title: Renal tubular uptake of protein: effect of pH.
abstract: The present study was performed to determine to what extent pH influences protein reabsorption in renal proximal tubule cells. Rat surface proximal tubules were microinfused in vivo with 125I-labelled albumin in buffer solutions at different pHs. Tubular uptake was determined as the difference between microinfused and urinary trichloroacetic acid-precipitable radioactivity. In separate experiments the tubular uptake was followed by electron microscope autoradiography. The results showed that the uptake at pH 4.5 and 6.0 was about 15% higher as compared to uptake at pH 7.4. Furthermore, the electron microscope autoradiography demonstrated that albumin is taken up by endocytosis at acid pH as under normal conditions.
mesh_terms: D000818:Animals; D001345:Autoradiography; D006863:Hydrogen-Ion Concentration; D007687:Kidney Tubules, Proximal / Q000378:metabolism*; D008297:Male; D008854:Microscopy, Electron; D011506:Proteins / Q000378:metabolism*; D011507:Proteinuria / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains; D012711:Serum Albumin, Radio-Iodinated; D014238:Trichloroacetic Acid
chemical_list: D011506:Proteins; D012711:Serum Albumin, Radio-Iodinated; D014238:Trichloroacetic Acid