ObjectiveTo develop a new polycystic ovary syndrome (PCOS) rat model suitable for exercise intervention.MethodThirty six rats were randomly divided into three experimental groups: PCOS rats with high-fat diet (PF, n = 24), PCOS rats with ordinary diet (PO, n = 6), and control rats with ordinary diet (CO, n = 6). Two kinds of PCOS rat model were made by adjustment diet structure and testosterone injection for 28 days. After a successful animal model, PF model rats were randomly assigned to three groups: exercise with a continuation of high-fat diet (PF-EF, n = 6), sedentary with a continuation of high-fat diet (PF-SF, n = 6), exercise with an ordinary diet (PF-EO, n = 6). Fasting blood glucose (FBG) and insulin (FINS), estrogen (E2), progesterone (P), and testosterone (T) in serum were determined by RIA, and ovarian morphology was evaluated by Image-Pro plus 6.0.ResultsBody weight, Lee index, FINS increased significantly in PF rat model. Serum levels of E2 and T were significantly higher in PF and PO than in CO. Ovary organ index and ovarian areas were significant lower in PF than in CO. After intervention for 2 weeks, the levels of 1 h postprandial blood glucose (PBG1), 2 h postprandial blood glucose (PBG2), FINS and the serum levels of T decreased significantly in PF-EF rats and PF-EO rats. The ratio of FBG/FINS was significant higher in PF-EO rats than in PF-SF rats. Ovarian morphology showed that the numbers of preantral follicles and atretic follicles decreased significantly, and the numbers of antral follicles and corpora lutea increased significantly in the rats of PF-EF and PF-EO.ConclusionBy combination of high-fat diet and testosterone injection, the obese PCOS rat model is conformable with the lifestyle habits of fatty foods and insufficient exercise, and has metabolic and reproductive characteristics of human PCOS. This model can be applied to study exercise intervention.

Hyperandrogenism and hyperinsulinemia are major clinical features in women with polycystic ovary syndrome (PCOS). We hypothesized that serum insulin levels reduced by exercise could relieve hyperandrogenism and ameliorate polycystic ovarian morphology. Wistar female rats with 21-day-old were randomly divided into three groups: PCOS exercise (P-Ex), PCOS sedentary (P-Sed), and control sedentary (C-Sed). The rats with PCOS were induced by injection with testosterone propionate continuously. The exercise program was to swim with 120 min/d for two weeks. Fasting blood glucose (FBG) and insulin (FINS), estrogen (E (2)), progesterone (P), and testosterone (T) in serum were determined by RIA, and ovarian morphology was evaluated by Image-Pro Plus 6.0. The levels of FINS, E (2), and T in serum were significantly lower in P-Ex than in P-Sed. The ratios of FBG/FINS in P-Ex significantly increased in comparison with P-Sed. The levels of serum sex hormones in P-Ex were similar to C-Sed. There were no differences in blood glucose and serum progesterone among three groups. Ovarian morphology showed that the numbers of preantral follicles and atretic follicles significantly decreased, and the numbers of antral follicles and corpora lutea significantly increased in P-Ex compared with P-Sed. The changes of ovarian morphology in P-Ex were similar to C-Sed. These results demonstrated that short-term exercise training can improve insulin sensibility, decrease serum androgen levels, and recover normal ovarian morphology. The exercise training is the basic therapeutic means for PCOS.