Apoptosis In Mouse Mammary Gland And Impact Of Leptin On It

Apoptosis was programmed cell death process. In apoptosis, the tissue which was hurt or not required occurred programmed cell death. It was also to say that apoptosis was normal cell death and it was a physiology process against proliferation. In mammary gland development, proliferation and apoptosis were in balance. Research about apoptosis was one of the most important place and the mechanism about mammary gland cell apoptosis could help to reveal the regularity of mammary gland development.In these experiments, TUNEL and capillary electrophoresis were used to research the apoptosis of mammary gland in development. The results showed that apoptosis was associated with structure and function change in development of mammary gland. In virgin, mammary gland develop slowly and there was little changes in mammary gland. At this time ,there was little apoptosis in mammary gland cells. In virgin 50～60d, with the development of duct, apoptosis occurred in adipocyte increased. In pregnancy, adipocyte apoptosis increased greatly. In late pregnancy, there were a lot of gland alveolus and adipocyte disappeared because of apoptosis. In lactation, there was little changes in mammary gland structure, apoptosis level was low. In involution, gland alveolus collapsed and a lot of cells were apoptosis. In involution 3d, the apoptosis was highest then decreased. At this time, adipocyte in mammary gland increased and occupied the place where the apoptosis was existed. In involution 10d, the mammary gland was recovered and apoptosis decreased.The result of capillary electrophoresis was similar with the results of TUNEL. The results of capillary electrophoresis showed that the apoptosis of mammary gland were low and increased in involution. In involution 3d, the apoptosis of mammary gland was highest then decreased. This experiment also suggested that capillary electrophoresis was a convenience, quickly and high sensitivity method to detect apoptosis.Leptin was a cytocine which was synthesized and secreted by mammary gland. It was expressed in mammary fat pad and mammary epithelial cells. It suggested that it could control the development, lactation and involution of mammary gland. In this experiment, explants about involution 1d was cultured in vitro to investigate the impact of leptin on mammary gland apoptosis by TUNEL. The results showed that the structure of mammary gland without leptin keep normal and there were little apoptosis cells in them. But in explants with leptin, the duct and gland alveolus collapsed and the apoptosis cells increased. It showed that leptin induced mammary gland apoptosis...