Reduced concentration of androstenone and upregulation of 3β-hydroxysteroid dehydrogenase and 17β-hydroxysteroid dehydrogenase mRNA levels by active immunisation against gonadotropin releasing hormone I.

The aim of this study was to investigate the efficacy of active immunisation against recombinant maltose binding protein-gonadotropin releasing hormone I (MBP-GnRH-I6) in preventing boar taint. The concentrations of testosterone and anti-GnRH-I antibodies in serum were determined by radioimmunoassay and enzyme linked immunosorbent assay, respectively. The mRNA levels of 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-hydroxysteroid dehydrogenase (17β-HSD) in testes were analysed by real time quantitative PCR. The concentrations of androstenone and 3-methylindole in backfat were assayed by HPLC. Active immunisation against MBP-GnRH-I6 increased the serum concentration of anti-GnRH-I antibodies (P<0.05) and the levels of 3β-HSD and 17β-HSD mRNA in testis. However, it reduced the serum concentrations of testosterone (P<0.05) and androstenone. The concentration of 3-methylindole in backfat (P>0.05) was not changed. Thus, we conclude that vaccination against MBPGnRH- I6 is a practical and effective method to suppress the synthesis of androstenone. [ABSTRACT FROM AUTHOR]