Remodeling of mammary tissue and lactation persistency / Remodelage de la glande mammaire et persistance de la lactation

乳腺组织重塑和泌乳持久性 / Remodelage de la lande mammaire et persistance de la milkation

• 批准号: 249618-2012
• 负责人: Lacasse, Pierre
• 金额: $ 1.6万
• 依托单位: Université de Sherbrooke
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2015
• 资助国家: 加拿大
• 起止时间: 2015-01-01 至 2016-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=570662
• 关键词: Remodeling; mammary; tissue; lactation; persistency

The long range objectives of this research program are to improve our knowledge of the biological process involved in the control of mammary gland involution and to develop economically viable and consumer acceptable technologies or practices that would improve lactation persistency and enable longer lactation in dairy cows. Extended lactation would reduce the proportion of cow's lifetime spent in early lactation and, thus, the occurrence of disease, metabolic disorder and reproduction failure associated with this period. Apoptosis occurs in late lactation and accounts for the progressive loss of secretory cells in declining lactation. Therefore, there are considerable incentives to identify the factors which regulate mammary apoptosis. Recent work carried out in my laboratory, have shown that the hormone prolactin (PRL) is galactopoietic in dairy ruminants and a survival factor for mammary cells. Therefore, it is possible that PRL, especially the milking-induced PRL, is an important factor for lactation persistency by limiting the loss of cells and maintaining cell differentiation. We also found that the galactopoietic action of PRL is modulated at the level of the mammary gland. My hypotheses are: -It is possible to reduce the rate of decline in milk production by reducing the rate of mammary cell death; the milking-induce PRL release is important for the differentiation and the survival of the mammary cells and; several factors affect milk production and lactation persistency by modifying gland sensitivity to PRL. The short range objectives are: 1- To determine the factors controlling the milking-induced release of PRL. 2- To determine how sensitivity of the mammary gland to PRL is modulated. 3- To determine if factors that affects milk production affects also PRL secretion and/or sensitivity. 4- To determine the effect of the dry period on the mammary gland.

该研究计划的长期目标是提高我们对控制乳腺退化的生物过程的了解，并开发经济可行且消费者可接受的技术或实践，以提高泌乳持久性并延长奶牛的泌乳时间。延长泌乳期会减少奶牛一生中泌乳早期的比例，从而减少与这一时期相关的疾病、代谢紊乱和繁殖失败的发生。细胞凋亡发生在泌乳后期，是泌乳衰退过程中分泌细胞逐渐丧失的原因。因此，有相当大的动力去鉴定调节乳腺细胞凋亡的因素。 我的实验室最近进行的研究表明，催乳素 (PRL) 激素在乳反刍动物中具有泌乳素生成作用，并且是乳腺细胞的生存因子。因此，PRL，尤其是挤奶诱导的PRL，可能通过限制细胞损失和维持细胞分化而成为泌乳持续性的重要因素。我们还发现 PRL 的泌乳作用在乳腺水平上受到调节。 我的假设是： - 通过降低乳腺细胞死亡率来降低产奶量下降的速度是可能的；挤奶诱导的 PRL 释放对于乳腺细胞的分化和存活很重要；有几个因素通过改变腺体对 PRL 的敏感性来影响产奶量和泌乳持续性。 短期目标是： 1- 确定控制挤奶引起的 PRL 释放的因素。 2- 确定乳腺对 PRL 的敏感性是如何调节的。 3- 确定影响产奶量的因素是否也会影响 PRL 分泌和/或敏感性。 4- 确定干奶期对乳腺的影响。