Faculty Collaboration Database

Down regulation of hepatic flavin-containing monooxygenase activity by 17 beta-estradiol in rainbow trout (Oncorhynchus mykiss). Comp Biochem Physiol C Pharmacol Toxicol Endocrinol 1997 Oct;118(2):199-202

Date

01/24/1998

Pubmed ID

9490186

DOI

10.1016/s0742-8413(97)00139-4

Scopus ID

2-s2.0-0031469074 (requires institutional sign-in at Scopus site)   9 Citations

Abstract

Expression of flavin-containing monooxygenase (FMO) activity has been shown to be directly correlated with salinity in euryhaline fish. Sex steroids play a significant role in osmoregulation in euryhaline fish. The effects of 17 beta-estradiol and testosterone on hepatic FMO activity (N,N-dimethylaniline N-oxygenase; thiourea S-oxygenase) and expression was examined in 6-month-old and 1-year-old rainbow trout (Oncorhynchus mykiss). Fish were treated with 3 mg/kg of each compound on days 1, 4, 7, 10, 13, and 15 with euthanasia on day 19. Treatment of 6-month-old and 1-year-old female rainbow trout with testosterone or estradiol significantly reduced FMO-catalyzed DMA N-oxygenase activity in liver. However, testosterone treatment failed to significantly alter thiourea S-oxidase in 1-year-old males, although 17 beta-estradiol significantly reduced FMO activity. These results parallel those of studies showing repressive effects of sex steroids on branchial chloride cells and Na+K+ATPase of salmonids and provide further evidence of a role for FMO in teleost osmoregulation.

Author List

Schlenk D, El-Alfy A, Buhler DR

Author

Abir El-Alfy PhD Assistant Dean, Professor in the School of Pharmacy Administration department at Medical College of Wisconsin

MESH terms used to index this publication - Major topics in bold

Animals
Down-Regulation
Estradiol
Female
Liver
Male
Oncorhynchus mykiss
Oxygenases
Testosterone