Kashyap M L, Srivastava L S, Chen C Y, Perisutti C G, Campbell M, Lutmer R F, Glueck C J
J Clin Invest. 1977 Jul;60(1):171-80. doi: 10.1172/JCI108753.
A specific, precise, and sensitive double-antibody radioimmunoassay for the measurement of human apolipoprotein CII (apoCII) was developed. ApoCII was labeled with (125)I (chloramine-T) and monospecific antibody was raised in rabbits. No appreciable cross-reactivity with apolipoproteins CI, CIII, AI, AII, low density lipoproteins, and lipoprotein-free plasma was observed. Lipoproteins containing apoCII displaced the standard curve in parallel. ApoCII measurement was not affected by pretreatment of plasma with tetramethylurea, ethanol-diethyl ether, or heating. Mean (+/-SE) plasma-immunoreactive apoCII in 47 normotriglyceridemic subjects was 51.8+/-3.2 mug/ml, generally comparable with previous estimates of its concentration by other methods. ApoCII levels in 9 subjects with type IIB lipoprotein pattern, 14 with the type IV lipoprotein pattern, and 5 with type V lipoprotein pattern were respectively, 89.9+/-4.6, 85.4+/-6.9, 132.8+/-21.0 mug/ml, all higher than normals (P < 0.001). Plasma apoCII and triglyceride concentrations correlated in normo- and hypertriglyceridemics (r = 0.36 and 0.58, P < 0.05). Plasma triglycerides correlated inversely with the fraction of total apoCII in very low density lipoprotein (VLDL)-free plasma (r = -0.75, P < 0.01). There was no correlation between plasma apoCII and high density lipoprotein cholesterol. In normotriglyceridemics, VLDL apoCII levels correlated with in vitro lipoprotein lipase (LPL) activator activities (r = 0.89, P < 0.01). In hypertriglyceridemic subjects the mean concentrations of apoCII per milligrams VLDL protein, LPL activator activity per milligrams VLDL protein, and LPL activator activity per micrograms VLDL apoCII were all lower than in normotriglyceridemics, P < 0.05. As plasma triglycerides and apoCII increase, apoCII is redistributed from high density lipoprotein to VLDL. However, the amount of apoCII per milligram VLDL protein and its LPL activator potency per milligram VLDL protein are reduced. These factors may contribute to impaired VLDL catabolism.
已开发出一种用于测定人载脂蛋白CII（apoCII）的特异性、精确且灵敏的双抗体放射免疫测定法。用（125）I（氯胺-T）标记apoCII，并在兔体内制备单特异性抗体。未观察到与载脂蛋白CI、CIII、AI、AII、低密度脂蛋白和无脂蛋白血浆有明显交叉反应。含apoCII的脂蛋白使标准曲线平行位移。用四甲基脲、乙醇-乙醚预处理血浆或加热对apoCII测定无影响。47名正常甘油三酯血症受试者的血浆免疫反应性apoCII平均（±标准误）为51.8±3.2μg/ml，一般与先前用其他方法对其浓度的估计值相当。9名IIB型脂蛋白模式受试者、14名IV型脂蛋白模式受试者和5名V型脂蛋白模式受试者的apoCII水平分别为89.9±4.6、85.4±6.9、132.8±21.0μg/ml，均高于正常水平（P<0.001）。正常甘油三酯血症和高甘油三酯血症患者的血浆apoCII与甘油三酯浓度相关（r = 0.36和0.58，P<0.05）。血浆甘油三酯与极低密度脂蛋白（VLDL）-无血浆中总apoCII的比例呈负相关（r = -0.75，P<0.01）。血浆apoCII与高密度脂蛋白胆固醇之间无相关性。在正常甘油三酯血症患者中，VLDL apoCII水平与体外脂蛋白脂肪酶（LPL）激活剂活性相关（r = 0.89，P<0.01）。在高甘油三酯血症患者中，每毫克VLDL蛋白的apoCII平均浓度、每毫克VLDL蛋白的LPL激活剂活性以及每微克VLDL apoCII的LPL激活剂活性均低于正常甘油三酯血症患者，P<0.05。随着血浆甘油三酯和apoCII升高，apoCII从高密度脂蛋白重新分布到VLDL。然而，每毫克VLDL蛋白的apoCII量及其每毫克VLDL蛋白的LPL激活剂效力降低。这些因素可能导致VLDL分解代谢受损。
