Norgestimate and medroxyprogesterone acetate do not attenuate the atheroprotective effects of 17beta-estradiol in ovariectomized, apolipoprotein E-deficient mice.
OBJECTIVE
To determine whether progestins counteract the cardioprotective effects of estrogen.


METHODS
Controlled animal study.


METHODS
Academic laboratory environment.


METHODS
Female apolipoprotein E-deficient mice.


METHODS
Mice were randomly assigned to groups receiving a sham operation plus placebo pellet, bilateral gonadectomy plus placebo pellet, or gonadectomy plus one of nine combinations of estrogen/progestin SC pellets.


METHODS
Total plasma cholesterol, body weight, fat depot weight, uterine weight and size, and the cross-sectional area of fatty streaks in the aortic sinus were measured in each animal.


RESULTS
After 8 weeks of treatment, plasma cholesterol levels were significantly higher only in the ovariectomized and sham-operated animals that received placebo pellets. No differences in plasma cholesterol were observed relative to the type or amount of progestin administered. There was a reduction in fatty streaks in all of the hormone treatment groups as compared with both the ovariectomized and sham-operated animals that received placebo pellets.


CONCLUSIONS
There were no significant differences in lesion area in response to estrogen alone or to estrogen plus the different types and doses of progestins.
Interdisciplinary Graduate Program in Nutritional Sciences, University of Washington, Seattle 98195, USA.
Jennifer M
JM
Shultz
Xiao Dong
XD
Zhu
Robert H
RH
Knopp
Renee C
RC
Leboeuf
Michael E
ME
Rosenfeld
D000273:Adipose Tissue / Q000473:pathology; D000818:Animals; D001057:Apolipoproteins E / Q000172:deficiency*; D001161:Arteriosclerosis / Q000473:pathology / Q000517:prevention & control*; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D004305:Dose-Response Relationship, Drug; D004958:Estradiol / Q000494:pharmacology*; D005260:Female; D007328:Insulin / Q000097:blood; D008055:Lipids / Q000097:blood; D008074:Lipoproteins / Q000097:blood; D017258:Medroxyprogesterone Acetate / Q000008:administration & dosage / Q000494:pharmacology*; D051379:Mice; D018345:Mice, Knockout; D009644:Norgestrel / Q000008:administration & dosage / Q000031:analogs & derivatives* / Q000494:pharmacology*; D009929:Organ Size / Q000187:drug effects; D010052:Ovariectomy; D011897:Random Allocation; D012850:Sinus of Valsalva / Q000473:pathology
D001057:Apolipoproteins E; D001786:Blood Glucose; D007328:Insulin; D008055:Lipids; D008074:Lipoproteins; D009644:Norgestrel; D004958:Estradiol; C017576:norgestimate; D017258:Medroxyprogesterone Acetate