Expression of a sodium bicarbonate cotransporter in human parotid salivary glands.
Arch Oral Biol
; 47(1): 1-9, 2002 Jan.
Article
en En
| MEDLINE
| ID: mdl-11743927
ABSTRACT
The human parotid gland secretes much of the bicarbonate that enters the mouth. Prompted by studies of animal models, this study sought evidence for the expression of a functional Na(+)-HCO(3)(-) cotransporter (NBC) in human parotid acinar cells. Microfluorometric measurements of intracellular pH in isolated acini showed that the recovery from an acid load was achieved in part by HCO(3)(-) uptake via a Na(+)-dependent, DIDS-sensitive mechanism. By reverse transcriptase-polymerase chain reaction, a full-length NBC1 clone was obtained showing more than 99% homology with the human pancreatic isoform hpNBC1. Expressed in Xenopus oocytes, the electrogenicity of the transporter was detected as an inwardly directed, Na(+)- and HCO(3)(-)-dependent flux of negative charge. Immunohistochemistry using antibodies raised to NBC1 showed strong staining of the basolateral membrane of the acinar cells. Therefore, it was concluded that a functional electrogenic Na(+)-HCO(3)(-) cotransporter is expressed in the human parotid gland, and that it contributes to pH regulation in the acinar cells and could play a significant part in salivary secretion.
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Colección:
01-internacional
Base de datos:
MEDLINE
Asunto principal:
Glándula Parótida
/
Simportadores de Sodio-Bicarbonato
Idioma:
En
Revista:
Arch Oral Biol
Año:
2002
Tipo del documento:
Article
País de afiliación:
Reino Unido