Rennick B R
Am J Physiol. 1981 Feb;240(2):F83-9. doi: 10.1152/ajprenal.1981.240.2.F83.
Transcellular active tubular transport of organic cations occurs in the proximal renal tubule in the direction of excretion. These organic cations may be primary, secondary, tertiary, or quaternary amines. Endogenous neurohumors such as choline and catecholamines and drugs such as morphine and tetraethylammonium are representative transportable organic cations. Competitive inhibition for transport is found among organic cations. Organic anions, however, do not compete for this transport. Organic cations used as drugs may interact with the transport of endogenous organic cations to alter the excretion patterns of both. Bidirectional active tubule transport can be demonstrated for choline and is accompanied by simultaneous renal metabolism of choline. Studies using vesicles prepared from luminal and antiluminal membranes of renal cortex suggest that organic cation transport occurs in both vesicle preparations. However, only the luminal vesicles showed the characteristics of carrier-mediated uphill transport.
有机阳离子的跨细胞主动肾小管转运发生在近端肾小管，且是朝着排泄方向进行的。这些有机阳离子可以是伯胺、仲胺、叔胺或季铵。内源性神经体液如胆碱和儿茶酚胺以及药物如吗啡和四乙铵都是具有代表性的可转运有机阳离子。在有机阳离子之间发现了转运的竞争性抑制。然而，有机阴离子并不竞争这种转运。用作药物的有机阳离子可能会与内源性有机阳离子的转运相互作用，从而改变两者的排泄模式。胆碱可表现出双向主动肾小管转运，且伴有胆碱的同时肾脏代谢。使用从肾皮质管腔膜和反管腔膜制备的囊泡进行的研究表明，有机阳离子转运在两种囊泡制剂中均会发生。然而，只有管腔囊泡显示出载体介导的上坡转运的特征。
