Lapointe D S, Olson M S
Department of Biochemistry, University of Texas Health Science Center, San Antonio 78284-7760.
Hepatology. 1989 Feb;9(2):278-84. doi: 10.1002/hep.1840090220.
Mean transit times for the movement of extracellular and intracellular reference compounds through isolated perfused rat livers were determined during exposure of livers to platelet-activating factor (AGEPC; 1-O-hexadecyl-2-acetyl-sn-glycero-3-phosphocholine) and the alpha-adrenergic agonist phenylephrine, using the multiple indicator dilution technique. From the outflow profiles of rapid bolus injections of 3H-sucrose and 14C-urea given to the liver, the estimated intracellular volume of distribution of small freely permeant substances, Vi, and the ratio of intracellular to extracellular space, were computed. Exposure of the liver to AGEPC decreased Vi and by 32 and 34%, respectively, from control values, whereas infusion of phenylephrine increased Vi by 16% and by 33%. The results indicate that the hemodynamic effects of AGEPC in perfused rat liver cause the apparent loss of tissue space accessible to small permeant compounds. Phenylephrine, although increasing hepatic vascular resistance, measured at the portal vein, by the same magnitude as AGEPC, led to an increase in the apparent tissue space accessible to this same species.
在使用多指示剂稀释技术将肝脏暴露于血小板活化因子（AGEPC；1-O-十六烷基-2-乙酰基-sn-甘油-3-磷酸胆碱）和α-肾上腺素能激动剂去氧肾上腺素的过程中，测定了细胞外和细胞内参考化合物通过离体灌注大鼠肝脏的平均转运时间。根据快速推注给予肝脏的3H-蔗糖和14C-尿素的流出曲线，计算了小的自由通透物质在细胞内的分布容积Vi以及细胞内与细胞外空间的比率。将肝脏暴露于AGEPC会使Vi分别比对照值降低32%和34%，而输注去氧肾上腺素会使Vi增加16%和33%。结果表明，AGEPC对灌注大鼠肝脏的血流动力学作用导致小的通透化合物可及的组织空间明显减少。去氧肾上腺素虽然使在门静脉处测得的肝血管阻力增加的幅度与AGEPC相同，但却导致同一物质可及的表观组织空间增加。
