Disturbed intestinal movement, bile reflux to the stomach, and deficiency of c-kit-expressing cells in Ws/Ws mutant rats.
OBJECTIVE
Interstitial cells of Cajal (ICCs) are believed to initiate the basic contractile activity of the gastrointestinal tract. Because ICCs in the intestine of mice express c-kit receptor tyrosine kinase and because rats are more commonly used than mice for pathophysiological investigations of the gastrointestinal tract, the number of the c-kit messenger RNA-expressing cells was compared with gastrointestinal movement in rats.


METHODS
The c-kit messenger RNA-expressing cells were detected by in situ hybridization. The autonomous contraction of excised segments of the ileum was recorded. The function of the pyloric sphincter was evaluated by measuring the content of bile acids in the stomach.


RESULTS
The c-kit messenger RNA-expressing cells were not detectable in the stomach of Ws/Ws mutant rats with a small deletion at the tyrosine kinase domain of c-kit, and the number of c-kit messenger RNA-expressing cells decreased to 7% that of normal control rats in the ileum of Ws/Ws rats. The contractile activity of the ileum was apparently impaired, and the content of bile acids in the stomach was significantly increased in Ws/Ws rats.


CONCLUSIONS
The abnormalities in the ileal movement and pyloric sphincter function in Ws/Ws rats were attributable to the deficiency of c-kit messenger RNA-expressing cells.
Isozaki
K
K
Department of Pathology, Osaka University Medical School, Suita, Japan.
Hirota
S
S
Nakama
A
A
Miyagawa
J
J
Shinomura
Y
Y
Xu
Z
Z
Nomura
S
S
Kitamura
Y
Y
D000818:Animals; D001483:Base Sequence; D001655:Bile Reflux / Q000503:physiopathology*; D003106:Colon / Q000378:metabolism / Q000503:physiopathology; D005753:Gastric Mucosa / Q000378:metabolism; D005769:Gastrointestinal Motility / Q000502:physiology*; D007082:Ileum / Q000378:metabolism / Q000503:physiopathology; D066298:In Vitro Techniques; D008969:Molecular Sequence Data; D011518:Proto-Oncogene Proteins / Q000172:deficiency* / Q000235:genetics; D019009:Proto-Oncogene Proteins c-kit; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D011922:Rats, Mutant Strains; D020794:Receptor Protein-Tyrosine Kinases / Q000172:deficiency* / Q000235:genetics; D016184:Receptors, Colony-Stimulating Factor / Q000172:deficiency* / Q000235:genetics; D013270:Stomach / Q000503:physiopathology
D011518:Proto-Oncogene Proteins; D012333:RNA, Messenger; D016184:Receptors, Colony-Stimulating Factor; D019009:Proto-Oncogene Proteins c-kit; D020794:Receptor Protein-Tyrosine Kinases