비만유전자 산물인 leptin은 지방 조직에서 생성되어 혈액으로 분비되며, 신진대사, 식욕, 체열 등을 조절하여 비만의 억제 조절 물질로 작용하는 것으로 알려져 있다. 또한 leptin은 비만 뿐만 아니라 생식 생리와도 관련이 있는 것으로 보이며, 이러한 leptin의 작용이 난소에 직접적인지 혹은 시상하부나 뇌하수체를 매개로 하는지는 아직 정확하게 밝혀지지 않고 있으며, 난소에서의 leptin 및 leptin 수용체의 발현 양상에 대한 연구 또한 미진
Leptin, the product of the obese gene, is produced by adipose tissue and is known to be a hormone concerned with regulation of appetite and metabolism. Recent reports have shown that leptin is associated not only with obesity but also with female reproduction, but it has not yet been ascertained whether leptin acts directly on the ovaries or indirectly via the hypothalamus or pituitary pathway. The object of this study is to determine the expression of leptin and its receptor in the ovaries of 3 and 8 weeks old rats by immunohistochemistry and RT-PCR. In the ovaries of 3 and 8 weeks old rats, leptin was stained in the theca cells and portions of granulosa cells of atretic follicles, whereas leptin receptors was stained in interstitial cells and ova of preantral follicles. The RT-PCR results showed that leptin receptor mRNA was expressed in the ovaries of both immature and adult rats, while leptin mRNA was not. In conclusion, leptin mRNA was not expressed in the ovaries, however, leptin was detected by immunohistochemistry. Compared to leptin itself, leptin receptors in the ovaries were ascertained by both RT-PCR and immunohistochemistry. These results suggest that leptin is related to the regulation of the physiological functions of the ovaries.