English
 
Help Privacy Policy Disclaimer
  Advanced SearchBrowse

Item

ITEM ACTIONSEXPORT
  Cell pH of rat renal proximal tubule in vivo and the conductive nature of peritubular HCO3-(OH-) exit

Yoshitomi, K., & Frömter, E. (1984). Cell pH of rat renal proximal tubule in vivo and the conductive nature of peritubular HCO3-(OH-) exit. Pflügers Archiv: European Journal of Physiology, 402(3), 300-305. doi:10.1007/BF00585513.

Item is

Basic

show hide
Genre: Journal Article

Files

show Files

Locators

show

Creators

show
hide
 Creators:
Yoshitomi, K.1, 2, Author              
Frömter, Eberhard1, 2, Author              
Affiliations:
1Department of Physiology, Max Planck Institute of Biophysics, Max Planck Society, ou_2068297              
2Zentrum der Physiologie, Johann-Wolfgang-Goethe-Universität, Theodor-Stern-Kai 7, D-6000, Frankfurt/Main 70, Federal Republic of Germany, ou_persistent22              

Content

show
hide
Free keywords: Rat proximal tubule cell pH; Peritubular membrane HCO3 transport; Cellular buffering power; Double-barrelled pH microelectrodes
 Abstract: Intracellular pH (pHc) was measured on surface loops of rat kidney proximal tubules under free-flow conditions in vivo using fine tip double-barrelled pH microelectrodes based on a neutral H+ ligand. The microelectrodes had Nernstian slopes and a resistance of the order of 1012 Ω. By using a driven shield feed back circuit the response time to pH jumps was lowered to around 1 s. At a peritubular pH of 7.42 and a luminal pH of 6.68 ± 0.13 (n=27), pHc was 7.17 ± 0.08 (n=19). Perfusing the peritubular capillaries suddenly with bicarbonate Ringer solutions of plasma-like composition which were equilibrated with high or low CO2 pressures, acidified or respectively alkalinized the cells rapidly as expected from the high CO2 permeability of the cell membranes. Such data allowed us to calculate the cytoplasmic buffering power of the tubular cells. Sudden peritubular perfusion with Ringer solution containing only 3 mmol/l of HCO3 at constant physiological CO2 pressure led to a similar fast cell acidification which indicated that the peritubular cell membrane is also highly permeable for bicarbonate or OH (H+). The latter response was completely blocked by the stilbene derivative SITS at the concentration of 10−3 mol/l. The observations indicate first that pHc of rat proximal tubule is more acidic than was previously thought on the basis of distribution studies of weak acids, second that intracellular bicarbonate concentration is around 13 mmol/l and third that bicarbonate exit across the peritubular cell membrane is a passive rheogenic process via a conductive pathway which can be inhibited by SITS. The latter point confirms the conclusion which we had derived previously from membrane potential measurements in response to changing peritubular bicarbonate concentrations.

Details

show
hide
Language(s): eng - English
 Dates: 1984-05-081984-07-041984-11-01
 Publication Status: Published in print
 Pages: 6
 Publishing info: -
 Table of Contents: -
 Rev. Type: Peer
 Identifiers: DOI: 10.1007/BF00585513
PMID: 6441147
 Degree: -

Event

show

Legal Case

show

Project information

show

Source 1

show
hide
Title: Pflügers Archiv: European Journal of Physiology
  Other : Pflügers Arch. Europ. J. Physiol.
Source Genre: Journal
 Creator(s):
Affiliations:
Publ. Info: Heidelberg : Springer-Verlag
Pages: - Volume / Issue: 402 (3) Sequence Number: - Start / End Page: 300 - 305 Identifier: ISSN: 0031-6768
CoNE: https://pure.mpg.de/cone/journals/resource/954925432380