Lack of difference among progestins on the anti-atherogenic effect of ethinyl estradiol: a rabbit study.
BACKGROUND
Progestins in combination with estrogen are believed to have different effects on the cardiovascular system. The aim of this study was to investigate the influence of different oral contraceptive formulations on the development of experimental atherosclerosis and vascular reactivity.


METHODS
A total of 160 sexually mature rabbits were ovariectomized and randomly assigned to equally large groups: (i) a cholesterol-rich diet (320 mg/day), either given alone (placebo), or together with (ii) ethinyl estradiol (EE 70 micro g/day, oral), (iii) desogestrel (DSG 525 micro g/day, oral), (iv) gestodene (GSD 262.5 micro g/day, oral), (v) levonorgestrel (LNG 525 micro g/day, oral), (vi) EE + DSG, (vii) EE + LNG, or (viii) EE + GSD. After 31 weeks of treatment, aortic accumulation of cholesterol and vascular vasoreactivity (in vitro) were determined.


RESULTS
Progestins alone did not reduce the accumulation of cholesterol. EE alone or in combination with a progestin reduced the accumulation of cholesterol relative to placebo (P < 0.0001). Isolated vessels from EE-treated animals relaxed significantly more to physiological concentrations of acetylcholine than did placebo (P < 0.001), whereas vessels treated with EE plus a progestin showed an intermediate response.


CONCLUSIONS
The progestins investigated can be combined with EE without attenuating the anti-atherogenic effect of EE.
Alexandersen
Peter
P
Center for Clinical & Basic Research, Ballerup Byvej 222, 2750 Ballerup, Denmark. pa@ccbr.dk
Haarbo
Jens
J
Zandberg
Pieter
P
Jespersen
Jørgen
J
Skouby
Sven O
SO
Christiansen
Claus
C
D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000378:metabolism; D001161:Arteriosclerosis / Q000517:prevention & control*; D002784:Cholesterol / Q000378:metabolism; D003280:Contraceptives, Oral, Synthetic / Q000494:pharmacology; D017135:Desogestrel / Q000494:pharmacology; D004359:Drug Therapy, Combination; D004967:Estrogens / Q000494:pharmacology*; D004997:Ethinyl Estradiol / Q000494:pharmacology*; D005260:Female; D016912:Levonorgestrel / Q000494:pharmacology; D009652:Norpregnenes / Q000494:pharmacology; D011372:Progestins / Q000494:pharmacology*; D011817:Rabbits
D003280:Contraceptives, Oral, Synthetic; D004967:Estrogens; D009652:Norpregnenes; D011372:Progestins; C033273:Gestodene; D004997:Ethinyl Estradiol; D016912:Levonorgestrel; D017135:Desogestrel; D002784:Cholesterol