Reduced myoelectric activity in the sphincter of Oddi in a new model of chronic cholangitis in rabbits: an in vivo and in vitro study.
BACKGROUND
Chronic cholangitis caused by hepatolithiasis is a common disease in Southeast Asia. Few studies have addressed the effects of chronic cholangitis on cyclic activity of the sphincter of Oddi (SO). In this study, we investigated the changes of myoelectric activity in rabbits with chronic cholangitis in vivo and in vitro.


METHODS
Chronic cholangitis was induced in rabbits by initially introducing three pieces of 2-0 silk suture and sequentially injecting E. coli into the choledochus through the tube in ductus cysticus. In in vivo experiments, myoelectric activity of SO was recorded by a circular electrode through the jejunum stump in conscious animals. In in vitro experiments, the SO was completely isolated and the myoelectric activity was recorded by a circular electrode in a 10-mL organ bath filled with Krebs solution, with or without addition of cholecystokinin-8 (CCK-8), KCl, ionomycin or induction of capacitative calcium entry (CCE).


RESULTS
In comparison with control and non-infected rabbits, the rabbits with chronic cholangitis showed higher levels of alkaline phosphatase and gamma-glutamyltransferase and significant pathological changes including increased inflammatory infiltration and collagen deposition in mucosae or muscular layer. Cyclic myoelectric activity of SO at phases 2 and 3 of migrating motor complex and the excitatory response to CCK-8 were dramatically decreased in animals with chronic cholangitis. Myoelectric activity of SO was also significantly decreased in vitro with or without agonists or with induction of CCE.


CONCLUSIONS
Myoelectric activity of SO and its response to agonists are decreased in rabbits with chronic cholangitis both in vivo and in vitro.
Liu
Y-K
YK
Hepatobiliary Surgery Institute, Southwest Hospital, Third Military Medical University, Chongqing, China.
Li
Z-H
ZH
Liu
N-Z
NZ
He
Q
Q
Lin
H
H
Wang
X-J
XJ
Li
X-W
XW
Dong
J-H
JH
D000818:Animals; D002118:Calcium / Q000378:metabolism; D002761:Cholangitis / Q000473:pathology / Q000503:physiopathology*; D002763:Cholecystectomy; D002766:Cholecystokinin / Q000494:pharmacology; D002908:Chronic Disease; D004576:Electromyography / Q000379:methods*; D009119:Muscle Contraction / Q000187:drug effects / Q000502:physiology; D009130:Muscle, Smooth / Q000187:drug effects / Q000502:physiology; D010446:Peptide Fragments / Q000494:pharmacology; D011817:Rabbits; D011897:Random Allocation; D009803:Sphincter of Oddi / Q000187:drug effects / Q000473:pathology / Q000502:physiology* / Q000503:physiopathology*
D010446:Peptide Fragments; C410885:cholecystokinin 8; D002766:Cholecystokinin; D002118:Calcium