The effect of varying tonicity on nasal epithelial ion transport in cystic fibrosis.
Am J Respir Crit Care Med
; 171(7): 760-3, 2005 Apr 01.
Article
em En
| MEDLINE
| ID: mdl-15618459
ABSTRACT
There is reasonable evidence that the fluid layer of the airway epithelium is exposed to changes in tonicity. The inspiration of cool, dry air causes an increased tonicity, whereas this tonicity may be decreased by glandular secretions. We hypothesized that the cystic fibrosis transmembrane conductance regulator (CFTR) is involved in the responses to changes in tonicity and that these may be altered in cystic fibrosis (CF). Using nasal potential difference (PD) protocols in 8 subjects with CF and 10 subjects without CF, we investigated the effects of hyper- and hypotonicity on ion transport processes. We found significant differences between the two groups. In response to a hypertonic challenge (mannitol 500 mM), there was a decreased PD in both groups, suggesting decreased sodium absorption. However, after the prior inhibition of sodium transport using amiloride, there was an increased PD in the non-CF group alone, suggesting CFTR-mediated chloride secretion in response to luminal hypertonicity. For the hypotonic solution, we found that hypotonicity inhibited CFTR-mediated chloride secretion in the non-CF group. These data suggest that CFTR plays a role in the recognition and regulation of airway fluid tonicity.
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Coleções:
01-internacional
Base de dados:
MEDLINE
Assunto principal:
Transporte de Íons
/
Regulador de Condutância Transmembrana em Fibrose Cística
/
Fibrose Cística
/
Mucosa Nasal
Tipo de estudo:
Diagnostic_studies
/
Observational_studies
Limite:
Adult
/
Female
/
Humans
/
Male
Idioma:
En
Ano de publicação:
2005
Tipo de documento:
Article