Disturbed pyloric motility in Ws/Ws mutant rats due to deficiency of c-kit-expressing interstitial cells of Cajal.
Interstitial cells of Cajal (ICC) are believed to initiate the basic contractile activity of the gastrointestinal tract. Interstitial cells of Cajal express c-kit receptor tyrosine kinase and are deficient in Ws/Ws mutant rats with a small deletion of the c-kit gene. As Ws/Ws rats show remarkable bile reflux to the stomach, the contraction pressure of the pylorus was compared between Ws/Ws and control +/+ rats. The contraction pressure of the pylorus was measured using a microtransducer, which was inserted through a pin-hole in the anterior wall of the stomach under anesthesia. The magnitude of bile reflux was estimated by measuring the content of bile acids in the stomach. The c-kit messenger RNA-expressing cells were detected by in situ hybridization. Frequency and the maximum pressure of the contraction were comparable between Ws/Ws and +/+ rats, but the duration of the contraction was significantly shorter in Ws/Ws rats than in +/+ rats. The number of c-kit messenger RNA-expressing ICC in the pylorus of Ws/Ws rats was 1.7% that of +/+ rats. The bile reflux observed in Ws/Ws rats was attributed to the decrease in the duration of the pyloric contraction, which appeared to result from the deficiency of c-kit messenger RNA-expressing ICC.
Nakama
A
A
Department of Pathology, Osaka University Medical School, Suita, Japan.
Hirota
S
S
Okazaki
T
T
Nagano
K
K
Kawano
S
S
Hori
M
M
Kitamura
Y
Y
D000821:Animal Feed; D000818:Animals; D001647:Bile Acids and Salts / Q000032:analysis; D011312:Pressure; D019009:Proto-Oncogene Proteins c-kit / Q000096:biosynthesis* / Q000235:genetics; D011708:Pylorus / Q000378:metabolism* / Q000502:physiology*; D051381:Rats; D011922:Rats, Mutant Strains; D013270:Stomach / Q000737:chemistry
D001647:Bile Acids and Salts; D019009:Proto-Oncogene Proteins c-kit