高脂饮食豚鼠高密度脂蛋白代谢的特点

目的研究豚鼠高脂饮食后高密度脂蛋白代谢的特点,并与大鼠进行比较。方法将豚鼠和大鼠分别随机分为正常组（NC）和高脂组（HF）,正常组均给予普通饲料,高脂组给予高脂饲料诱导10周后,测定血清LDL-C、HDL-C水平,HDL3/HDL2比值和LCAT、CETP的表达;采用real-time RT-PCR方法检测肝脏SR-BI表达的变化。结果与正常组相比,豚鼠高脂组血清HDL-C水平显著升高,高密度脂蛋白亚型HDL3/HDL2的比值升高,血清CETP表达均显著增加,血清LCAT表达下降,肝脏SR-BI mRNA表达水平是正常组的2.27倍。而相同高脂饲料条件下,大鼠的上述指标均无明显变化。结论豚鼠摄入高脂饮食后HDL代谢与大鼠有所不同,主要表现为血清HDL-C升高,肝脏SR-BI受体表达增加,高密度脂蛋白亚型组分发生变化,大颗粒HDL2含量相对减少,小颗粒HDL3堆积,其机制与血清CETP、LCAT的变化密切相关。

Characteristics of High Density Lipoprotein Metabolism in High Fat Diet-Fed Guinea Pigs

Objective To study the characteristics of high density lipoprotein metabolism in guinea pigs fed with high fat diet,and compared with that in rats.Methods Healthy adult male guinea pigs and rats were randomly divided into normal control groups（NC） and high-fat groups（HF）（n = 10）,10 animals each,respectively.The NC groups were fed with normal forage,while the HF groups were given high fat diet（common forage plus 0.5% cholesterol and 10% lard） for 10 weeks.Blood samples were collected and the serum LDL-C,HDL-C levels,HDL3 /HDL2 ratio and CETP,LCAT concentrations were measured.The the hepatic relative expression of SR-BI mRNA was detected by real-time PCR.Results Compared with the control group,the serum HDL-C level,HDL3 /HDL2 ratio and CETP concentration in the guinea pigs of high-fat group were elevated significantly,LCAT was decreased（P 0.05）,and the relative expression of hepatic SR-BI mRNA was 2.27 times high as that of the control group（P 0.01）.However,there were no significant differences between those indexes in the rats of control and high-fat groups.Conclusion There are distinct differences in HDL metabolism between guinea pigs and rats when fed with high-fat diet.The serum HDL-C level and the expression of hepatic SR-BI are increased,the HDL subclasses are changed with a relative decrease of large-sized HDL2 particles and accumulation of small-sized HDL3 in the guinea pig,and its mechanisms are closely related to the changes of serum CETP and LCAT concentration.