实验性兔脂肪肝肝脂酶活性变化及茶多酚的作用

目的 观察肝组织中肝脂酶(HL)活性变化与肝细胞脂肪变性的关系,探讨茶多酚对HL活性变化的影响及机制。 方法 雄性新西兰白兔分为三组:脂肪肝组6只喂高脂饲料;茶多酚组7只喂高脂饲料,同时口服茶多酚200μg·g-1·d-1;正常对照组6只喂普通兔饲料。实验8周后测定血脂水平、血浆HL活性水平,肝组织做病理形态学检查同时用吐温法行HL活性染色,用硫代巴比妥酸比色法测定肝组织丙二醛(MDA)含量。 结果 脂肪肝组均产生重度混合型脂肪肝,血总胆固醇(TC)为(28.49±5.99)mmol/L,正常对照组为(1.11±0.82)mmol/L,t=21.654,P<0.05;血清低密度脂蛋白胆固醇(LDL-c)为(12.15±1.95)mmol/L,正常对照组为(0.71±1.14)mmol/L,t=12.400,P<0.05;肝组织MDA含量为(75.58±29.88)nmol/mg,正常对照组为(43.64±16.95)nmol/mg,t-2.278,P<0.05。每100μm2肝组织中HL活性点个数为1.76±0.10,正常对照组为4.14±0.05,t=3.306,P<0.05。茶多酚组:肝脏病理改变5只兔为中度混合型脂肪肝,2只兔为轻度混合型脂肪肝,明显轻于脂肪肝组。血TC为(16.87±6.58)mmol/L,明显低于脂肪肝组高于正常对照组(t值分别为5.786和3.968,P<0.05)。血LDL-c为(5.10±4.19)mmol/L,明显低于脂肪肝组(t=2.478,P<0.05)高于正常对照组(t=3.7634,P<0.05)。肝组织MDA含

Effects of tea polyphennols on hepatic lipase activity in rabbits with fatty liver

OBJECTIVE: To investigate the relationship between hepatic lipase activity and fatty degeneration of hepatocytes and explore the effects of tea polyphennols (TP) on the changes of hepatic lipase (HL) activity in rabbits with fatty liver. METHODS: According to serum cholesterol and triglyceride (TC) levels, 19 rabbits were divided into fatty liver group (FL, n=6) fed with high cholesterol diet, TP group (n=7) fed with high cholesterol diet and 20mug/g/d tea polyphennols everyday orally, control group (n=6) fed with normal diet. After 8 weeks, the levels of serum TC, HL activity, HL activity and malondildehyde (MDA) in hepatic tissue were detected, and the pathomorphology of hepatic tissue were determined in all rabbits. RESULTS: The fatty degeneration of hepatocyts in FL group was more severe than that in TP and control group. The serum TC level in TP group (16.87 6.58) mmol/L was higher than that (1.11 0.82) mmol/L in control group (t=5.786, p<0.05), but lower than that (28.49 5.99) mmol/L in FL group (t=3.968, p<0.05). The serum low density lipoprotein-cholesterol level in Tp group (5.10 4.19) mmol/L also higher than that (0.71 1.14) mmol/L in control group (t=3.763, p<0.05), but lower than that (12.15 1.95) mmol/L in FL group (t=2.478, p<0.05). The number of positive dots presenting HL activity level in 100 square micron, hepatic tissue in TP group (3.24 0.17) was higher than that (1.76 0.10) in FL group (t=-3.153, p<0.05), but lower than that (4.14 0.05) in control group (t=-2.902, p<0.05). The levels of MDA in hepatic tissue in TP group (44.66 26.18) nmol/mg was significantly lower than that (75.58 29.88) nmol/mg in FL group (t=2.261, p<0.05), but no evidently different from that (43.64 16.95) nmol/mg in control group. The plasma HL activity was no difference among the three groups. CONCLUSION: The HL activity in hepatic tissue with fatty degeneration of hepatocytes was lower than that in normal liver. Tea polyphennols can increase HL activity in hepatic tissue and protect hepatocytes from fatty degeneration.