흰쥐 생식소에서 GnRH-like mRNA의 발현과 세포내 분포

Expression and Cellular Localization of Gonadotropin-Releasing Hormone (GnRH)-like Messenger Ribonucleic Acid in the Rat Gonad

  • Park, Wan-Sung (Department of Anatomy, Gyungsang National University) ;
  • Lee, Sung-Ho (Department of Zoology, Seoul National University) ;
  • Kim, Hyun-Sup (Department of Zoology, Seoul National University) ;
  • Cho, Sa-Sun (Department of Anatomy, Seoul National University) ;
  • Young Namkung (Department of Biology, Kang Reung College) ;
  • Yoon, Yong-Dal (Department of Biology, Hanyang University) ;
  • Paik, Sang-Ho (Department of Anatomy, Seoulnational University) ;
  • Cho, Wan-Kyoo (Department of Zoology, Seoul National University) ;
  • Kim, Kyungjin (Department of Zoology, Seoul National University)
  • 발행 : 1990.10.01

초록

시상하부에서 합성, 분비되는 gonadotropin releasing horrnone (GnRH)의 면역반응성이 생식소를 비롯한 여러 부위에서도 검출됨이 알려졌으나, 이 펩타이트가 과연 생식소에서 국부적으로 합성되는 지에 관해서는 아직 밝혀지지 않았다. 본 연구에서는 흰쥐 생식소에서 GnRH유전자발현을 연구하기 위하여 GnRH-like mRNA와 GnRH펩타이트의 발현과 세포내 분포 양상을 조사하였다. GnRH 방사면역측정법과 GnRH를 크로마토그라피 방법으로 분리한 결과,시상하부에서 합성되는 GnRH와 유사한 GnRH 면역반은이 흰쥐 생식소 추출물에서 상당량 검출되었다. GnRH-면역반응이 흰쥐 난소의 다양한 세포군에서 나타냄에 반하여, GnRH-like mRNA는 granulsa,theca 그리고 luteal 세포에서만 주로 발현되었다. 또한 흰쥐 정소에서 GnRH면역반응성은 원시정세포, Sertoli,Leydig 세포에서만 검출된 반면에, GnRH-like mRNA는 정세관내의 Seertoli세포에서만 발현되었다. 따라서 이 연구는 생식소에 존재하는 GnRH는 생식소 내에서 국부적으로 합성, 발현되는 결과라고 사료되며, 생식소 내에서 생성된 GnRH는 생식소내 세포군간의 정보교환의 매개자로서 역활을 수행하고 있다고 추정된다.

Gonadotropin releasing horrnone (GnRH) is known to be extrahypothalamically localized with a broad range including gonad. It remains, however, unknown whether GnRH is locally synthesized in the gonad. The present srudy aims to identity expression and cellular localization of GnRH-Iike mRNA and immunoreactive GnRH in the rat gonad. GnRH radioimmunoassay and chromatographic extracts on G-50 sephadex column showed that rat gonadal extracts contained a substantial amount of immunoreactive GnRH similar to the hypothalamic and synthetic GnRH. Although a wide distribution of immunostainable GnRH-like molecule with different cell types in the rat ovary was observed, the major cell population hybridized with GnRH probe appears to be granulosa. theca cells and corpus luteum. Immunoreactive GnRH-Iike peptides were distributed m various regions of testis, including spermatogenic cells, Sertoli cells and Leydig cells. In situ hybridization revealed that positive signals of GnRH-Iike mRNA were predominandy present in Sertoli cells within some seminiferous tubules, but absent in the outside of seminiferous tubules in the testis. This study clearly demonstrated that GnRH-Iike molecule present in the rat gonad may be resulted from the local synthetic machinery of GnRH supporting the notion that this peptide may act as autocrine and/or paracrine role in intra-gonadal communication.

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