Soler-Argilaga C, Infante R, Polonovski J
J Lipid Res. 1975 Mar;16(2):116-22.
The uptakes of albumin-bound nonesterified fatty acids and of [1-14C]palmitic acid complexed to albumin by the isolated perfused rat liver were compared. During perfusion, the rate of uptake of nonesterified fatty acids decreased and became zero when the fatty acid:albumin molar ratio reached 0.3, but the rate of uptake of radioactive palmitic acid remained constant. This finding suggests the existence of two pools of fatty acids bound to albumin with different fractional turnover rates. This view was supported by the fact that when delipidated albumin complexed in vitro to radioactive and nonradioactive fatty acids was used no difference was observed between the uptakes of nonesterified fatty acids and radioactive fatty acids by perfused liver. Similar results were found with albumin-bound radioactive fatty acid in vivo (obtained from rats fed radioactive palmitic acid), showing a homogeneous distribution of the label in both pools. The existence of two nonesterified fatty acid pools in plasma would arise from the differences in the nature of bonds between fatty acid and albumin molecules, which could determine the rate of exchange of fatty acids between the albumin-bound and soluble forms preceding their uptake by the cells.
比较了分离的灌注大鼠肝脏对白蛋白结合的非酯化脂肪酸和与白蛋白复合的[1-¹⁴C]棕榈酸的摄取情况。在灌注过程中，当脂肪酸与白蛋白的摩尔比达到0.3时，非酯化脂肪酸的摄取速率下降并变为零，但放射性棕榈酸的摄取速率保持恒定。这一发现表明存在两个与白蛋白结合的脂肪酸池，其分数周转率不同。当使用体外复合了放射性和非放射性脂肪酸的脱脂白蛋白时，灌注肝脏对非酯化脂肪酸和放射性脂肪酸的摄取没有差异，这一事实支持了这一观点。在体内用白蛋白结合的放射性脂肪酸（从喂食放射性棕榈酸的大鼠获得）也发现了类似结果，表明标记物在两个池中均匀分布。血浆中存在两个非酯化脂肪酸池可能是由于脂肪酸与白蛋白分子之间键的性质不同，这可能决定了脂肪酸在被细胞摄取之前在白蛋白结合形式和可溶性形式之间的交换速率。
