title: Progesterone is actively metabolized to 5α-pregnane-3,20-dione and 3β-hydroxy-5α-pregnan-20-one by the marine mussel Mytilus galloprovincialis.
abstract: Progesterone (P4) and synthetic progestins enter the aquatic environment through wastewater treatment plant effluents and agricultural run-off, posing potential risks to aquatic organisms due to their biological activity. P4 is a precursor of a number of steroids in vertebrates, including estrogens and androgens. Mussels Mytilus galloprovincialis were exposed to P4 at the ng to low μg/L range (0.02-10μg/L) for 7 days with the aim of (a) assessing potential alterations on endogenous steroids as a consequence of exposure, and (b) describing the enzymatic pathways involved in P4 metabolism in mussels. No significant alteration of the levels of testosterone (T) and estradiol (E2) was observed in mantle/gonad tissue of exposed mussels, in spite of a 5.6-fold increase in immunoreactive T in those exposed to 10μg P4/L, which was attributed to cross-reactivity. P4 was actively metabolized to 5α-pregnane-3,20-dione (5α-DHP) and 3β-hydroxy-5α-pregnan-20-one (3β,20-one) in digestive gland, with no evidence for the synthesis of 17α-hydroxyprogesterone or androstenedione. The metabolism of P4 to 5α-DHP was not altered by exposure. Histological examination of the gonads suggested that exposure to 10μg/L P4 induced gamete maturation and release in mussels. Nonetheless, environmental concentrations of P4 are unlikely to have an endocrine action in mussels.
authors.affiliation: Environmental Chemistry Department, IDAEA-CSIC, C/Jordi Girona 18-26, 08034 Barcelona, Spain.
authors.forename: Giorgio
authors.initials: G
authors.lastname: Dimastrogiovanni
authors.affiliation: Environmental Chemistry Department, IDAEA-CSIC, C/Jordi Girona 18-26, 08034 Barcelona, Spain; FCT, CIMA, University of Algarve, Campus de Gambelas, 8005-139 Faro, Portugal. Electronic address: deniseferna@gmail.com.
authors.forename: Denise
authors.initials: D
authors.lastname: Fernandes
authors.affiliation: Environmental Chemistry Department, IDAEA-CSIC, C/Jordi Girona 18-26, 08034 Barcelona, Spain.
authors.forename: Marta
authors.initials: M
authors.lastname: Bonastre
authors.affiliation: Environmental Chemistry Department, IDAEA-CSIC, C/Jordi Girona 18-26, 08034 Barcelona, Spain. Electronic address: cinta.porte@cid.csic.es.
authors.forename: Cinta
authors.initials: C
authors.lastname: Porte
mesh_terms: D000818:Animals; D006066:Gonads / Q000187:drug effects; D049878:Mytilus / Q000378:metabolism*; D011280:Pregnanolone / Q000378:metabolism / Q000633:toxicity; D011374:Progesterone / Q000378:metabolism*; D014874:Water Pollutants, Chemical / Q000378:metabolism* / Q000633:toxicity
chemical_list: D014874:Water Pollutants, Chemical; D011374:Progesterone; D011280:Pregnanolone
keywords: 5α-reductase; Mussels; Progesterone; Steroid metabolism; Steroids