Nikiforov A A, Bresler V M
Tsitologiia. 1984 Jan;26(1):75-82.
The influence of Cd++ (as well as of Hg++ and Cu++) on the uptake of an organic acid (fluorescein) in superficial proximal tubules of the surviving rat kidney was studied at 20 degrees C, when the active transport of fluorescein does not depend on the external Na. In contrast to mercury and copper, cadmium stimulated the uptake of fluorescein from the beginning of incubation. The minimal effective concentration of Cd++ was 5 X 10(-6)M, the relative effect of Cd++ on the uptake being the same within the concentration range from 5 X 10(-6) to 10(-3) M. A 60 minutes pre-incubation with Cd++ at 20 degrees C resulted in a significant increase in the stimulatory effect of acetate on the fluorescein transport. The stimulation of the fluorescein transport by cadmium was prevented by ouabain or by omissing Na from the incubating medium, although neither ouabain nor the absence of Na affected the transport of fluorescein under these conditions. It is supposed that the stimulation by Cd++ of the fluorescein transport may result from the activated oxidation of NAD-linked substrates due to acceleration of the active transepithelial transport of Na ions.
在20℃下研究了Cd++（以及Hg++和Cu++）对存活大鼠肾脏浅表近端小管中有机酸（荧光素）摄取的影响，此时荧光素的主动转运不依赖于细胞外Na。与汞和铜不同，镉从孵育开始就刺激荧光素的摄取。Cd++的最小有效浓度为5×10(-6)M，在5×10(-6)至10(-3)M的浓度范围内，Cd++对摄取的相对作用相同。在20℃下用Cd++预孵育60分钟导致乙酸盐对荧光素转运的刺激作用显著增加。哇巴因或从孵育介质中去除Na可阻止镉对荧光素转运的刺激，尽管在这些条件下哇巴因和缺乏Na均不影响荧光素的转运。据推测，Cd++对荧光素转运的刺激可能是由于Na离子主动跨上皮转运加速导致NAD连接底物的氧化活化所致。
