Morpology Of Ovary And The Expression Of Ghrelin On Corpus Luteum In Pregnant Dairy Goats

To understand the periodic changes of corpus luteum of dairy dairy goat in different pregnant stages, and to know the corpus luteum constituent cells'cell type in different phages, the structure feature of different cell type, the cytological changes of different periods,The morphological structures and changes of goat ovaries from 4th to 21st weeks during pregnant stages were studied by using paraffin embedding and Hematoxinlin-Eosin staining method and transmission electron microscope techniques. The distribution discipline of ghrelin in goat corpus luteum during different stage of pregnancy were further studied by immunohistochemistry SP method to investigate both the regulation of ghrelin on ovrian function and its role on female reproduction based on analysis of ovarian reproductive physiological characteristics at corresponding stages. The results are as follow .1.The corpus luteum was surrounded by capsule of connective tissue which formed trabeculum by extending into parenchyma.The parenchyma was mainly composed of granulosa lutein cells(big lutein cells)and theca lutein cells(small lutein cells). The granulosa lutein cells which were in majority mainly located in the central area of corpus luteum. And, the theca lutein cells mainly located in the surrounding corpus luteum and diffusedly distributed among granulosa lutein cells. As the electron microscope results indicated, the typical difference between granulosa lutein cells(big lutein cells)and theca lutein cells(small lutein cells) is secretory granules and lipid droplet's distribution in the cytoplasmic. There are more the two substances exists in the big lutein cells than in the small lutein cells. The phenomenon of corpus luteum degradation exists in the whole pregnant stage,As the process of pregnancy, regressed luteal cells increased. The structural changes of luteal cells during regression were as follows:The cellular shape were changeable with strongly eosinophilic cytoplasm,condensed and fragmented nucleus. Under the electron microscope, the organelles of regressional lunteal cells denaturated,the amount of ntranuclear heterochromatin gradually increased, and nuclear membrane shrinkaged at later pregnant stage, Mitochondrial cristae were broken and fell of , the number of secretory granules decreased, Degradation aggregation of lipid droplet occurred, the amount of SER decreased or even disappeared , The number of cytoplasmic vacuoles increased, intercellular space increased. In the earlier pregnant stage, mid-pregnant stage and later pregnant stage, count the number of the growing ollicles and atretic follicle in the ovary, using the statistic method analyse it, the results show that growing ollicles in the earlier pregnant stage are most, decreased in the mid- pregnant stage, then in later pregnant stage, it began increased again, but the number of the atretic follicles was gradually decreased following the pregnant stage progress. The results showed that, the morphological structure of corpus luteum varied at different stages, and the number of degenerative luteal cells gradually increased; the corpus configuration in different pregnant stage can influent the number of growing ollicles and atretic follicle.2. Ghrelin positive reation were mainly present in capsule and luteal cells. The expression of ghrelin in capsule could be seen during whole pregnant stage with location of positive product on fibers and blood vessels. While ghrelin positive products in corpus luteum mainly located in large luteal cells with a trend increased firstly then reduced gradually at the angle of distribution range and staining intensity. It is suggested that, expression of ghrelin in corpus luteum were occurred at early pregnant stage, and with the process of embryonic development, the expression of ghrelin became increased, reached the highest in the medium term, then began decreased, in the 19 weeks reached the lowest by analysis of relative expression amount on ghrelin positive products in each-week corpus luteum of dairy goat. This kind of periodical expression of ghrelin in pregnant corpus luteum was adapted to its function. The results hinted that the expression of ghrelin was related to the function of corpus luteum.