Chiang A N, Chang C P, Chou Y C, Huang K Y, Hu H H
Institute of Biochemistry, National Yang-Ming University, Taipei, Taiwan.
J Hypertens. 1999 Jun;17(6):793-800. doi: 10.1097/00004872-199917060-00011.
To evaluate whether the differential distribution of apolipoprotein E among lipoprotein fractions and hepatic expression of the apolipoprotein E gene are causal factors in the regulation of lipid metabolism and physiological functions in young and aged spontaneously hypertensive and stroke-prone rats.
Biochemical analyses were performed on serum and hepatic specimens from young (2-month-old) and aged (8-month-old) spontaneously hypertensive rats, stroke-prone spontaneously hypertensive rats and normotensive Wistar-Kyoto rats. Levels of apolipoprotein E among various lipoprotein fractions were determined using sodium dodecyl sulfate-polyacrylamide gel electrophoresis. Liver concentrations of apolipoprotein E mRNA were analyzed by Northern blotting and relative levels of apolipoprotein E mRNA in different strains of rats were compared. Statistical analysis was performed by measuring correlations between hepatic apolipoprotein E mRNA levels and biological parameters.
Levels of apolipoprotein E in high-density and low-density lipoproteins were significantly lower in hypertensive rats than in age-matched normotensive Wistar- Kyoto rats. Although there was a significant increase in high-density lipoprotein apolipoprotein E contents in all aged animals, the elevation in aged hypertensive rats was much less than that in aged normotensive rats. Levels of apolipoprotein E in the very-low-density lipoprotein fraction were diminished in young stroke-prone rats but were remarkably high in aged rats. Steady-state levels of apolipoprotein E mRNA increased with age in all strains of rats, whereas aged hypertensive rats exhibited lower apolipoprotein E mRNA levels than aged normotensive rats.
The distribution of apolipoprotein E among various lipoprotein fractions was dramatically altered with age, and the alteration varied among different strains of rats. The differential distribution of apolipoprotein E in young and aged spontaneously hypertensive and stroke-prone rats suggests that apolipoprotein E could be a causal factor that disturbs the homeostasis of lipids and lipoproteins and perturbs physiological functions in hypertensive rats.
评估载脂蛋白E在脂蛋白组分中的差异分布以及载脂蛋白E基因的肝脏表达是否是年轻和老年自发性高血压及易卒中型大鼠脂质代谢和生理功能调节的因果因素。
对年轻（2个月大）和老年（8个月大）的自发性高血压大鼠、易卒中型自发性高血压大鼠和正常血压的Wistar-Kyoto大鼠的血清和肝脏标本进行生化分析。使用十二烷基硫酸钠-聚丙烯酰胺凝胶电泳测定各种脂蛋白组分中载脂蛋白E的水平。通过Northern印迹分析肝脏中载脂蛋白E mRNA的浓度，并比较不同品系大鼠中载脂蛋白E mRNA的相对水平。通过测量肝脏载脂蛋白E mRNA水平与生物学参数之间的相关性进行统计分析。
高血压大鼠高密度和低密度脂蛋白中的载脂蛋白E水平显著低于年龄匹配的正常血压Wistar-Kyoto大鼠。尽管所有老年动物的高密度脂蛋白载脂蛋白E含量均显著增加，但老年高血压大鼠的升高幅度远小于老年正常血压大鼠。极低密度脂蛋白组分中的载脂蛋白E水平在年轻易卒中型大鼠中降低，但在老年大鼠中显著升高。所有品系大鼠中载脂蛋白E mRNA的稳态水平均随年龄增加，而老年高血压大鼠的载脂蛋白E mRNA水平低于老年正常血压大鼠。
载脂蛋白E在各种脂蛋白组分中的分布随年龄显著改变，且这种改变在不同品系大鼠中有所不同。年轻和老年自发性高血压及易卒中型大鼠中载脂蛋白E的差异分布表明，载脂蛋白E可能是扰乱高血压大鼠脂质和脂蛋白稳态并干扰生理功能的因果因素。
