Effect of Ureteral Stop Flow on PAH in Lumen and Cortex Homogenate in the Rat Kidney 1

Summary

Stop-flow accumulation of ³H-PAH took place in cells and in lumina of proximal tubules. This strongly suggests that an active PAH is secreted by a “push” system, that is, the pump is located in the peritubular membrane of the cell. The rate of stop-flow accumulation of ³H-PAH in the distal tubules was over three times higher than in proximal tubules, while the concentration of ¹⁴C-inulin was decreasing in the distal tubules. Apparently there is a very active secretory pump for PAH between the proximal and distal convolutions, probably in the straight portion of the proximal tubule.