Study On Expression Of GnRH Receptor,5-HT Receptor In Pituitary And Serotonin 2C And Serotonin 6 Receptor In Hypothalamus Of Ovariectomied Rat

Hot flashes affect approximately 75% of postmenopausal women and are one of the most common health problems for this group.It had been found that relations exists between hot flashes and serotonin,hot flashes and catecholamine et al in experimental research of the pathophysiology of hot flashes. In recent years, the study on central nervous system especially body temperature regulating center becomes more and more wide,and many achievements have become true. But the pathophysiology of hot flashes remains unknown up to now,therefore limits valid control of hot flashes.In this study,we try to find some factors havingrelations with hot flashes by contructing animal model of hot flashes. According to physiological conditions of postmenopause of women, the rats were ovariectomined.We made vaginal smear from third day to ninth day after operation to determine the model was successful. Expression of GnRH receptors and 5-HT receptors in pituitary and 5-HT2c 5-HT6 receptors subtypes in hypothalamus were detected when the symptoms of hot flashes appears, in this way,we can understand the machnism of hot flashes deeply.一 Construction of hot flashes animal modelWe detected the rectal temperature of animal model by digital thermometer after ovariectomined. We made vaginal smear from third day to ninth day after operation to determine the model was successful.When the rectal temperature of animal model increase we begin to study.二 The expression of GnRH receptors and 5-HT receptors in pituitary and 5-HT2c 5-HT6 receptors subtypes in hypothalamus were detected by immunohistochemical staining Western blot, reverse transcription-po1ymerase chain reaction (RT-PCR) technique.三 Results as follows:1. Rectal temperature of rat appears higher from the eighth week after ovariectomined (p<0.05) ;2. The coexpression of GnRH receptors and 5-HT receptors were found in pituitary of two groups,and the expression of GnRH receptors and 5-HT receptors inexperimental group (201. 9±14. 3) (215. 4 ± 3. 1) is stronger obviously than that in control (240.2 ± 0.8) (252.6 ± 3. 7) (p<0.05) ;3. The results of Western blotconfirm the former results.4. The expression of 5-HT2C receptor subtype in rat hypothalamus in experimental group (72.3±2.9) % is stronger than that of control (37.9 ± 2.0) % , P<0. 05 ; While the expression of 5-HT6 receptor subtype have no difference between two groups (75.9 ± 2.7) % (77.4±3.1) %, P>0.05四. These results suggest that:1. Rectal temperature of rat appears higher from the eighth week after ovariectomined;2. The stronger expression of GnRH receptors and serotonin receptors in pituitary and 5-HT2C receptors subtype in hypothalamus may play a role in rectal temperature, but the expression of 5-HT6 receptors subtype in hypothalamus may have no role.3. It is concluded that the higher expression and coexpression in pituitary of GnRH receptors and serotonin receptors after rat ovariectomined may be related to pathogenesis of hot flushes.The changes of expression of 5-HT2C receptors subtype in hypothalamus may participate the pathogenesis of hot flahes.