Steroidogenic machinery in the adult rat colon

• Published in: The Journal of steroid biochemistry and molecular biology 2020-10, Vol.203, p.105732-105732, Article 105732
• Main Authors: Diviccaro, S., Giatti, S., Borgo, F., Falvo, E., Caruso, D., Garcia-Segura, L.M., Melcangi, R.C.
• Format: Article
• Language: English
• Subjects: 17β-Estradiol; Adrenal glands; Animals; Cerebral cortex; Cerebral Cortex - metabolism; Colon; Colon - metabolism; Digestive system; Dihydrotestosterone; Enteric nervous system; Gastrointestinal tract; Gonads; Gut; Intestinal microflora; Liquid chromatography-tandem mass spectrometry; Male; Metabolism; Metabolites; Microbiota; Neuroactive steroids; Pregnenolone; Progesterone; Rats, Sprague-Dawley; Rodents; Sex steroids; Steroid hormones; Steroidogenesis; Steroidogenic enzymes; Steroids - blood; Steroids - metabolism; Testosterone; Tetrahydroprogesterone
• ISSN: 0960-0760; 1879-1220
• DOI: 10.1016/j.jsbmb.2020.105732

•Adult rat colon expresses molecules involved in the early steps of steroidogenesis.•Synthesis and metabolism of sex steroids also occurred.•Levels of pregnenolone and progesterone and testosterone metabolites are higher in colon than in plasma.•Higher levels of 3α-diol were detected in the colon in comparison with cerebral cortex. Gastrointestinal function is known to be regulated by steroid molecules produced by the gonads, the adrenal glands and the gut microbiota. However, we have a limited knowledge on the functional significance of local steroid production by gastrointestinal tract tissue. On this basis, we have here evaluated, as a first methodological approach, the expression of steroidogenic molecules and the local levels of key steroids in the male rat colon. Our findings indicate that the colon tissue expresses molecules involved in the early steps of steroidogenesis and in the consecutive synthesis and metabolism of steroid hormones, such as progesterone, testosterone and 17β-estradiol. In addition, the levels of the steroid hormone precursor pregnenolone and the levels of active metabolites of progesterone and testosterone, such as dihydroprogesterone, tetrahydroprogesterone, dihydrotestosterone and 17β-estradiol, were higher in colon than in plasma. Higher levels of the androgen metabolite 3α-diol were detected in the colon in comparison with another non-classical steroidogenic tissue, such as the cerebral cortex. These findings suggest the existence of local steroid synthesis and metabolism in the colon, with the production of active steroid metabolites that may impact on the activity of the enteric nervous system and on the composition of the gut microbiota.