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| References
- Heart,
circulation, and the effects of testosterone. |
3.
Alexandersen P, Haarbo J, Byrjalsen I, Lawaetz H,
Christiansen C. Natural androgens inhibit male atherosclerosis:
a study in castrated, cholesterol-fed rabbits. Circulation
Research.1997;84:813-819.
Abstract: The effect of natural androgens on serum lipids
and atherosclerosis is controversial. We therefore studied this
important issue prospectively in an animal model of atherosclerosis.
Eighty male rabbits were randomized to bilateral castration,
and 20 animals were sham operated. The castrated rabbits were
randomized to 500 mg oral dehydroepiandrosterone (DHEA) daily,
80 mg oral testosterone undecanoate (TU) daily, or 25-mg intramuscular
injection of testosterone enanthate (TE) twice weekly, whereas
the fourth castrated group (placebo) and the sham-operated rabbits
did not receive any hormones. All animals were fed a cholesterol-rich
diet during the 30-week treatment period. Average serum lipids
and atherogenic lipoproteins were higher in the placebo group
than in the other groups (ANOVA, P<0.0001). Aortic atherosclerosis,
as evaluated by the cholesterol content (nmol/mg protein), was
also highest in the placebo group (308+/-39) and lowest in the
TE group (61+/-12), but was intermediate in the DHEA (155+/-30),
TU (191+/-43), and sham operation (162+/-29) groups (ANOVA,
P<0.0001). ANCOVA indicated that the androgen effect on aortic
atherosclerosis was only in part explained by the changes in
lipoproteins. Aortic estrogen receptor contents were significantly
lower in the androgen-treated groups than in the control groups,
whereas there was no difference in aortic androgen receptor
contents between groups. Natural androgens inhibit aortic atherosclerosis
in castrated male rabbits only partly through a lipid-mediated
effect.
Notes: Testosterone in this classic artificial experimental
model of causing arterial degeneration in rabbits by a gross
dietary excess of cholesterol, protected the arteries both against
high blood fat levels and by other mechanisms.
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