Studies On The Molecular Mechanism Of Leptin's Action On The Hypothalamic-Pituitary-Gonadal Axis In Female Rats

The Female rats were employed in present study to investigate the molecular mechanism of Leptin' s action on the Hypothalamic-Pituitary-Gonadal Axis by nucleic acid hybridization in situ and relative quantitative RT-PCR.1. Studies on expression and localization of the long form Leptin Receptor mRNA in the hypothalamus, pituitary and ovary in RatTo examine the expression and localization of the long form Leptin Receptor mRNA in the hypothalamus, pituitary and ovary in 15 female Rats b> nucleic acid hybridization in situ. The result showed:Ob-Rb mRNA was located and expressed widely in the hypothalamus, and highly expressed in the nucleus arcuatus, the nucleus paraventricularis and periventricularis and dorsomedialis. The result was identical with the other studies and affirmed in advance the results of the other studies. But the result also showed the Ob-Rb mRNA was expressed highly in the nucleus dorsomedialis and the area hypothalamica lateralis of the hypothalamus. Our results remedied the distribution material of the long form Leptin Receptor in the hypothalamus in rat.Ob-Rb mRNA was distributed widely in the area of pituitary pars tuberalis, pars intermedia and pars nervosa. There are the snuff color grains of Ob-Rb mRNA in the acidophilic cell and basophilic cell of pituitary pars tuberalis. There are no the snuff color grains of Ob-Rb mRNA in the chromophobic cell of pituitary parstuberalis. There are the snuff color grains of Ob-Rb mRNA basophilic cell of pituitary pars intermedia. Aslo there are the snuff color grains of Ob-Rb mRNA in pituitary pars nervosa. But the snuff color grains of Ob-Rb mRNA focused around the cell of nerve twig, nerve fibre and capillary vessel. The result provided detailed information of the long form Leptin Receptor distribution in the pituitary of rat.Ob-Rb mRNA were mainly distributed in the corpus lateum cell and the grain cell around corpus lateum, primary follicles, growth follicles and mature follicles. The snuff color grains of Ob-Rb mRNA were distributed densely in the corpus lateum cell, but no distribution in the other position. The result provided detailed information of the long form Leptin Receptor distribution in the ovary of rat.Above the studies illustrated that the long form Leptin Receptor have had the physiological regulated action on the Hypothalamic-Pituitary-Gonadal axis in rat. Our results provided anatomic information to understand the physiology of Leptin and Leptin Receptor.2. Ration analyzing method of the results used by nucleic acid hybridization in situ and ration analyzing of the long form Leptin Receptor mRNA in the hypothalamus and pituitary of RatsExpression of the Long Form Leptin Receptor mRNA in the hypothalamus and pituitary of Rats was investigated by in situ hybridization. Rats were administrated with lug Leptin and lug Physiological Saline by lateral ventricle injection, and Integrated optical density of Ob-Rb mRNA was measured in order to compare with the intensity of leptin injection, Physiological Saline Injection and blank. The results showed that OB-Rb mRNA was expressed and located widely in the hypothalamus and pituitary of Rats. Expression level increased after Leptin injection (PO.01) in the hypothalamus and pituitary of Rats.Leptin can effect directly on the hypothalamus and pituitary of Rat, The intensity of Its role might be related with expression level of OB-Rb mRNA.993. Effects of Leptin on expression of hypothalamic POMC, NPY, GnRH, Ob-R mRNA and pituitary LH and GH mRNA in rats by lateral ventricle injectionTo explore the effects on expression of Hypothalamic POMC, NPY, GnRH, Ob-R mRNA and pituitary LH and GH mRNA in Rats by lateral ventricle injection.Fifteen female SD rats that its weight are 180 to 200 g were Selected, which were divided randomly into tree groups, namely Leptin injection group, Saline injection group and blank group. Expression levels of Hypothalamic POMC ,NPY, GnRH and OB-R mRNA and pituitary LH and GH mRNA was measured by a method of RT-PCR.The...