Maintenance of morphology and function of canine proximal colon
smooth muscle in organ culture.
Horner, Michelle J., Sean M. Ward, William T. Gerthoffer, Kenton M.
Sanders, and Burton Horowitz.
Department of Physiology and Department of Pharmacology, University
of Nevada, School of Medicine, Reno, Nevada 89557, (702) 784-1462,
Fax: (702) 784-6903
APStracts 3:0214G, 1996.
We have determined that serum source plays a critical role in
optimizing conditions for an organ culture model of canine proximal
colon. Previous studies using equine serum in the media have shown
that some properties of canine colonic smooth muscle can be
maintained in organ culture. However, many characteristics of the
tissue were altered by the culture conditions. The aims of the
present study were to determine whether serum isolated from canine
blood, would improve the preservation of physiological properties of
canine proximal colon in organ culture. Strips of canine colonic
smooth muscle were cultured in 10% canine serum medium and
electrical, mechanical, morphological, and molecular analysis were
performed after 0, 3, and 6 days in culture. Unlike organ culture in
equine serum, in which Na,K-ATPase expression declined, culture in
canine serum maintained Na,K-ATPase expression, and resting membrane
potential of smooth muscle cells along the submucosal surface of the
circular muscle in cultured tissue remained unchanged during the
culture period. Increased sensitivity in the contractile response to
acetylcholine, previously observed with tissues cultured in equine
serum, was not observed. However, the mechanical performance of the
muscle (maximal contractile activity) declined over time in culture.
Ultrastructural organization of cellular organelles and myofilaments
remained intact in the majority of cells, however, some cells
possessed regions devoid of contractile filaments. The results of
these studies suggest that organ cultured strips of smooth muscle may
provide a useful tool for evaluating electrical and mechanical events
in conjunction with molecular analysis of functional components.
Received 18 December 1995; accepted in final form 4 October 1996.
APS Manuscript Number G525-5.
Article publication pending Am. J. Physiol. (Gastrointest. Liver
Physiology).
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 5 November 1996