Ion transport across the murine intestine in the absence and presence of CFTR.
CF mice, i.e., mice without functional CFTR (cystic fibrosis transmembrane conductance regulator) exhibit a very low basal Isc in all regions of the intestinal tract. The low basal Isc in the intestinal epithelia of the CF mice appears to be a result of lack of spontaneous Cl- secretion (and possibly HCO3- secretion) mediated by neurotransmitter release from the enteric nervous system. In contrast to intestinal epithelia from normal mice, the intestinal epithelia of CF mice do not secrete Cl- in response to agents that increase cAMP (forskolin). Furthermore, as in human CF patients, agents that increase intracellular Ca2+ (bethanacol, ionomycin) failed to elicit Cl- secretion in the intestinal epithelia of CF mice. There was no difference in the electrogenic Na(+)-coupled glucose absorption in the CF murine jejuna compared to jejuna from normal mice. However, further studies are warranted to determine whether amiloride-sensitive Na+ absorption is upregulated in the murine CF colon. It was concluded that the intestinal epithelium of the CF mouse model exhibits some striking similarities to its human counterpart, and therefore should be very useful in further characterizing the ion transport defects in this disease.
Grubb
B R
BR
Cystic Fibrosis/Pulmonary Research and Treatment Center, University of North Carolina at Chapel Hill 27599-7020, USA.
D000818:Animals; D018723:Bethanechol / Q000494:pharmacology; D002712:Chlorides / Q000502:physiology; D005576:Colforsin / Q000494:pharmacology; D019005:Cystic Fibrosis Transmembrane Conductance Regulator / Q000502:physiology*; D006801:Humans; D007408:Intestinal Absorption / Q000502:physiology; D007413:Intestinal Mucosa / Q000378:metabolism*; D017136:Ion Transport; D015759:Ionomycin / Q000494:pharmacology; D051379:Mice; D012016:Reference Values; D012964:Sodium / Q000493:pharmacokinetics; D013779:Tetrodotoxin / Q000494:pharmacology
C505032:CFTR protein, human; D002712:Chlorides; D018723:Bethanechol; D019005:Cystic Fibrosis Transmembrane Conductance Regulator; D005576:Colforsin; D013779:Tetrodotoxin; D015759:Ionomycin; D012964:Sodium