Characterization of the Na+/HCO3¯ cotransport in human neutrophils
Background: Bicarbonate transport has crucial roles in regulating intracellular pH (pH<SUB>i</SUB>) in a variety of cells. The purpose of this study was to evaluate its participation in the regulation of pHi in resting and stimulated human neutrophils. Methods: Freshly isolated human neu...
Guardado en:
| Autores principales: | , , , , , |
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| Formato: | Articulo |
| Lenguaje: | Inglés |
| Publicado: |
2014
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| Materias: | |
| Acceso en línea: | http://sedici.unlp.edu.ar/handle/10915/85267 |
| Aporte de: |
| Sumario: | Background: Bicarbonate transport has crucial roles in regulating intracellular pH (pH<SUB>i</SUB>) in a variety of cells. The purpose of this study was to evaluate its participation in the regulation of pHi in resting and stimulated human neutrophils. Methods: Freshly isolated human neutrophils acidified by an ammonium prepulse were used in this study. Results: We demonstrated that resting neutrophils have a bicarbonate transport mechanism that prevents acidification when the Na<SUP>+</SUP>/H<SUP>+</SUP> exchanger is blocked by EIPA. Neutrophils acidified by an ammonium prepulse showed an EIPA-resistant recovery of pHi that was inhibited by the blocker of the anionic transporters SITS or the Na<SUP>+</SUP>/HCO<SUB>3</SUB>¯ cotransporter (NBC) selective inhibitor S0859, and abolished when sodium was removed from the extracellular medium. In western blot and RT-PCR analysis the expression of NBCe2 but not NBCe1 or NBCn1 was detected in neutrophils Acidified neutrophils increased the EIPA-insensitive pHi recovery rate when its activity was stimulated with fMLF/cytochalasin B. This increase in the removal of acid equivalents was insensitive to the blockade of the NADPH oxidase with DPI. Conclusion: It is concluded that neutrophils have an NBC that regulates basal pH<SUB>i</SUB> and is modulated by chemotactic agents. |
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