in entire male pigs of two live weights

The aim of the present study was to investigate an in vivo relationship between increased levels of testicular steroids and protein expression of the key enzymes involved in hepatic metabolism of skatole (cytochrome P4502E1 and CYP2E1 and CYP2A) and androstenone (3 beta-hydroxysteroid dehydrogenase-3 beta-HSD, and sulfotransferase SULT2B1). For this purpose, we compared the protein expression in the liver from high weight (115 kg) and low weight (90 kg) pigs and related it to the level of the testicular steroids testosterone, oestrone sulphate and androstenone. We demonstrated that protein expressions of both skatole and androstenone-metabolising enzymes were affected by live weight of pigs. Expressions of CYP2E1 and 2A proteins were significantly lower (P = 0.05 and 0.001, respectively) in the liver microsomes of high weight pigs compared to that of low weight pigs. The expression of androstenone-metabolising 3 beta-HSD was also lower (P = 0.003) in high weight pigs whilst the expression of SULT2B1 was higher in high weight pigs (P= 0.036). We concluded that the age-related decrease in activities of cytochrome P4502E1 and 2A and thus increased fat skatole levels are likely due to decreased protein expression of those enzymes in older (heavier) pigs with higher levels of testicular steroids. The age-related increase in androstenone levels can be at least partly due to decreased protein expression of 3 beta-hydroxysteroid dehydrogenase, but not SULT2B1. (C) 2012 Elsevier B.V. All rights reserved.