Unique contractile and structural protein expression in dog ileal inner circular smooth muscle.
This study was designed to test the hypothesis that there is heterogeneous expression of contractile and structural proteins between the smooth muscle cells (SMCs) in the inner and outer circular muscle (ICM and OCM) layers of the ileum. Immunohistochemical staining and quantitation of fresh frozen sections of the dog ileum was performed using protein specific antibodies. Smooth muscle (SM) SMA myosin heavy chain (MHC), alpha- and gamma-SM actin, and vinculin all show greater expression in the ICM relative to the OCM. SMB MHC and fibronectin show the opposite pattern, with greater expression in the OCM relative to the ICM. Differences in expression of these proteins are consistent with proposed differences in function of these muscle layers. Hypotheses regarding muscle tone and the coordination and regulation of peristalsis via these different muscle layers based on this data can now be made and tested.
Eddinger
Thomas J
TJ
Biological Sciences, Marquette University, Milwaukee, WI 53233, USA. thomas.eddinger@marquette.edu
D000199:Actins / Q000096:biosynthesis; D000818:Animals; D004285:Dogs; D007082:Ileum / Q000378:metabolism*; D007150:Immunohistochemistry; D009119:Muscle Contraction / Q000502:physiology*; D009124:Muscle Proteins / Q000096:biosynthesis*; D009130:Muscle, Smooth / Q000378:metabolism*; D018995:Myosin Heavy Chains / Q000096:biosynthesis; D011817:Rabbits; D016596:Vinculin / Q000096:biosynthesis
D000199:Actins; D009124:Muscle Proteins; D016596:Vinculin; D018995:Myosin Heavy Chains