Pflügers Archiv

, Volume 412, Issue 5, pp 516–523

Differential effects of ADH on sodium, chloride, potassium, calcium and magnesium transport in cortical and medullary thick ascending limbs of mouse nephron

Authors

  • M. Wittner
    • Service de Biologie Cellulaire, Département de Biologie/CEACEN Saclay
    • Institut für PhysiologieAlbert-Ludwigs-Universität
  • A. di Stefano
    • Service de Biologie Cellulaire, Département de Biologie/CEACEN Saclay
    • Institut für PhysiologieAlbert-Ludwigs-Universität
  • P. Wangemann
    • Institut für PhysiologieAlbert-Ludwigs-Universität
  • R. Nitschke
    • Institut für PhysiologieAlbert-Ludwigs-Universität
  • R. Greger
    • Institut für PhysiologieAlbert-Ludwigs-Universität
  • C. Bailly
    • Unité INSERM 251Faculté de Médecine Xavier Bichat
  • C. Amiel
    • Unité INSERM 251Faculté de Médecine Xavier Bichat
  • N. Roinel
    • Service de Biologie Cellulaire, Département de Biologie/CEACEN Saclay
  • C. de Rouffignac
    • Service de Biologie Cellulaire, Département de Biologie/CEACEN Saclay
Transport Processes, Metabolism and Endocrinology; Kidney, Gastrointestinal Tract, and Exocrine Glands

DOI: 10.1007/BF00582541

Cite this article as:
Wittner, M., di Stefano, A., Wangemann, P. et al. Pflugers Arch. (1988) 412: 516. doi:10.1007/BF00582541

Abstract

The effect of antidiuretic hormone (arginine vasopressin, AVP) on transepithelial Na+, Cl, K+, Ca2+ and Mg2+ net transports was investigated in medullary (mTAL) and cortical (cTAL) segments of the thick ascending limb (TAL) of mouse nephron, perfused in vitro. Transepithelial net fluxes (JNa+,JCl,JK+,JCa2+,JMg2+) were determined by electron probe analysis of the collected tubular fluid. Transepithelial potential difference (PDte) and transepithelial resistance (Rte) were measured simultaneously. cTAL segments were bathed and perfused with isoosmolal, HCO3 containing Ringer solutions, mTAL segments were bathed and perfused with isoosmolal HCO3 free Ringer solutions. In cTAL segments, AVP (10−10 mol·l−1) significantly increasedJMg2+ andJCa2+ from 0.39±0.08 to 0.58±0.10 and from 0.86±0.13 to 1.19±0.15 pmol·min−1 mm−1 respectively. NeitherJNa+ norJCl, (JNa+: 213±30 versus 221±28 pmol·min−1 mm−1,JCl: 206±30 versus 220±23 pmol·min−1 mm−1) nor PDte (13.4±1.3 mV versus 14.1±1.9 mV) or Rte (24.6±6.5Ω cm2 versus 22.6±6.4Ω cm2) were significantly changed by AVP. No significant effect of AVP on net K+ transport was observed. In mTAL segments, Mg2+ and Ca2+ net transports were close to zero and AVP (10−10 mol·l−1) elicited no effect. However NaCl net reabsorption was significantly stimulated by the hormone,JNa+ increased from 107±33 to 148±30 andJCl from 121±33 to 165±32 pmol·min−1 mm−1. The rise inJNaCl was accompanied by an increase in PDte from 9.0±0.7 to 13.5±0.9 mV and a decrease in Rte from 14.4±2.0 to 11.2±1.7 Ω cm2. No K+ net transport was detected, either under control conditions or in the presence of AVP.

To test for a possible effect of HCO3 on transepithelial ion fluxes, mTAL segments were bathed and perfused with HCO3 containing Ringer solutions. With the exception ofJCa2+ which was significantly different from zero (JCa2+: 0.26±0.06 pmol·min−1 mm−1), net transepithelial fluxes of Na+, Cl, K+ and Mg2+ were unaffected by HCO3. In the presence of AVP,JMg2+ andJCa2+ were unaltered whereasJNaCl was stimulated to the same extent as observed in the absence of HCO3. In conclusion our results indicate heterogeneity of response to AVP in cortical and medullary segments of the TAL segment, since AVP stimulates Ca2+ and Mg2+ reabsorption in the cortical part and Na+ and Cl reabsorption in the medullary part of this nephron segment.

Key words

ADHTransepithelial ion net fluxesNa+, Cl, K+, Ca2+ and Mg2+ transportElectron microprobeMouse kidneyCortical and medullary thick ascending limb of Henle's loopIn vitro microperfusion

Copyright information

© Springer-Verlag 1988