动物造模 z-bo 2022-02-04 449

　　Previous studies have shown that weight gain will reduce the body's sensitivity to food taste, and the sense of smell can be restored with weight loss. However, the underlying mechanism has not been clear enough. Researchers from Cornell University found that the inflammatory response caused by obesity can reduce the number of taste buds on the tongue of mice.

　　Each taste bud contains about 50-100 cells, which are divided into three different types, each of which is responsible for different types of taste (sweet, sweet, bitter and salty). The life cycle of taste bud cells is only 10 days, and they can be replaced quickly. In order to study the effect of obesity on taste bud cells, the researchers gave mice a high-fat diet. The results showed that eating high-fat diets caused obesity in mice, which made the number of taste buds lower than control mice, while the distribution and size of different types of cells in each taste bud remained unchanged.

　　The regeneration of taste bud cells is mediated by programmed cell death, that is, apoptosis, and the differentiation of special taste bud precursor cells. However, the researchers found that the proportion of apoptosis in the taste buds of obese mice was higher, while the number of taste bud precursor cells decreased significantly, which revealed the reason for the decrease in the number of taste buds. Obesity-tolerant mice will not show the above symptoms after receiving high-fat diet, indicating that the accumulation of fat tissue, rather than ingestion, is the cause of the decrease in the number of taste buds.

　　Previous studies have shown that obesity is accompanied by chronic inflammation, which is due to the ability of adipose tissue to secrete pro-inflammatory factors. The authors believe that a high-fat diet will increase the secretion of TNF-a, and mice with restricted secretion of this factor will not experience a decrease in the number of taste buds. Conversely, injecting TNFa into the tongue can lead to a decrease in the number of taste buds without changing body weight.