Regulatory volume decrease in human esophageal epithelial cells.
Am J Physiol Gastrointest Liver Physiol
; 283(4): G932-7, 2002 Oct.
Article
en En
| MEDLINE
| ID: mdl-12223353
ABSTRACT
In vivo human esophageal epithelial cells are regularly exposed to hyposmolal stress. This stress, however, only becomes destructive when the surface epithelial cell (barrier) layers are breached and there is contact of the hyposmolal solution with the basolateral cell membranes. The present investigation was designed to examine the effects of hyposmolal stress in the latter circumstance using as a model for human esophageal epithelial cells the noncancer-derived HET-1A cell line. Cell volume and the response to hyposmolal stress in suspensions of HET-1A cells were determined by cell passage through a Coulter Counter Multisizer II. HET-1A cells behaved as osmometers over the range of 280 to 118 mosmol/kg H(2)O with rapid increases in cell volume < or = 15-20% above baseline. Following swelling, the cells exhibited regulatory volume decrease (RVD), restoring baseline volume within 30 min, despite continued hyposmolal stress. With the use of pharmacologic agents and ion substitutions, RVD appeared to result from rapid activation of parallel K(+) and Cl(-) conductance pathways and this was subsequently joined by activation of a KCl cotransporter. Exposure to hyposmolal stress in an acidic environment, pH 6.6, inhibited, but did not abolish, RVD. These data indicate that human esophageal epithelial cells can protect against hyposmolal stress by RVD and that the redundancy in mechanisms may, to some extent, serve as added protection in patients with reflux disease when hyposmolal stress may occur in an acidic environment.
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Bases de datos:
MEDLINE
Asunto principal:
Ácido 4,4'-Diisotiocianostilbeno-2,2'-Disulfónico
/
Esófago
Límite:
Humans
Idioma:
En
Revista:
Am J Physiol Gastrointest Liver Physiol
Asunto de la revista:
FISIOLOGIA
/
GASTROENTEROLOGIA
Año:
2002
Tipo del documento:
Article
País de afiliación:
Estados Unidos