Rebane E N, Kazbekov E N, Lyubimov Y a, Bulat M N
Sechenov Institute of Evolutionary Physiology and Biochemistry, Russian Academy of Sciences, St. Petersburg, Russia.
Membr Cell Biol. 1998;12(1):51-6.
The rates of p-aminohippurate (PAH) and of uric acid uptake by basolateral membrane vesicles isolated from proximal tubules of rat kidney have been investigated. Accumulation of both substrates against the concentration gradient within the vesicles was shown to occur in the presence of alpha-ketoglutarate (alpha-KG) and Na+ gradient in the incubation medium. The mechanism of the coupling between Na(+)-dicarboxylate symport and organic anion transport is discussed based on the differences between the rates of PAH and of uric acid uptake. It is proposed that the limiting step of coupling between two transporters is the step of alpha-KG-organic anion exchange.
对从大鼠肾脏近端小管分离出的基底外侧膜囊泡摄取对氨基马尿酸（PAH）和尿酸的速率进行了研究。在孵育介质中存在α-酮戊二酸（α-KG）和Na⁺梯度的情况下，两种底物均能逆着囊泡内的浓度梯度进行积累。基于PAH和尿酸摄取速率的差异，讨论了Na⁺-二羧酸盐共转运与有机阴离子转运之间的偶联机制。有人提出，两种转运体之间偶联的限速步骤是α-KG-有机阴离子交换步骤。
