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- Benrick, Anna, 1979, et al.
(författare)
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Resveratrol Is Not as Effective as Physical Exercise for Improving Reproductive and Metabolic Functions in Rats with Dihydrotestosterone-Induced Polycystic Ovary Syndrome
- 2013
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Ingår i: Evidence-Based Complementary and Alternative Medicine. - : Hindawi Limited. - 1741-427X .- 1741-4288.
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Tidskriftsartikel (refereegranskat)abstract
- Polycystic ovary syndrome (PCOS) is a reproductive and metabolic disorder associated with obesity and insulin resistance that often precedes the development of type-2 diabetes. Rats continuously exposed to dihydrotestosterone from prepuberty display typical reproductive and metabolic PCOS characteristics including anovulation, polycystic ovaries, insulin resistance, and obesity. Our aim was to investigate if resveratrol improves reproductive and metabolic functions in PCOS rats. The effect was compared to exercise. Control and PCOS rats were treated with vehicle or resveratrol (400mg·kg−1·day−1) for 5-6 weeks. Another group of PCOS rats received vehicle treatment and exercised for 5-6 weeks. Insulin sensitivity was determined by euglycemic-hyperinsulinemic clamp. The glucose infusion rate was lower in the PCOS-vehicle group compared to control-vehicle rats (). Exercise increased insulin sensitivity compared with PCOS-vehicle rats (), but resveratrol did not. Resveratrol treatment and exercise resulted in smaller adipocytes, upregulated estrogen-related receptor α gene expression in subcutaneous fat, and improved estrus cyclicity in the previously acyclic PCOS rats. Although resveratrol had positive effects on adiposity and cyclicity in a similar manner to exercise, resveratrol does not seem to be a good candidate for treating insulin resistance associated with PCOS because no improvement in insulin sensitivity was observed in PCOS rats on normal chow.
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| 2. |
- Maliqueo, Manuel, et al.
(författare)
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Continuous Administration of a P450 Aromatase Inhibitor Induces Polycystic Ovary Syndrome with a Metabolic and Endocrine Phenotype in Female Rats at Adult Age
- 2013
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Ingår i: Endocrinology. - : The Endocrine Society. - 0013-7227 .- 1945-7170. ; 154:1, s. 434-445
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Tidskriftsartikel (refereegranskat)abstract
- Studying the mechanisms for the complex pathogenesis of polycystic ovary syndrome (PCOS) requires animal models with endocrine, reproductive, and metabolic features of the syndrome. Hyperandrogenism seems to be a central factor in PCOS, leading to anovulation and insulin resistance. In female rats, continuous administration of letrozole, a nonsteroidal inhibitor of P450 aromatase, at 400 mu g/d starting before puberty induces hyperandrogenemia and reproductive abnormalities similar to those in women with PCOS. However, despite high circulating testosterone levels, these rats do not develop metabolic abnormalities, perhaps because of their supraphysiological testosterone concentrations or because estrogen synthesis is completely blocked in insulin-sensitive tissues. To test the hypothesis that continuous administration of lower doses of letrozole starting before puberty would result in both metabolic and reproductive phenotypes of PCOS, we performed a 12-wk dose-response study. At 21 d of age, 46 female Wistar rats were divided into two letrozole groups (100 or 200 mu g/d) and a control group (placebo). Both letrozole doses resulted in increased body weight, inguinal fat accumulation, anovulation, larger ovaries with follicular atresia and multiples cysts, endogenous hyperandrogemia, and lower estrogen levels. Moreover, rats that received 200 mu g/d had insulin resistance and enlarged adipocytes in inguinal and mesenteric fat depots, increased circulating levels of LH, decreased levels of FSH, and increased ovarian expression of Cyp17a1 mRNA. Thus, continuous administration of letrozole, 200 mu g/d, to female rats for 90 d starting before puberty results in a PCOS model with reproductive and metabolic features of the syndrome. (Endocrinology 154: 434-445, 2013)
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