A note on the metabolism of 5α-androst-16-en-3-one in the young boar in vivo

Abstract

Summary. The metabolism of plasma 5a-androst-16-en-3-one (androstenone) was studied in two young boars weighing about 100 kg in which a single dose of tritiated androstenone was injected intravenously. The peripheral blood of one boar was continuously sampled for 6 h after injection ; the total radioactivity per liter of plasma increased up to 14 min after the injection, and then declined rather slowly since plasma radioactivity was still measurable 7 days after injection. The metabolic clearance rate of androstenone was calculated to be about 80 000 liters per day. This quick disappearance of plasma androstenone was probably mainly due to storage in fatty tissue and, to a lesser extent, to catabolism into 5a-androst-16-en-3a-ol, 5a-androst-16-en-3¡J-ol and particularly into unknown more polar compounds of which there were at least three. Radioactivity was mainly eliminated in the urine in the form of the same unknown polar compounds.Introduction.

Immunocastration as Alternative to Surgical Castration in Pigs

“…Androstenone is synthesised from the precursors, pregnenolone and progesterone, through the formation of androstadienone by the sequential action of a number of enzymes, particularly cytochrome P450C17 and cytochrome b5 [25,26]. Androstenone is metabolised in the liver with the production of alpha-androstenol and to a greater extent beta-androstenol [27,28]. Part of androstenone is transported to the submaxillary salivary gland, where it is bind to a specific binding protein pheromaxein and released in the saliva, which among other 16-androstene steroids act as a pheromone to promote sexual behaviour in female pigs.…”

Gene expression profiles in liver of pigs with extreme high and low levels of androstenone

“…Androstenone (5α-androst-16-en-3-one) is produced in the testis and is transported by blood to the salivary gland where it functions as a pheromone to stimulate mating stance in gilts [ 5 ]. It is metabolised in the liver, producing α-androstenol and β-androstenol [ 6 , 7 ], and deficient degradation may lead to the accumulation of androstenone in adipose tissue. Skatole (3-methylindole) is produced by the metabolism of tryptophan from the gut and is also catabolised in liver.…”

Odeurs indésirables de la viande de porcs mâles non castrés : problèmes et solutions potentielles

“…La 3β-hydroxy-stéroïde déshydrogénase semble être l'enzyme majeure du métabolisme de phase 1 qui conduit à au moins deux métabolites : le 3α-androsténol et le 3β-androsténol. Les principales enzymes du métabolisme de phase 2, SULT1A1 (sulfotransférase) et UGT (uridine-di-phosphate-glucuronosyltransférase), permettent d'ajouter un groupement sulfate ou glucuronyl qui aboutit à une grande diversité de produits terminaux (Bonneau et Terqui, 1983). Cette phase 2 augmente la solubilité des métabolites et facilite leur élimination urinaire.…”

“…La demi-vie du scatol semble beaucoup plus courte que celle de l'androsténone. Après injection intraveineuse d'un produit marqué au 14 C, 85 % de la radioactivité est récupérée au bout de 24 heures pour le scatol (Friis, 1993) contre moins de 60 % au bout d'une semaine pour l'androsténone (Bonneau et Terqui, 1983). L'androsténone est produite de façon croissante au cours du développement pubertaire comme l'attestent l'augmentation simultanée des concentrations plasmatiques d'androsténone, de testostérone et d'oestradiol ainsi que le franchissement des différentes étapes de la spermatogénèse jusqu'à l'acquisition de la fertilité (Zamaratskaia et al, 2004 ;Wagner et Claus, 2008).…”