Cellular and molecular impact of exercise training on liver lipid infiltration

我们下一个研究计划的主要目标是了解在营养条件下(西方人的高脂肪饮食)和绝经后肝脏如何被脂肪渗透。我们还试图了解定期体育锻炼是如何与这些影响相违背的。有三种方法是我们优先考虑的。我们首先从分子基础上了解在高脂饮食和停用雌激素后，肝脏中新脂质的合成和氧化是如何分别被刺激和减少的。在第二种方法中，我们也有兴趣测试与肝脏输出脂质有关的特定假说。这是一个重要的考虑因素，因为它决定了循环中的血脂。在第三步中，我们感兴趣的是评估雌激素减少(即绝经)对涉及从心脏释放的催产素激素和心钠素的特定途径的影响。我们推测这两种激素对肝脏有保护作用。停用雌激素会减少这一途径的作用，并导致炎症等有害影响。总体而言，我们的下一个研究计划应该会带来新的信息，即富含脂肪的饮食如何导致脂肪在肝脏中积累，以及雌激素的退出如何以及为什么会导致脂肪在肝脏中的渗透，就像绝经后的女性所看到的那样。

Our main objective for our next research program is to understand how the liver gets infiltrated with fat under nutritional circumstances (westerner high-fat diet) and after menopause. We also try to understand how regular physical exercise contravenes these effects. There are three approaches that we privilege. We are first interested in understanding on a molecular basis how the synthesis of new lipids and its oxidation are respectively stimulated and reduced in liver under high-fat diets and following withdrawal of estrogens in rats. We are also interested, in a second approach, in testing specific hypotheses related to exportation of lipids from the liver. This is an important consideration since it determines circulating blood lipids. In a third step, we are interested in evaluating the impact of a reduction in estrogens (i.e. menopause) on a specific pathway involving oxytocin hormone and atrial natriuretic peptide liberated from the heart. We postulate that these two hormones have a protective effect on the liver. Withdrawal of estrogens will reduce the action of this pathway and causes deleterious effects such as inflammation. On the whole, our next research program should lead to new information regarding how diets enriched in fat leads to accumulation of fat in liver and how and why withdrawal of estrogens, as seen in post-menopausal women, also leads to infiltration of lipids in liver.