Insulin stimulates Na+, Cl-, Ca2+, and Mg2+ transports in TAL of mouse nephron: cross-potentiation with AVP.

Details

Serval ID
serval:BIB_E34B2F6C3907
Type
Article: article from journal or magazin.
Collection
Publications
Title
Insulin stimulates Na+, Cl-, Ca2+, and Mg2+ transports in TAL of mouse nephron: cross-potentiation with AVP.
Journal
American Journal of Physiology
Author(s)
Mandon B., Siga E., Chabardes D., Firsov D., Roinel N., De Rouffignac C.
ISSN
0363-6127
ISSN-L
0002-9513
Publication state
Published
Issued date
1993
Volume
265
Number
3 Pt 2
Pages
F361-F369
Language
english
Abstract
Insulin (Ins) decreases Na+ delivery in the final urine. To determine whether the loop of Henle participates in this reduction, the effects of Ins were tested on cortical (CTAL) and medullary thick ascending limbs (MTAL) of the mouse nephron, microperfused in vitro. In the MTAL, Ins increased the transepithelial potential difference (Vt) and the Na+ and Cl- net reabsorption fluxes (JNa and JCl, respectively) in a dose-dependent manner, the threshold being below 10(-9) M. At 10(-7) M, Ins reversibly increased JNa and JCl, leaving Mg2+ and Ca2+ fluxes (JMg and JCa, respectively) close to zero. In the CTAL, 10(-7) M Ins reversibly increased Vt, JNa, JCl, JMg, and JCa. In CTAL segments perfused under asymmetrical conditions, with a bath-to-lumen-directed NaCl gradient (lumen 50 mM NaCl, bath 150 mM NaCl), addition of 10(-7) M Ins to the bath resulted in a large increase in JMg and JCa. Thus the responses of CTAL and MTAL to Ins are in all ways similar to those already reported for the adenosine 3',5'-cyclic monophosphate (cAMP)-generating hormones acting on these nephron segments. When 10(-10) M arginine vasopressin (AVP) and 10(-7) M Ins were used in combination, previous addition of one hormone to the bath potentiated the response to the second hormone. In cAMP accumulation experiments, performed in the presence of a phosphodiesterase inhibitor, the amounts of cAMP formed with 10(-7) M Ins and 10(-10) M AVP (which elicit maximal physiological responses in these segments) were in the same range.(ABSTRACT TRUNCATED AT 250 WORDS)
Keywords
Animals, Arginine Vasopressin/pharmacology, Biological Transport/drug effects, Calcium/metabolism, Chlorides/metabolism, Drug Synergism, Electrolytes/metabolism, Electrophysiology, Epithelium/physiology, Insulin/pharmacology, Kidney Cortex, Kidney Medulla, Loop of Henle/metabolism, Magnesium/metabolism, Mice, Mice, Inbred Strains, Nephrons/metabolism, Nephrons/physiology, Sodium/metabolism
Pubmed
Web of science
Create date
24/01/2008 12:32
Last modification date
20/08/2019 16:07
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