Hoffman J S, Benditt E P
J Clin Invest. 1983 Apr;71(4):926-34. doi: 10.1172/jci110847.
The plasma clearance kinetics of the amyloid-related high density lipoprotein (HDL) apoprotein serum amyloid protein (apoSAA) was examined in BALB/c mice by two different methods, using labeled 125I-apoSAA-rich HDL and unlabeled plasma apoSAA (clearance monitored by radioimmunoassay). The plasma half-life of apoSAA, estimated by both methods, was on the order of 75-80 min, as compared with a value of approximately 11 h for mouse apoA-I. In trace-labeling studies, the rapid plasma clearance of both major 125I-labeled apoSAA isotypes was observed; this metabolic behavior was unique to these polypeptides among HDL apoproteins. The property of rapid plasma clearance was lost upon purification and reconstitution of 125I-apoSAA with HDL, indicating that this property is labile to denaturing conditions. Studies aimed at determining the metabolic fate of 125I-apoSAA gave no evidence for either the selective excretion of 125I-apoSAA or clearance to unique tissue sites as compared with other 125I-HDL apoproteins.
采用两种不同方法，利用标记的富含125I-血清淀粉样蛋白（apoSAA）的高密度脂蛋白（HDL）和未标记的血浆apoSAA（通过放射免疫测定法监测清除率），在BALB/c小鼠中检测了淀粉样相关高密度脂蛋白（HDL）载脂蛋白血清淀粉样蛋白（apoSAA）的血浆清除动力学。通过两种方法估算的apoSAA血浆半衰期约为75 - 80分钟，而小鼠载脂蛋白A-I（apoA-I）的血浆半衰期约为11小时。在微量标记研究中，观察到两种主要的125I标记的apoSAA同种型在血浆中快速清除；在HDL载脂蛋白中，这种代谢行为是这些多肽所特有的。在用HDL对125I-apoSAA进行纯化和重组后，快速血浆清除特性丧失，这表明该特性对变性条件不稳定。旨在确定125I-apoSAA代谢归宿的研究未发现与其他125I-HDL载脂蛋白相比，125I-apoSAA有选择性排泄或向特定组织部位清除的证据。
