Neuronal adrenergic and muscular cholinergic contractile hypersensitivity in canine jejunum after extrinsic denervation.
Extrinsic denervation may be responsible for motor dysfunction after small bowel transplantation. The aim of this study was to examine the role of extrinsic innervation of canine jejunum on contractile activity. An in vitro dose response of cholinergic and adrenergic agonists was evaluated in canine jejunal strips of circular muscle at 0, 2, and 8 weeks in a control group and after jejunoileal extrinsic denervation (EX DEN). Neurons in circular muscle were quantitated by means of immunohistochemical techniques. Adrenergic and cholinergic responses did not differ at any time in the control group. However, at 2 and 8 weeks, extrinsic denervation caused an increased sensitivity to the procontractile effects of the cholinergic agonist bethanechol at the level of the smooth muscle cells, and increased sensitivity to the inhibitory effects of the adrenergic agent norepinephrine mediated at the level of the enteric nervous system. Immunohistochemical analysis showed a reduction in all neurons and a complete lack of adrenergic fibers in the EX DEN group after 2 and 8 weeks. Extrinsic denervation induces enteric neuronal cholinergic and adrenergic smooth muscle hypersensitivity in canine jejunal circular muscle.
Balsiger
Bruno M
BM
Department of Visceral and Transplantation Surgery, University of Bern, Bern, Switzerland.
He
Chong-Liang
CL
Department of Surgery and the Gastroenterology Research Unit, Mayo Clinic, Rochester, Minnesota.
Zyromski
Nicholas J
NJ
Department of Surgery, Medical College of Ohio, Toledo, Ohio.
Sarr
Michael G
MG
Department of Surgery and the Gastroenterology Research Unit, Mayo Clinic, Rochester, Minnesota.
D000109:Acetylcholine / Q000494:pharmacology; D000320:Adrenergic Fibers / Q000502:physiology*; D000316:Adrenergic alpha-Agonists / Q000494:pharmacology; D000818:Animals; D018723:Bethanechol / Q000494:pharmacology; D002799:Cholinergic Fibers / Q000502:physiology*; D003714:Denervation; D004285:Dogs; D004305:Dose-Response Relationship, Drug; D005769:Gastrointestinal Motility / Q000502:physiology*; D007150:Immunohistochemistry; D066298:In Vitro Techniques; D007583:Jejunum / Q000294:innervation*; D023421:Models, Animal; D018721:Muscarinic Agonists / Q000494:pharmacology; D009119:Muscle Contraction / Q000502:physiology*; D009130:Muscle, Smooth / Q000294:innervation*; D009474:Neurons / Q000378:metabolism / Q000502:physiology*; D009638:Norepinephrine / Q000494:pharmacology
D000316:Adrenergic alpha-Agonists; D018721:Muscarinic Agonists; D018723:Bethanechol; D000109:Acetylcholine; D009638:Norepinephrine