Different Susceptibility To Liver Steatosis Induced By Overfeeding And Expression Of The Related Genes Regulating Hepatic VLDL-TAG Assembly And Secretion In Geese

Hepatic steatosis results from the excessive accumulation of triglyerides(TAG) within the animal's liver. And a number of studies have showed that inhibition of VLDL TG assembly and secretion is important one of causes of steatosis in Animal Models. The valued "fatty liver" is produced through the liver steatosis induced by overfeeding with a carbohydrate-rich corn-based diet in geese or ducks. But the mechanism of different susceptibility to liver steatosis and peripheral adipose storage still remains puzzling. In this study, susceptibility to fatty liver was studied in Landes and Sichuan White geese, which are hyper and hyporesponsive, respectively, to overfeeding. And related genes expression were studied on regulating VLDL TG production and secretion. The main results are listed as follows:1. Overfeeding was carried out by providing Landes and Sichuan White geese with amounts of food in proportion to their body weight. After two weeks of overfeeding, TAG content exceeded 90% in the animals' liver lipids, and the ratio of liver to body weight and percentage of liver lipids in Landes were markedly higher than those in Sichuan White geese(the ratio of liver to body weight: 8.55% VS 6.07% ; the percentage of liver lipids : 46.87% VS 38.47%). On the contraty, overfeeding led to lower increasement in the proportion of abdominal and subcutaneous adipose tissues from Landes than from Sichuan White geese. These data suggested that Landes had a better potential to use the massive amount of ingested food and to store lipids preferentially in the liver ; the Sichuan White geese showed a better distribution of lipids between liver and peripheral adipose tissues, and the lipid storage was more efficient in the adipose tissues in this genotype of geese.2.At the end of overfeeding, the plasma VLDL and TAG concentrations of Landes and Sichuan White geese were 100% higher than those of the control groups.The plasma VLDL concentration was significantly greater in Sichuan White geese than in the Landes geese. And The plasma VLDL concentration was positively correlated with fatty liver weight in Sichuan White geese, but not so in the Landes geese. This positive correlation indicated that the plasma VLDL concentration was a good indicator of hepatic lipogenesis, and suggested a relatively good balance between hepatic lipogenesis and lipoprotein...