ISSN:
1432-2013
Keywords:
BCECF Cell pH Corneal endothelial cells Na+-HCO3– cotransporter RT-PCR
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Abstract. Although bicarbonate transport in corneal endothelium has been suggested to be coupled to Na+, the underlying molecular mechanism has not been clarified. In the present study we investigated whether a recently cloned Na+-HCO3 – cotransporter (NBC-1) is responsible for this process, and, if so, whether the endothelium expresses a separate isoform or one of the other two isoforms that have recently been identified (kNBC-1 from kidney and pNBC-1 from pancreas). Using primers designed for specific and common regions we demonstrated by reverse transcriptase polymerase chain reaction (RT-PCR) that both kNBC-1 and pNBC-1 are expressed in cultured human corneal endothelial cells. In addition functional studies with a pH-sensitive fluorescence probe were performed. In the presence of HCO3 –/CO2 a pH regulatory process was demonstrated which depends on the presence of Na+ and membrane potential, but is independent of Cl– and is inhibited by the disulfonic stilbene DIDS. These results support the presence of NBC-1 as the major bicarbonate transport system in corneal endothelium.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/s004249900081
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