|
KMID : 0376420010250020129
|
|
Chonbuk University Medical Journal
2001 Volume.25 No. 2 p.129 ~ p.135
|
|
|
EFFECTS OF BILE ACIDS ON MEMBRANE EXCITABILITY IN COLONIC CIRCULAR MYOCYTES
|
|
Hye Kyung Lee
Mi Young Lim/Kyoung Hwa Lee
|
|
|
Abstract
|
|
|
Objectives: Under normal conditions bile acids are actively reabsorbed at the distal ileum and recirculated efficiently by enterohepatic circulation. However, in some pathological conditions, such as ileal mucosa inflammation of following ileocecal resection, bile acid reabsorption is compromised and these compounds pass into the colon, which could result in the alteration of the intestinal motility. The present study therefore was to examine whether bile acids can modulate electrical slow waves of colonic smooth muscle, which are closely coupled with muscle contractility.
Methods: The effects of bile acids were determined by measuring membrane potential of intact strips of canine colonic circular muscle using a conventional intracellular recording technique. Fresh bile diluted with Krebs solution and some known components of bile acids were applied in Krebs solution continuousluy perfusing the recording chamber.
Results: Fresh bile depolarized the membrane potential in a concentration-dependent manner with alteration of slow wave duration. At 5%, bile increased the frequency of slow waves. Component of bile deoxycholic acid and tauricholic acid depolarized the cell membrane but with inconsistent changes in slow wave duration. Cholic acid, however, at 300цM membrane potential was not visibly altered.
Conclusion: The results from this study suggest that bile acids exert both excitatory and inhibitory actions in canine colonic muscle. Bile acids appear to modulate smooth muscle function directly as well as indirectly via their effects on nerve and/or Cajal cell. Further study to ascertain pathophysiological role(s) of bile acids is needed.
|
|
|
KEYWORD
|
|
|
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|
|