Dolphin P J, Stewart B, Amy R M, Russell J C
Biochim Biophys Acta. 1987 Jun 2;919(2):140-8. doi: 10.1016/0005-2760(87)90200-1.
The LA/N rat is one of two congenic strains bred from the original obese, hyperphagic and hypertensive rats of Koletsky. With the exception of hypertension the LA/N strain, when homozygous for the corpulent gene, is phenotypically similar to the parent Koletsky strain and prone to the development of vascular and myocardial lesions. Here we report a detailed analysis of the serum lipids, lipoproteins and apolipoproteins B, E and A-I levels in young adult homozygous corpulent (cp/cp) rats of both sexes and in lean males of the same age which were demonstrable non-carriers (+/+) of the cp gene. Both male and female cp/cp rats were hypertriglyceridemic (282-512 mg/100 ml) and moderately hypercholesterolemic (74-84 mg/100 ml). Elevations in these lipids reflected the presence of large (622 A), triacylglycerol-rich and apoprotein-poor VLDL containing both apolipoproteins Bh and B1 and increased phospholipid-rich HDL. Similar, but less pronounced, elevations in serum apolipoproteins B and E in the cp/cp rats when compared to the +/+ animals were also noted. Apolipoproteins A-I levels were 2.7-3-fold higher in cp/cp rats. The levels of VLDL were significantly higher in female cp/cp rats; however, the levels of IDL (intermediate-density lipoproteins), LDL and HDL were significantly lower than in the more atherosclerosis prone male cp/cp rats. Similarly, apolipoprotein A-I was higher and apolipoprotein B lower in the male cp/cp than in the female cp/cp rats. The LDL (d = 1.030-1.063 g/ml) in cp/cp rats, like that in normal animals, was heterogeneous and contained apolipoproteins Bh, E, A-I and C. This fraction was significantly elevated in male cp/cp rats when compared to females but still represented less than 13% of the total serum cholesterol and less than 6% of the total serum lipids in 3-month-old cp/cp animals. The ratio of cholesterol to phospholipids was significantly lower for all lipoproteins in cp/cp rats when compared to +/+ males and these ratios for female cp/cp rats were in all cases lower than those of male cp/cp animals.
LA/N大鼠是从科列茨基最初的肥胖、食欲亢进和高血压大鼠培育出的两种同源近交系之一。除高血压外，LA/N品系在纯合肥胖基因时，表型与亲代科列茨基品系相似，易于发生血管和心肌病变。在此，我们报告了对成年雌雄纯合肥胖（cp/cp）大鼠以及同龄纯合非肥胖基因携带者（+/+）雄性大鼠的血清脂质、脂蛋白以及载脂蛋白B、E和A-I水平的详细分析。雌雄cp/cp大鼠均有高甘油三酯血症（282 - 512毫克/100毫升）和中度高胆固醇血症（74 - 84毫克/100毫升）。这些脂质升高反映出存在大颗粒（622埃）、富含三酰甘油且载脂蛋白含量低的极低密度脂蛋白（VLDL），其同时含有载脂蛋白Bh和B1，以及富含磷脂的高密度脂蛋白（HDL）升高。与+/+动物相比，cp/cp大鼠血清载脂蛋白B和E也有类似但不太明显的升高。cp/cp大鼠的载脂蛋白A-I水平高出2.7 - 3倍。雌性cp/cp大鼠的极低密度脂蛋白水平显著更高；然而，中密度脂蛋白（IDL）、低密度脂蛋白（LDL）和高密度脂蛋白水平显著低于更易患动脉粥样硬化的雄性cp/cp大鼠。同样，雄性cp/cp大鼠的载脂蛋白A-I高于雌性cp/cp大鼠，而载脂蛋白B则低于雌性。cp/cp大鼠的低密度脂蛋白（密度 = 1.030 - 1.063克/毫升）与正常动物一样具有异质性，含有载脂蛋白Bh、E、A-I和C。与雌性相比，雄性cp/cp大鼠的这部分脂蛋白显著升高，但在3月龄cp/cp动物中仍占总血清胆固醇不到13%，占总血清脂质不到6%。与+/+雄性大鼠相比，cp/cp大鼠所有脂蛋白的胆固醇与磷脂比率显著更低，且雌性cp/cp大鼠在所有情况下该比率都低于雄性cp/cp动物。
