Altered insulin-induced relaxation of aortic rings in a dihydrotestosterone-induced rodent model of polycystic ovary syndrome.
OBJECTIVE
To clarify the effects of dihydrotestosterone (DHT)-induced polycystic ovary syndrome (PCOS) on the insulin-dependent vasodilatation of the thoracic aorta and the role of vitamin D in a rat model.


METHODS
Controlled experimental animal study.


METHODS
Laboratory.


METHODS
Thirty adolescent female Wistar rats.


METHODS
The PCOS model was induced by 10 weeks of DHT treatment (83 μg/d). One-half of the DHT-treated animals also received vitamin D (120 ng/kg/wk).


METHODS
The aortic rings of the control, DHT, and DHT plus vitamin D-treated animals were isolated. The insulin-dependent vasodilation of the isolated aortic rings was compared in Krebs-Ringer solution and under blockade of nitric oxide (NO) synthase or cyclooxygenase.


RESULTS
The insulin-dependent vasorelaxation decreased in both DHT-treated groups independently from the vitamin D treatment; NO-dependent and -independent relaxations were both impaired. In response to prostanoid, vasoconstriction was increased after DHT treatment. The NO-independent relaxation was partially improved by vitamin D treatment, which was neutralized by increased prostanoid-dependent vasoconstriction.


CONCLUSIONS
Previously, we found that vitamin D treatment prevented systemic insulin resistance; however, in this study, we did not detect any influence on the vascular insulin resistance of the aorta that was induced by DHT treatment. Consequently, controlling insulin resistance with vitamin D alone did not resolve the aortic endothelial dysfunction caused by the hyperandrogenic state.
Department of Cardiology, Bajcsy Zs. Hospital, Budapest, Hungary.
Gabriella
G
Masszi
Anna
A
Buday
Agnes
A
Novak
Eszter Maria
EM
Horvath
Robert
R
Tarszabo
Levente
L
Sara
Csaba
C
Revesz
Rita
R
Benko
Gyorgy L
GL
Nadasy
Zoltán
Z
Benyó
Peter
P
Hamar
Szabolcs
S
Varbiro
D000818:Animals; D001011:Aorta / Q000187:drug effects / Q000503:physiopathology*; D013196:Dihydrotestosterone; D004195:Disease Models, Animal; D005260:Female; D006801:Humans; D007328:Insulin / Q000378:metabolism* / Q000494:pharmacology; D007333:Insulin Resistance; D011085:Polycystic Ovary Syndrome / Q000139:chemically induced* / Q000503:physiopathology*; D051381:Rats; D017208:Rats, Wistar; D014664:Vasodilation / Q000187:drug effects*; D014807:Vitamin D / Q000008:administration & dosage*
D007328:Insulin; D013196:Dihydrotestosterone; D014807:Vitamin D