Document Detail

H(2) O(2) stimulates Cl(-) /HCO 3- exchanger activity through oxidation of thiol groups in immortalized SHR renal proximal tubular epithelial cells.
MedLine Citation:
PMID:  21815192     Owner:  NLM     Status:  Publisher    
Cl(-) /HCO 3- exchanger and Na(+) /H(+) exchanger 3 are the main transporters responsible for NaCl reabsorption in kidney proximal tubules. It is well accepted that membrane exchangers can be regulated by reactive oxygen species (ROS). In the kidney, ROS are known to contribute to decreases in Na(+) excretion and consequently increase blood pressure. The present study investigated mechanisms by which H(2) O(2) -induced stimulation of Cl(-) /HCO 3- exchanger activity is enhanced in proximal tubular epithelial (PTE) cells immortalized from spontaneously hypertensive rats (SHR) as compared to normotensive Wistar Kyoto (WKY). H(2) O(2) decreased K(m) values for Cl(-) /HCO 3- exchanger activity in SHR PTE cells, but had no effect on the kinetic parameters in WKY cells. DTDP stimulated in a concentration-dependent manner Cl(-) /HCO 3- exchanger activity in both cell lines, but SHR PTE cells were 2.4-fold more responsive to this oxidant. In contrast, thimerosal had no effect on exchanger activity in both cell lines. The effects of H(2) O(2) and DTDP upon the exchanger activity were blocked by DTT in WKY and SHR PTE cells. Similar to H(2) O(2) , DTDP decreased K(m) values for Cl(-) /HCO 3- exchanger activity in SHR PTE cells. Basal content of free thiol groups was higher in WKY PTE cells than in SHR. Upon H(2) O(2) treatment the free thiol groups decreased in both cell lines; however, this decrease was more pronounced in WKY cells. In conclusion, in SHR PTE cells H(2) O(2) stimulates Cl(-) /HCO 3- exchanger activity via modification of thiol groups of intracellular and/or transmembrane protein. Furthermore, the thiol oxidation-dependent pathway also increases the HCO 3- affinity in SHR PTE cells. J. Cell. Biochem. © 2011 Wiley-Liss, Inc.
Sónia Simão; Pedro Gomes; Maria João Pinho; Patrício Soares-da-Silva
Publication Detail:
Type:  JOURNAL ARTICLE     Date:  2011-8-3
Journal Detail:
Title:  Journal of cellular biochemistry     Volume:  -     ISSN:  1097-4644     ISO Abbreviation:  -     Publication Date:  2011 Aug 
Date Detail:
Created Date:  2011-8-4     Completed Date:  -     Revised Date:  -    
Medline Journal Info:
Nlm Unique ID:  8205768     Medline TA:  J Cell Biochem     Country:  -    
Other Details:
Languages:  ENG     Pagination:  -     Citation Subset:  -    
Copyright Information:
Copyright © 2011 Wiley-Liss, Inc.
Department of Pharmacology and Therapeutics, Faculty of Medicine, University of Porto, 4200-319 Porto, Portugal.
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