title: Angiotensin II type 2 receptor stimulation improves fatty acid ovarian uptake and hyperandrogenemia in an obese rat model of polycystic ovary syndrome.
abstract: Polycystic ovary syndrome (PCOS) is mainly defined by hyperandrogenism but is also characterized by insulin resistance (IR). Studies showed that overexposure of nonadipose tissues to nonesterified fatty acids (NEFA) may explain both IR and hyperandrogenism. Recent studies indicate that treatment with an angiotensin II type 2 receptor (AT2R)-selective agonist improves diet-induced IR. We thus hypothesized that PCOS hyperandrogenism is triggered by ovarian NEFA overexposure and is improved after treatment with an AT2R agonist. Experiments were conducted in 12-week-old female JCR:LA-cp/cp rats, which are characterized by visceral obesity, IR, hyperandrogenism, and polycystic ovaries. Control JCR:LA +/? rats have a normal phenotype. Rats were treated for 8 days with saline or the selective AT2R agonist C21/M24 and then assessed for: 1) fasting testosterone, NEFA, and insulin levels; and 2) an iv 14(R,S)-[(18)F]fluoro-6-thia-heptadecanoic acid test to determine NEFA ovarian tissue uptake (Km). Compared with controls, saline-treated PCOS/cp rats displayed higher insulin (100 vs 5.6 μU/mL), testosterone (0.12 vs 0.04 nmol/L), NEFA (0.98 vs 0.48 mmol/L), and Km (20.7 vs 12.9 nmol/g·min) (all P < .0001). In PCOS/cp rats, C21/M24 did not significantly improve insulin or NEFA but normalized testosterone (P = .004) and Km (P = .009), which were strongly correlated together in all PCOS/cp rats (ρ = 0.74, P = .009). In conclusion, in an obese PCOS rat model, ovarian NEFA uptake and testosterone levels are strongly associated and are both significantly reduced after short-term C21/M24 therapy. These findings provide new information on the role of NEFA in PCOS hyperandrogenemia and suggest a potential role for AT2R agonists in the treatment of PCOS.
authors: Division of Endocrinology (S.L., M.-C.B., C.N., N.G.-P., A.C.C., J.-P.B.), Department of Medicine, Faculty of Medicine and Health Sciences, Université de Sherbrooke, Sherbrooke, Quebec, Canada J1H 5N4; Department of Medicinal Chemistry (A.H.), Biomedicinska Centrum, Uppsala University, Uppsala, Sweden 751 23; Alberta Institute for Human Nutrition, Metabolic and Cardiovascular Disease Laboratory (D.F.V.), University of Alberta, Edmonton, Alberta, Canada T6G 2E1; and Centre de Recherche Étienne-Lebel (N.G.-P., A.C.C., J.-P.B.), Centre Hospitalier Universitaire de Sherbrooke, Sherbrooke, Quebec, Canada J1H 5N4.
authors: Samuel
authors: S
authors: Leblanc
authors: Marie-Claude
authors: MC
authors: Battista
authors: Christophe
authors: C
authors: Noll
authors: Anders
authors: A
authors: Hallberg
authors: Nicole
authors: N
authors: Gallo-Payet
authors: André C
authors: AC
authors: Carpentier
authors: Donna F
authors: DF
authors: Vine
authors: Jean-Patrice
authors: JP
authors: Baillargeon
mesh_terms: D000818:Animals; D005227:Fatty Acids / Q000378:metabolism*; D005260:Female; D006801:Humans; D017588:Hyperandrogenism / Q000150:complications / Q000235:genetics / Q000378:metabolism*; D007328:Insulin / Q000097:blood; D007333:Insulin Resistance; D009765:Obesity / Q000150:complications / Q000235:genetics / Q000378:metabolism*; D010053:Ovary / Q000378:metabolism*; D011085:Polycystic Ovary Syndrome / Q000150:complications / Q000235:genetics / Q000378:metabolism*; D051381:Rats; D055647:Rats, Transgenic; D044139:Receptor, Angiotensin, Type 2 / Q000819:agonists / Q000235:genetics / Q000378:metabolism*; D013739:Testosterone / Q000097:blood; D015854:Up-Regulation
chemical_list: D005227:Fatty Acids; D007328:Insulin; D044139:Receptor, Angiotensin, Type 2; D013739:Testosterone