Study On The Location And Expression Of Leptin Receptor In Small Tail Han Sheep

Leptin receptor was discovered as a leptin binding protein hormone in recent years, which had an important role in regulating the development of animals. In the present study, Einght old female Small Tail Han Sheep in good health were included. We investigated the location and expression of OB-R in neuroendocrine system (hypothalamus, pituitary), digestive system (abomasum, duodenum) and reproductive system (uterus and ovary) by convertional HE staining and Immunohistochemical methods. Whilst the expression and the types of isomer of OB-R were studied by Western blot method. The results showed that: (1) HE stain showed that the structures were clear in all the organizations and the figure of cells were intact. (2) It was found by Immunohistochemical method that OB-R protein was expressed in all the detected organs. The brown tan was mostly located in the cytoplasm.①There are large number of OB-R positive cells in Hypothalamus, and these neurons were fusiform, round or irregular shape. The nuclear was in the middle or close to one side of neuron;②Positive cells in the pituitary were largely located in pars distalis of adenohypophysis. The brown tan was located in the cytoplasma of Chromophils cells.③There was no obviously OB-R protein expression in muscularis and serosa of abomasum. Large amounts of OB-R positive cells were located in the gastric glands. The positive cells were large in size and the nuclear were round.④There were OB-R positive cells in the column epithelium and intestinal glands of the duodenum, and OB-R was not be found in the goblet cells.⑤In ovary, OB-R were expressed in the oocyte cytoplasm of different stage follicle. In the follicular cells of primordial follicle there was no OB-R protein. With the development of the follicle, OB-R positive protein was found in the granule cell of growth follicles.⑥O B-R protein was expressed in the columnar epithelial cells of uterus glands. The brown tan was located in the apex cytoplasm of the columnar epithelial cells. (3)Western blot experiments showed that OB-R was expressed in all the detected organs, and three bands were observed. The molecular mass of the three bands of OB-R were 120KDa, 110KDa and 98KDa.①In the neuroendocrine system, the three protein band were all observed in hypothalamus and pituitary. The protein in 120KDa was expressed weakly, and the intensity was similar in the two organs. The intensity was the most strong in 110KDa, and it is weak in 98 KDa.②In the digestive system: the protein in 120KDa and 110KDa were strong expressed in abomasums, and the expression of 98KDa protein band was weak. In duodenum the protein in 110KDa and 98KDa band were expressed strongly, and in120KDa was weak.③In the reproductive system, the protein intensity in 110KDa in uterus was much strong, and in 120KDa, 98KDa were weak; the three bands in 120KDa, 110KDa, 98KDa were expressed strongly in ovary. In conclude, OB-R protein was much strongly expressed in multi-organs. It was inferred that the leptin and the leptin receptor play an important role in the digestive and reproductive function in Small Tail Han Sheep.