Toxalim (Research Centre in Food Toxicology), Université de Toulouse, INRAE, ENVT, UPS, 31300, Toulouse, France.
INP-ENSAT, Université de Toulouse, 31320, Castanet-Tolosan, France.
Sci Rep. 2023 Jan 19;13(1):1046. doi: 10.1038/s41598-022-27271-y.
Mule ducks have been force-fed to develop a hepatic steatosis, also called "foie gras", which is similar to the non-alcoholic fatty liver disease (NAFLD) described in humans and mammals. However, in hepatic steatosis resulting from force-feeding of ducks, very little is known about the fine biochemical events that occur due to the enormous and very rapid increase in total lipids that mainly accumulate in hepatocytes. To begin to reduce this lack of knowledge associated with the development of this specific hepatic steatosis, liver samples were taken at different times to follow the overall biochemical transformation of the liver as well as different markers of oxidative stress, hypoxia and apoptosis. The results indicate that the lipid content increases rapidly in the liver throughout the force-feeding period while the protein content decreases. The amount of hydroxyproline remains constant indicating that no liver fibrosis develops during the force-feeding period. On the contrary, all the tested biomarkers of cellular oxidative stress increase rapidly but without any visible disorder in the coordination of paired activities. At the same time, hypoxia-inducible factors also increase indicating that a hypoxia situation is gradually occurring in hepatocytes. This leads, in addition to the lipotoxicity induced by the accumulation of lipids, to an increased number of liver cells to enter into apoptosis. A relative variability in the level of these cellular responses was also observed indicating that, probably, certain animals support the development of this steatosis differently. This leads us to imagine that the physiological status of these birds may differ widely for reasons that remain to be clarified.
鹅肝是通过强制填饲鸭子来生产的，这种做法会导致肝脏脂肪沉积，这与人类和哺乳动物中描述的非酒精性脂肪肝（NAFLD）类似。然而，对于由于强制填饲而导致的脂肪肝，人们对由于总脂质大量且快速增加而导致的精细生化事件知之甚少，这些总脂质主要积聚在肝细胞中。为了开始减少与这种特定脂肪肝发展相关的这种知识缺乏，在不同时间采集肝样本来跟踪肝的整体生化转化以及氧化应激、缺氧和细胞凋亡的不同标志物。结果表明，在强制填饲期间，肝脏中的脂质含量迅速增加，而蛋白质含量减少。羟脯氨酸的含量保持不变，表明在强制填饲期间不会发生肝纤维化。相反，所有测试的细胞氧化应激生物标志物都迅速增加，但在配对活动的协调方面没有任何可见的紊乱。同时，缺氧诱导因子也增加，表明肝细胞中逐渐出现缺氧情况。除了脂质积累引起的脂毒性外，这还导致更多的肝细胞进入细胞凋亡。还观察到这些细胞反应水平的相对可变性，这表明，可能某些动物对这种脂肪肝的发展有不同的反应。这使我们联想到，这些鸟类的生理状态可能因尚未阐明的原因而存在很大差异。
