کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
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3885350 | 1249510 | 2007 | 8 صفحه PDF | دانلود رایگان |
Secretion of cationic drugs and endogenous metabolites is a major function of the kidney accomplished by tubular organic cation transport systems. A cationic styryl dye (ASP+) was developed as a fluorescent substrate for renal organic cation transporters. The dye was injected intravenously and continuously monitored in externalized rat kidneys by time-resolved two-photon laser scanning microscopy. To investigate changes in transport activity, cimetidine, a competitive inhibitor of organic cation transport was co-injected with ASP+. Shortly after injection, fluorescence increased in peritubular capillaries. Simultaneously, fluorescence was transiently found at the basolateral membrane of the proximal and distal tubules at a higher intensity and shorter wavelength indicating membrane association of ASP+. Subsequently, intracellular fluorescence increased steeply within 10 s. In the proximal tubules, intracellular fluorescence decreased by 50% within 5 min, while in the distal tubules the fluorescence decreased by only 5% within the same time frame. Intracellular uptake of ASP+ into proximal tubules was significantly reduced by cimetidine. Our studies show that organic cation transport of the kidney can be visualized in vivo by two-photon laser scanning microscopy.
Journal: Kidney International - Volume 72, Issue 4, 2 August 2007, Pages 422–429