The Ossabaw Pig as a Model of Polycystic Ovary Syndrome

Abstract

Polycystic ovary syndrome (PCOS) is not only a gynecological condition, but a comprehensive syndrome with a variety of associated metabolic disorders. Our objective was to characterize endocrine parameters of female Ossabaw pigs to establish their suitability as an animal model of PCOS. Hyperandrogenism is a hallmark of PCOS, but is not associated with the metabolic syndrome in the absence of PCOS. Blood was collected from domestic pigs, Ossabaw females maintained on a low fat diet, and Ossabaw females fed a high fat, high cholesterol diet. Excess fat and cholesterol feeding elicits profound obesity, insulin resistance, increased plasma LDL/HDL cholesterol and triglycerides and coronary disease in Ossabaw swine, all characteristics of the metabolic syndrome (Dyson et al. FASEB J. 19:A191, 2005). Serum androstenedione was 4-fold greater (P<0.05) in Ossabaw females fed excess fat. Lean Ossabaw females had 4-fold greater circulating testosterone than lean domestic females. Ossabaw females fed excess fat, which exhibited the metabolic syndrome, showed 8-fold greater testosterone than lean domestic females. Androstenedione production in cultured theca cells, in response to insulin and LH stimulation, was ~2-fold greater in Ossabaw than domestic gilts. In conclusion, PCOS-driven hyperandrogenism is present in Ossabaw swine, similar to humans. (Support: NIH RR13223, HL62552, and ADA to M.S.).