Ma. Wilschanski et al., IN-VIVO MEASUREMENTS OF ION-TRANSPORT IN LONG-LIVING CF MICE, Biochemical and biophysical research communications, 219(3), 1996, pp. 753-759
The Cftr (Cystic Fibrosis Transmembrane Conductance Regulator) gene co
des for an epithelial chloride (C1) channel essential for fluid secret
ion into the respiratory and gastrointestinal tract and from exocrine
glands. Mice lacking CFTR function due to a disruption of Cftr exon 10
or exon I (Cftr(mlUNC/mlUNC) or Cftr(mlHSC/mlHSC) mice, respectively)
generally suffer from severe gastrointestinal disease resulting in de
ath shortly after birth or at the time of weaning. However, a subgroup
of the Cftr(mlHSC/mlHSC) mice have been characterized which exhibit r
elatively mild intestinal pathology resulting in a noncompromised life
span compared to the more severely affected Cftr(mlUNC/mlUNC) mice. We
compared the ion transport capacity of the intestinal mucosa of the m
ildly and severely affected CF mice using the in viva technique of rec
tal potential difference (PD) measurement and found that the net calci
um-activated chloride conductance toward the lumen was much greater in
the rectum of mildly affected mice than in the severely affected mice
. Hence, the milder phenotype may be related to the expression of a fa
ctor which enhances the net calcium-activated chloride conductance int
o the lumen of the intestinal tract. (C) 1996 Academic Press, Inc.