Removal of peri-ovarian adipose tissue affects follicular development and lipid metabolism

The development and maturity of follicles are regulated by sex hormones and growth factors. It has been proven that peri-ovarian adipose tissue (POAT) plays an important role in folliculogenesis and fertility in the female ICR and KM mice. The aim of the present study was to further investigate whether the removal of bilateral POAT affected follicular development and lipid metabolism in the female C57BL/6 J mice. Female C57BL/6 J mice at 6-week old were sham-operated (Sham) or removed bilateral POAT (Surgery). After 2 weeks, the mice were subjected to the body composition analysis and indirect calorimetry measurement. Our results show that the Surgery mice exhibited abnormal follicular development, including increased follicular dysplasia and atresia, decreased serum sex hormone levels, and abnormal expression of follicular development-related genes. Correspondingly, the endometrial thickness of the Surgery mice was less than the Sham mice. In addition, the Surgery mice had abnormal lipid metabolism, including reduced fat mass, increased energy expenditure, and up-regulated gene and protein expression involved in lipolysis. These data confirmed the importance of POAT in the follicular development in the female reproduction and suggested the contribution of POAT to the whole-body lipid metabolism. Summary Sentence Peri-ovarian adipose tissue plays a role in follicular development and lipid metabolism.