The sulfoconjugation of androstenone and dehydroepiandrosterone by human and porcine sulfotransferase enzymes

Pork Production with Entire Males: Directions for Control of Boar Taint

“…Phase I metabolism produces androstenol metabolites of androstenone through 3α-hydroxy and 3βhydroxy reduction [26]. Androstenone and its metabolites can then be conjugated to a sulfate or glucuronide group during Phase II metabolism by the cytosolic sulfotransferase enzyme SULT2A1, or by UDP-glucuronosyltransferase (UGTs), respectively [27,28]. It was suggested from Western blotting analysis that SULT2B1 may also be involved in the sulfoconjugation of androstenone [29], The synthesis of androstadienol from pregnenolone is catalyzed by the andien-β synthase system [14] which includes cytochrome P45017A1 (CYP17A1), with cytochrome b5 (CYB5A) acting as an electron shuttle with cytochrome P450 reductase (POR).…”

“…This suggests that androstenone sulfate may function like many steroid sulfates, acting as a steroid reservoir that can be enzymatically deconjugated by steroid sulfatase (STS) to return free androstenone [31,32]. but subsequent cloning and expression of porcine SULT2B1 demonstrated that this was not the case [27]. Approximately 70% of the 16-androstene steroids produced in the Leydig cells are present as sulfoconjugates in the peripheral circulation [30,31]; no glucuronidated forms of androstenone have been identified from Leydig cell culture.…”

The Uptake and Deconjugation of Androstenone Sulfate in the Adipose Tissue of the Boar

“…Human embryonic kidney (HEK293FT) cells purchased from ATCC (Manassas, VA. USA) were used to synthesize [ 3 H]-androstenone sulfate as previously described by Bone and Squires [ 11 ]. Briefly, confluent HEK293FT cells were transfected with 6 µg/plate of the porcine sulfotransferase SULT2A1 (pSULT2A1) expression vector constructed as previously described by Laderoute et al [ 2 ], and, after 48 h, treated with radiolabeled [ 3 H]-androstenone (8 million CPM, 36 µCi/µmol, 0.1% ethanol). Cell culture media was collected 24 h later and analyzed by reverse-phase C18 HPLC using a Luna 5µ C18(2) HPLC column (250 × 4.60 mm) purchased from Phenomenex (Torrance, CA, USA).…”

“…The elution of radiolabeled androstenone and androstenone sulfate occurred at approximately 32 and 16 min, respectively, and was monitored by a β-RAM model 2 isotope detector (IN/US Systems, Brandon, FL, USA). Radiolabeled androstenone sulfate was then isolated from the media by solid phase extraction using Sep-Pak C18 solid-phase chromatography cartridges (Waters, Milford, MA, USA), as previously described by Laderoute et al [ 2 ]. The sulfated steroid fraction was dried under nitrogen and reconstituted in 100% ethanol.…”

“…Boar taint is an undesirable flavor or odor that develops in heated pork products from entire male pigs and is caused by the accumulation of androstenone (5α-androst-16-en-3-one) and skatole (3-methylindole) in the adipose tissue [ 1 ]. Androstenone is a sex pheromone that is synthesized in the testis during steroidogenesis and is sulfoconjugated by the sulfotransferase enzyme SULT2A1 before entering the systemic circulation [ 2 , 3 ]. Androstenone sulfate is the predominant form of androstenone in the peripheral plasma of the boar, accounting for approximately 70% of the total androstenone present in the circulation [ 3 , 4 ].…”