Impairment of kit-dependent development of interstitial cells
alters contractile responses of the murine intestinal tract.
Sato, Daisuke, Zhong-Fang Lai, Naofumi Tokutomi, Yoshiko Tokutomi,
Hitomi Maeda, Satomi Nishikawa, Shin-Ichi Nishikawa, Michio Ogawa,
and Katsuhide Nishi.
Department of Pharmacology, Institute of Molecular Embryology and
Genetics, Department of Surgery, Kumamoto University, School of
Medicine, 2-2-1 Honjo, Kumamoto (860), Japan
APStracts 3:0105G, 1996.
We examined developmental changes in responses of the isolated segment
of the ileum of BALB/c mice treated with a monoclonal antibody (ACK2)
to the receptor tyrosine kinase (Kit) for 4 days postnatally to
pharmacological agents in vitro. Rhythmic contraction and relaxation
of the isolated ileum started to appear on day 4 post partum, and the
sensitivity to acetylcholine (ACh) decreased gradually after birth.
Treatment with ACK2, induced augmentation of contractile responses
and receptor sensitivity of the longitudinal muscle of the ileum to
ACh, bradykinin and prostaglandin F2[alpha]. ACh induced larger
depolarization in smooth muscle cells of the ileum in the ACK2
-treated mice than in the control. Circular muscle responses to these
substances as measured with changes in intraluminal pressure were not
altered by ACK2-treatment. Results suggest that interstitial cells
play an important role not only in the development of the pacemaking
system of the small intestine but also in the functional development
of the contractile properties of the intestinal smooth muscle.
Received 7 November 1994; accepted in final form 18 April 1996.
APS Manuscript Number G444-4.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 28 May 96