^13C-美沙西丁呼气试验定量评估非酒精性脂肪肝肝贮备功能

目的探讨^13C-美沙西丁呼气试验定量评估非酒精性脂肪肝肝细胞损害程度的方法及意义。方法雄性Wistar大鼠24只随机分为对照组（普通饮食）和模型组（高脂饮食），分别于8和12周末对两组大鼠进行^13C-美沙西丁呼气试验检测，观察呼气峰值（DOB）、达峰时间（T）、达峰高度和60min累积呼气量（CUM_60min）各参数的动态变化；处死动物，测门静脉、腹主动脉血中内毒素（ET）水平；取肝标本做HE染色，观察其病理变化。结果8周模型组呼气试验参数与同期对照组比较无统计学意义；12周模型组DOB、CUM_60min和达峰高度与同期对照组比较差异有统计学意义（P〈0．01），T较对照组前移，但差异无统计学意义（P〉O．05）。呼气试验结果与肝脏HE染色病变一致。8周、12周模型组门静脉ET水平较同期对照组明显上升，差异有统计学意义（P〈0．01）。腹主动脉与相应门静脉ET水平比较差异有统计学意义（P〈0．01）。门静脉ET水平与DOB、呼气试验丰度和CUM_60min呈正相关（P〈0．05）。结论^13C-关沙西丁呼气试验有可能成为一种非酒精性脂肪肝肝细胞功能的无创性评价方法。

13C-methacetin breath test as a quantitative liver function assessment in non-alcoholic fatty liver

Objective To investigate and assess 13C-methacetin breath test as a method to quantitatively evaluate the liver function of non-alcoholic fatty liver. Methods Twenty-four male Wistar rats were randomly divided into the following 2 groups, control group given a standard chow and model group given high-fat diet (88 % standard chow + 10% lard +2% cholesterol). At the 8th week and 12th week, the isotope-selective nondispersive infrared spectrometer (NDIRS) was applied to 13C-methacetin breath test. Peak value of breathing (DOB), the duration to peak (T), and cumulative expiration within 60 min (CUM60min) were determined. Then, the two groups of rats were executed respectively. The level of endotoxin in the portal vein and abdominal aorta was detected respectively, and the specific tissue of liver was fixed in 10% buffered formalin, processed, and embedded in paraffin for hematoxylin eosin (H&E). Results Compared with the control group, DOB increased in the model group at the 12th week but not at the 8th week. The trend was corresponded to the degree of path-ological lesion in the liver of rats. At the 8th week and 12th week, endotoxin levels in the portal vein of model group were significantly in-creased compared with control group. The breath test results were positively related to emlotoxin levels in the portal vein. Conclusion 13C-methacetin breath test may be a non-invasive method to evaluate the pathological changes of non-alcoholic fatty liver.