Barac-Nieto M, Murer H, Kinne R
Pflugers Arch. 1982 Feb;392(4):366-71. doi: 10.1007/BF00581633.
The uptake of L(+)lactate into rat renal cortical brush border (BBV) and basolateral (BLV) membrane vesicles, isolated through differential centrifugation and free flow electrophoresis, were studied using a rapid filtration technique. In contrast to the lactate transport into the BBV, that into the BLV: 1) was found to proceed only towards equilibrium, 2) showed Na+ -independent coupling of the influx of L(+)lactate and the efflux of L(+) but not to the efflux of D(-)lactate, 3) was not inhibited by D(-)lactate, 2-thiolactate or 3-phenyl-lactate, but 4) was inhibited by 3-thiolactate and alpha-hydroxybutyrate and 5) was accelerated by changes in inwardly directed ionic gradients or by increases in cation conductance both of which led to increased intravesicular positivity. The latter changes had the opposite effect on the uptake of L(+)lactate by BBV. Thus, while the L(+)lactate transport system present in BBV showed the characteristics of Na-dependent electrogenic cotransport system, that in the BLV was consistent with a carrier mediated Na-dependent, facilitated diffusion system.
利用快速过滤技术，研究了通过差速离心和自由流动电泳分离得到的大鼠肾皮质刷状缘（BBV）和基底外侧（BLV）膜囊泡对L（+）乳酸的摄取。与乳酸向BBV的转运相反，向BLV的转运：1）发现仅向平衡方向进行；2）显示L（+）乳酸的流入与L（+）的流出存在Na+非依赖性偶联，但与D（-）乳酸的流出无关；3）不受D（-）乳酸、2-硫代乳酸或3-苯基乳酸的抑制，但是4）受3-硫代乳酸和α-羟基丁酸的抑制，并且5）通过内向离子梯度的变化或阳离子电导率的增加而加速，这两者都会导致囊泡内正电位增加。后一种变化对BBV摄取L（+）乳酸有相反的影响。因此，虽然BBV中存在的L（+）乳酸转运系统表现出Na+依赖性电生成共转运系统的特征，但BLV中的转运系统与载体介导的Na+依赖性易化扩散系统一致。
