Quick Search:

is currently disabled due to reindexing of the ZORA database. Please use Advanced Search.
uzh logo
Browse by:
bullet
bullet
bullet
bullet

Zurich Open Repository and Archive 

Permanent URL to this publication: http://dx.doi.org/10.5167/uzh-16294

Dubey, R K; Jackson, E K; Gillespie, D G; Zacharia, L C; Wunder, D; Imthurn, B; Rosselli, M (2008). Medroxyprogesterone abrogates the inhibitory effects of estradiol on vascular smooth muscle cells by preventing estradiol metabolism. Hypertension, 51(4):1197-1202.

[img]
Preview
Accepted Version
PDF
1MB

Abstract

Sequential conversion of estradiol (E) to 2/4-hydroxyestradiols and 2-/4-methoxyestradiols (MEs) by CYP450s and catechol-O-methyltransferase, respectively, contributes to the inhibitory effects of E on smooth muscle cells (SMCs) via estrogen receptor-independent mechanisms. Because medroxyprogesterone (MPA) is a substrate for CYP450s, we hypothesized that MPA may abrogate the inhibitory effects of E by competing for CYP450s and inhibiting the formation of 2/4-hydroxyestradiols and MEs. To test this hypothesis, we investigated the effects of E on SMC number, DNA and collagen synthesis, and migration in the presence and absence of MPA. The inhibitory effects of E on cell number, DNA synthesis, collagen synthesis, and SMC migration were significantly abrogated by MPA. For example, E (0.1micromol/L) reduced cell number to 51+/-3.6% of control, and this inhibitory effect was attenuated to 87.5+/-2.9% by MPA (10 nmol/L). Treatment with MPA alone did not alter any SMC parameters, and the abrogatory effects of MPA were not blocked by RU486 (progesterone-receptor antagonist), nor did treatment of SMCs with MPA influence the expression of estrogen receptor-alpha or estrogen receptor-beta. In SMCs and microsomal preparations, MPA inhibited the sequential conversion of E to 2-2/4-hydroxyestradiol and 2-ME. Moreover, as compared with microsomes treated with E alone, 2-ME formation was inhibited when SMCs were incubated with microsomal extracts incubated with E plus MPA. Our findings suggest that the inhibitory actions of MPA on the metabolism of E to 2/4-hydroxyestradiols and MEs may negate the cardiovascular protective actions of estradiol in postmenopausal women receiving estradiol therapy combined with administration of MPA.

Item Type:Journal Article, refereed, original work
Communities & Collections:04 Faculty of Medicine > Center for Integrative Human Physiology
04 Faculty of Medicine > University Hospital Zurich > Clinic for Reproductive Endocrinology
DDC:570 Life sciences; biology
610 Medicine & health
Language:English
Date:2008
Deposited On:24 Feb 2009 14:07
Last Modified:18 Jul 2014 07:13
Publisher:American Heart Association
ISSN:0194-911X
Additional Information:Full text article at http://hyper.ahajournals.org/cgi/reprint/51/4/1197
Publisher DOI:10.1161/HYPERTENSIONAHA.107.106575
PubMed ID:18259021
Citations:Web of Science®. Times Cited: 7
Google Scholar™
Scopus®. Citation Count: 8

Users (please log in): suggest update or correction for this item

Repository Staff Only: item control page