학술논문
Novel Mechanism for Regulation of Endothelin Synthesis: Role of Extracellular pH.
Document Type
Article
Source
Subject
*ENDOTHELINS
*HYDROGEN-ion concentration
*MESSENGER RNA
*BRANCHED chain amino acids
*PROTEIN synthesis
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Language
ISSN
1015-8987
Abstract
Background/Aims: Several studies suggest that pH may be an important regulator of renal collecting duct endothelin-1 (ET-1) synthesis; the current study was undertaken to examine this interaction. Methods: Rat inner medullary collecting duct (IMCD) cells were exposed to varying extracellular pH and ET-1 biosynthetic pathways assessed. Results: Exposure of IMCD to varying pH revealed a strong direct correlation between media pH and both mature ET-1 and Big ET-1 release. A direct correlation also existed between cellular Big ET-1 content and pH. Varying media pH did not alter ET-1 mRNA content nor did it affect activity of a transfected 3.2 kb ET-1 promoter. Media pH did not affect ET-1 degradation nor did it alter IMCD cell total protein synthesis (3H-leucine incorporation). Attempts to measure ET-1 mRNA translation rate using His-Tag labeled ET-1 cDNA were not successful. Conclusion: pH regulates IMCD ET-1 production through regulation of either mRNA translation or preproET-1 cleavage. This represents a novel mechanism for regulation of ET-1 synthesis. Copyright © 2008 . Karger AG, Basel [ABSTRACT FROM AUTHOR]