Document Detail


Ca2+, Mg2+ and K+ transport in the cortical and medullary thick ascending limb of the rat nephron: influence of transepithelial voltage.
MedLine Citation:
PMID:  8255743     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
Isolated segments of rat cortical (cTAL) and medullary (mTAL) thick ascending limbs were microperfused and the transepithelial net fluxes (JX) were determined by measuring the composition of the collected fluid with an electron microprobe. When perfused with symmetrical solutions both segments showed similar JNa and JCl and lumen-positive transepithelial voltage (Vte = 7-8 mV). JMg, JCa and JK were not significantly different from zero. When perfused with asymmetrical solutions (lumen 50 mM, bath 150 mM NaCl), the mean Vte were 23 mV and 17 mV in the cTAL and mTAL respectively; this rise was accompanied by significant increases in JMg and JCa in the cTAL, but not in the mTAL, and a marked increase in JK in both segments. It is concluded that, in the rat, divalent cations can be reabsorbed in the cTAL, and K+ can be reabsorbed in the cTAL and mTAL. The transport is voltage-dependent. The mTAL can reabsorb neither Mg2+ nor Ca2+, whatever Vte.
Authors:
B Mandon; E Siga; N Roinel; C de Rouffignac
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Publication Detail:
Type:  Journal Article    
Journal Detail:
Title:  Pflügers Archiv : European journal of physiology     Volume:  424     ISSN:  0031-6768     ISO Abbreviation:  Pflugers Arch.     Publication Date:  1993 Sep 
Date Detail:
Created Date:  1994-01-13     Completed Date:  1994-01-13     Revised Date:  2003-11-14    
Medline Journal Info:
Nlm Unique ID:  0154720     Medline TA:  Pflugers Arch     Country:  GERMANY    
Other Details:
Languages:  eng     Pagination:  558-60     Citation Subset:  IM    
Affiliation:
Département de Biologie Cellulaire et Moléculaire, CEA-Saclay, Gif-Sur-Yvette, France.
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MeSH Terms
Descriptor/Qualifier:
Animals
Biological Transport
Calcium / metabolism*
Electric Stimulation
Epithelium / physiology
Female
Kidney Cortex / metabolism*
Kidney Medulla / metabolism*
Magnesium / metabolism*
Nephrons / metabolism*
Potassium / metabolism*
Rats
Rats, Sprague-Dawley
Chemical
Reg. No./Substance:
7439-95-4/Magnesium; 7440-09-7/Potassium; 7440-70-2/Calcium

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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