Influence Of Prolacti、Estrogen And Insulin On Leptin And Its Receptor Of Mammary Epithelial Cells In Dairy Cow

Lactation of mammary glands is the result of co-regulated by mammogenesis and hormones. Hormones play an important role in the process of lactation. In order to understand the relation of leptin and exogenous hormones and research the new way, techniques and method of artificial control milk yield and qualitative, and provide the rationale and test foundation, in this experiment, Holstein cows were used as materials, cow mammary epithelial cells were cultured in vitro and treated with prolactin, estrogen and insulin. Then leptin and its acceptor expressed by those cells and the change of lactation of those cells were observed and analyzed by laser scanning confocal microscopy, Western bloting and Real-Time PCR.Result of this research indicated, the cow mammary epithelial cell of lactation period can be obtained by tissue cultivation.The observe result of laser scanning confocal microscopy indicated, the expression of leptin and its acceptor were located on mammary epithelial cell, extracellular matrix and the membrane of mammary epithelial cell respectively. The result of Western bloting analysis indicated, when cow mammary gland epithelial cells were treated with prolactin and estrogen, the expression of leptin and its acceptor by these cells were rose significant (P<0.05), but not changes (P>0.05) when treat insulin. The result of fluorescent quantitation Real-Time PCR indicated, the expression of mRNA of leptin and its acceptor in cow mammary epithelial cells were rose significant (P<0.05) when these cells were treated with prolactin and estrogen, but no changes (P>0.05) was occurred when these cells were treated with insulin. This result was consistent with the result of Western bloting analysis. The secretion of lactose, β-casein and triglyceride by cow mammary epithelial cell treated with prolactin, estrogen and insulin respectively were tested by high efficiency liquid chromatography and triglyceride kit respectively, the results indicated, the secretion of lactose by cow mammary epithelial cell were rose significant (P<0.05) when the cells were treated with prolactin, but no changes (P>0.05) when treat estrogen and insulin.The secretion of β-casein by cow mammary gland epithelial cell were rose significant (P<0.05) when the cells were treated with prolactin, estrogen and insulin. The secretion of triglyceride by cow mammary epithelial cell were no changes (P>0.05) in all three treatment groups.