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Human Efflux Transport of Testosterone, Epitestosterone and Other Androgen Glucuronides.

Abstract

Several drug-metabolizing enzymes are known to control androgen homeostasis in humans. UDP-glucuronosyltransferases convert androgens to glucuronide conjugates in the liver and intestine, which enables subsequent elimination of these conjugated androgens via urine. The most important androgen is testosterone, while other important ones are the testosterone metabolites androsterone and etiocholanolone, and the testosterone precursor dehydroepiandrosterone. Epitestosterone is another endogenous androgen, which is included as a crucial marker in urine doping tests. Since glucuronide conjugates are hydrophilic, efflux transporters mediate their excretion from tissues. In this study, we employed the membrane vesicle assay to identify the efflux transporters for glucuronides of androsterone, dehydroepiandrosterone, epitestosterone, etiocholanolone and testosterone. The human hepatic and intestinal transporters MRP2 (ABCC2), MRP3 (ABCC3), MRP4 (ABCC4), BCRP (ABCG2) and MDR1 (ABCB1) were studied in vitro. Of these transporters, only MRP2 and MRP3 transported the androgen glucuronides investigated. In kinetic analyses, MRP3 transported glucuronides of androsterone, epitestosterone and etiocholanolone at low Km values, between 0.4 and 4 µM, while the Km values for glucuronides of testosterone and dehydroepiandrosterone were 14 and 51 µM, respectively. MRP2 transported the glucuronides at lower affinity, as indicated by Km values over 100 µM. Interestingly, the MRP2-mediated transport of androsterone and epitestosterone glucuronides was best described by sigmoidal kinetics. The inability of BCRP to transport any of the androgen glucuronides investigated is drastically different from its highly active transport of several estrogen conjugates. Our results explain the transporter mediated disposition of androgen glucuronides in humans, and shed light on differences between the human efflux transporters MRP2, MRP3, MRP4, BCRP and MDR1.

Authors+Show Affiliations

Drug Research Program, Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, Finland. Electronic address: erkka.jarvinen@helsinki.fi.Drug Research Program, Division of Pharmaceutical Biosciences, Faculty of Pharmacy, University of Helsinki, Finland.Drug Research Program, Division of Pharmaceutical Chemistry and Technology, Faculty of Pharmacy, University of Helsinki, Finland.

Pub Type(s)

Journal Article

Language

eng

PubMed ID

31704245

Citation

Järvinen, Erkka, et al. "Human Efflux Transport of Testosterone, Epitestosterone and Other Androgen Glucuronides." The Journal of Steroid Biochemistry and Molecular Biology, 2019, p. 105518.
Järvinen E, Kidron H, Finel M. Human Efflux Transport of Testosterone, Epitestosterone and Other Androgen Glucuronides. J Steroid Biochem Mol Biol. 2019.
Järvinen, E., Kidron, H., & Finel, M. (2019). Human Efflux Transport of Testosterone, Epitestosterone and Other Androgen Glucuronides. The Journal of Steroid Biochemistry and Molecular Biology, p. 105518. doi:10.1016/j.jsbmb.2019.105518.
Järvinen E, Kidron H, Finel M. Human Efflux Transport of Testosterone, Epitestosterone and Other Androgen Glucuronides. J Steroid Biochem Mol Biol. 2019 Nov 5;105518. PubMed PMID: 31704245.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Human Efflux Transport of Testosterone, Epitestosterone and Other Androgen Glucuronides. AU - Järvinen,Erkka, AU - Kidron,Heidi, AU - Finel,Moshe, Y1 - 2019/11/05/ PY - 2019/07/18/received PY - 2019/10/25/revised PY - 2019/10/26/accepted PY - 2019/11/10/entrez PY - 2019/11/11/pubmed PY - 2019/11/11/medline KW - ABCB1 KW - ABCC2 KW - ABCC3 KW - ABCC4 KW - ABCG2 KW - androgen SP - 105518 EP - 105518 JF - The Journal of steroid biochemistry and molecular biology JO - J. Steroid Biochem. Mol. Biol. N2 - Several drug-metabolizing enzymes are known to control androgen homeostasis in humans. UDP-glucuronosyltransferases convert androgens to glucuronide conjugates in the liver and intestine, which enables subsequent elimination of these conjugated androgens via urine. The most important androgen is testosterone, while other important ones are the testosterone metabolites androsterone and etiocholanolone, and the testosterone precursor dehydroepiandrosterone. Epitestosterone is another endogenous androgen, which is included as a crucial marker in urine doping tests. Since glucuronide conjugates are hydrophilic, efflux transporters mediate their excretion from tissues. In this study, we employed the membrane vesicle assay to identify the efflux transporters for glucuronides of androsterone, dehydroepiandrosterone, epitestosterone, etiocholanolone and testosterone. The human hepatic and intestinal transporters MRP2 (ABCC2), MRP3 (ABCC3), MRP4 (ABCC4), BCRP (ABCG2) and MDR1 (ABCB1) were studied in vitro. Of these transporters, only MRP2 and MRP3 transported the androgen glucuronides investigated. In kinetic analyses, MRP3 transported glucuronides of androsterone, epitestosterone and etiocholanolone at low Km values, between 0.4 and 4 µM, while the Km values for glucuronides of testosterone and dehydroepiandrosterone were 14 and 51 µM, respectively. MRP2 transported the glucuronides at lower affinity, as indicated by Km values over 100 µM. Interestingly, the MRP2-mediated transport of androsterone and epitestosterone glucuronides was best described by sigmoidal kinetics. The inability of BCRP to transport any of the androgen glucuronides investigated is drastically different from its highly active transport of several estrogen conjugates. Our results explain the transporter mediated disposition of androgen glucuronides in humans, and shed light on differences between the human efflux transporters MRP2, MRP3, MRP4, BCRP and MDR1. SN - 1879-1220 UR - https://www.unboundmedicine.com/medline/citation/31704245/Human_Efflux_Transport_of_Testosterone,_Epitestosterone_and_Other_Androgen_Glucuronides L2 - https://linkinghub.elsevier.com/retrieve/pii/S0960-0760(19)30430-3 DB - PRIME DP - Unbound Medicine ER -