Study on the Cyclic Change of Leptin and Its Receptor Expression during the Estrous Cycle of Rat

흰쥐의 발정주기동안 난소내 Leptin 및 Leptin 수용체 발현의 주기적 변화에 관한 연구

  • 김명신 (서울여성병원 불임연구실) ;
  • 양현원 (을지의과대학교 생명과학연구소) ;
  • 권혁찬 (봄여성병원 산부인과) ;
  • 김세광 (연세대학교 산부인과학교실) ;
  • 조동체 (연세대학교 산부인과학교실) ;
  • 윤용달 (한양대학교 생명과학과)
  • Published : 2002.12.01

Abstract

Leptin, a product of the obese gene, is associated not only with obesity but also with female reproductive function, but it has not yet been ascertained whether leptin acts directly on the ovary or indirectly via the hypothalamus-pituitary pathway. Therefore, the object of this study was to investigate the expession of leptin and its receptor in the rat ovary by immunohistochemistry and RT-PCR during the estrous cycle. Immunohistochemistry results showed that leptin was stained in the theca cells and in part of granulosa cells in atretic follicles, whereas leptin receptor was localized in the interstitial cells and ova in preantral follicies. In particular, leptin and its receptor in atretic follicles displayed more intensive staining compared to those in normal follicles. During the estrous cycle, the mRNA expression of leptin and its receptor in the ovary was detected by RT-PCR and estradiol, progesterone, and leptin levels in the serum was measured by ELISA. The leptin level in the serum on metestrous phase was significantly higher than that on estrous phase. Similar to leptin level, progesterone level increased on metestrous phase. Leptin mRNA was not detected throughout the estrous cycle, whereas leptin receptor mRNA was expressed on all phases of estrous cycle excepting the diestrous phase. These results suggest that leptin might be directly involved in the regulation of ovarian function in rat.