Long-term intermittent cold exposure affects peri-ovarian adipose tissue and ovarian microenvironment in rats

Abstract

Background: This study aimed to investigate the effects of cold exposure on peri-ovarian adipose tissue (POAT) and the relationship between POAT changes and ovarian function, to gain a deeper understanding of the mechanisms associated with cold exposure-induced changes in female reproductive health. Methods: Twenty female rats with regular estrus cycles were randomly divided into two groups: (1) the cold exposure group, which was exposed to –10°C, for 4 hours/day, for two weeks, and (2) the control group, which was maintained at 23 ± 1°C. Results: Cold exposure can increase serum E2 and FSH levels, and reduce AMH hormone levels, and cause the numbers of primary and secondary follicles in the cold-exposed group were significantly higher than those in the control group. Meanwhile, cold-stress-induced browning-related genes, including UCP1, PGC -1a, PRDM16, Fndc5 were upregulated in POAT, and the number of mitochondria in the cold-exposed group was significantly increased. Under cold exposure, the level of adipokines, including APDN, Lep, AMPK were significantly upregulated in POAT. FST was also upregulated in POAT, whereas MST, an AMPK inhibitor, was downregulated. The E2 synthesis rate-limiting-enzymes Cyplla1 and Cyp19 were upregulated in POAT. Conclusion: Cold exposure caused abnormal follicle development and promoted the browning of POAT. POAT browning was accompanied by the activation of the AMPK-PGC1α-Fndc5 pathway.

Does the ovarian surface epithelium differentiate into primordial follicle and primary follicle precursor structures?

“…Bu fibröz kılıf ovaryumun çevresindeki adipoz doku (peri-overyan adipoz doku) ile ovaryum yüzey epiteli arasında bulunmaktadır. Yapılan araştırmalarda peri-overyan adipoz dokunun ovaryumdaki folikülerin gelişimlerini sağladığı bildirilmiş ve bu dokunun ovaryumun fonksiyonları için önemli olduğu gösterilmiştir [34][35][36] .…”