Remarkable features of ovarian morphology and reproductive hormones in insulin-resistant Zucker fatty (fa/fa) rats

Reproductive Biology and Endocrinology

Research

Yoshimitsu Kitajima¹  Hirofumi Henmi¹  Takashi Fujimoto¹  Kengo Manase¹  Shinichi Ishioka¹  Ayumi Shimizu¹  Eiki Ito¹  Hiroyuki Honnma¹  Toshiaki Endo¹  Tamotsu Kiya¹  Tsuyoshi Baba¹  Tsuyoshi Saito¹  Kunihiko Nagasawa¹ 

[1] Department of Obstetrics and Gynecology, Sapporo Medical University School of Medicine, South 1 West 16,Chuo-ku, 060-8543, Sapporo, Japan;

关键词: Granulosa Cell;    Adiponectin Level;    Estrous Cycle;    Serum Testosterone;    Theca Cell;   

DOI  :  10.1186/1477-7827-8-73

 received in 2010-01-13, accepted in 2010-06-24,  发布年份 2010

来源: Springer

【 摘 要 】

BackgroundZucker fatty (fa/fa) rats are a well-understood model of obesity and hyperinsulinemia. It is now thought that obesity/hyperinsulinemia is an important cause of endocrinological abnormality, but to date there have been no reports on the changes in ovarian morphology or the ovarian androgen profile in rat models of obesity and insulin resistance.MethodsIn this study we investigated the effects of obesity and hyperinsulinemia on ovarian morphology and the hormone profile in insulin-resistant Zucker fatty rats (5, 8, 12 and 16 weeks of age, n = 6-7).ResultsOvaries from 5-week-old fatty rats had significantly greater total and atretic follicle numbers, and higher atretic-to-total follicle ratios than those from lean rats. Ovaries from 12- and 16-week-old fatty rats showed interstitial cell hyperplasia and numerous cysts with features of advanced follicular atresia. In addition, serum testosterone and androstenedione levels significantly declined in fatty rats from age 8 to 16 weeks, so that fatty rats showed significantly lower levels of serum testosterone (12 and 16 weeks) and androstenedione (all weeks) than lean rats. This may reflect a reduction of androgen synthesis during follicular atresia. Serum adiponectin levels were high in immature fatty rats, and although the levels declined significantly as they matured, it remained significantly higher in fatty rats than in lean rats. On the other hand, levels of ovarian adiponectin and its receptors were significantly lower in mature fatty rats than in lean mature rats or immature fatty rats.ConclusionsOur findings indicate that ovarian morphology and hormone profiles are significantly altered by the continuous insulin resistance in Zucker fatty rats. Simultaneously, abrupt reductions in serum and ovarian adiponectin also likely contribute to the infertility seen in fatty rats.

【 授权许可】

Unknown   
© Honnma et al; licensee BioMed Central Ltd. 2010. This article is published under license to BioMed Central Ltd. This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.