title: Treatment of ovariectomized rats with 17β-estradiol increases hepatic delta-6 desaturase enzyme expression and docosahexaenoic acid levels in hepatic and plasma phospholipids.
abstract: Higher docosahexaenoic acid (DHA) in females compared with males suggests ovarian hormones increase DHA production. Eight-week old rats were ovariectomized or sham operated (SHAM), and ovariectomized rats were treated with implanted pellets providing 17β-estradiol (OVX+E), progesterone (OVX+P), both (OVX+PE) or neither (OVX) for 14 days. Immunoblot and fatty acid analysis were performed on all samples, and microarray analysis was performed on OVX and SHAM groups. Increased Δ6-desaturase in OVX relative to SHAM was observed by microarray (12% higher) and immunoblot (31% higher). OVX+E and OVX+PE rats had 39% and 42% higher Δ6-desaturase content, respectively, compared with OVX. OVX+E and OVX+PE also increased phospholipid DHA concentrations in liver (increase of 34% and 40%, respectively) and plasma (increase of 70% and 74%, respectively) relative to OVX. Progesterone exerted no effect on Δ6-desaturase or DHA. These results indicate that 17β-estradiol increases DHA through increased Δ6-desaturase, possibly explaining sex differences in DHA.
authors.affiliation: Department of Kinesiology, University of Waterloo, Waterloo, ON, Canada N2L 3G1.
authors.forename: Alex P
authors.initials: AP
authors.lastname: Kitson
authors.forename: Kristin A
authors.initials: KA
authors.lastname: Marks
authors.forename: Brittany
authors.initials: B
authors.lastname: Shaw
authors.forename: David M
authors.initials: DM
authors.lastname: Mutch
authors.forename: Ken D
authors.initials: KD
authors.lastname: Stark
mesh_terms: D000818:Animals; D004281:Docosahexaenoic Acids / Q000378:metabolism*; D004958:Estradiol / Q000494:pharmacology*; D015525:Fatty Acids, Omega-3; D005260:Female; D050602:Linoleoyl-CoA Desaturase / Q000378:metabolism*; D008099:Liver / Q000187:drug effects* / Q000201:enzymology* / Q000378:metabolism; D010052:Ovariectomy; D010743:Phospholipids / Q000097:blood*; D051381:Rats
chemical_list: D015525:Fatty Acids, Omega-3; D010743:Phospholipids; D004281:Docosahexaenoic Acids; D004958:Estradiol; D050602:Linoleoyl-CoA Desaturase
keywords: Delta-6 desaturase; Docosahexaenoic acid; Omega-3 polyunsaturated fatty acids; Ovariectomy; Sex hormones