http://dx.doi.org/10.1111/j.1365-2982.2009.01467.x">
 

Document Type

Journal Article

Department/Unit

School of Chinese Medicine

Title

Increased colonic motility in a rat model of irritable bowel syndrome is associated with up-regulation of L-type calcium channels in colonic smooth muscle cells

Language

English

Abstract

Objective This paper aimed to investigate the relationship between up-regulation of L-type calcium channels and altered motility disorder in a rat model of irritable bowel syndrome (IBS). Methods Male Sprague-Dawley rats were subjected to neonatal maternal separation (NMS) from postnatal day 2-14 or normal handling (NH), and used when weighted 250-300 g. Colonic smooth muscle contractions was studied in an organ bath system. L-type Ca2+ channel α1c subunit expression in smooth muscles from rat colon were studied by immunofluorescence and Western blotting analysis. The intracellular calcium concentration ([Ca2+]i) of enzymatically isolated single colonic smooth muscle cell was studied with laser confocal fluorescent microscopy. Results The fecal pellets during 1 h water avoidance stress (WAS) were significantly increased; the amplitude of spontaneous contractions and contractions induced by Bay K 8644 (10 nm-1 μm), KCl (10-60 mm) and ACh (100 nm-10 μm) were significantly increased in NMS rats, when comparing with that of NH rats. [Ca2+]i induced by Bay K 8644 (1 μm), KCl (40 mm), and ACh (10 μm) significantly increased in muscle cells of NMS rats than NH rats. Further, α1c protein expression was significantly up-regulated in colonic smooth muscle of NMS rats than NH rats. Conclusion These results suggest that NMS lead to up-regulation of L-type Ca2+ channels expression in the colon, which contributes to the colonic motility disorder. Our findings provide direct evidence to help understanding the underlying mechanism of chronic stress-induced colonic motility disorder in IBS. © 2010 Blackwell Publishing Ltd.

Keywords

Irritable bowel syndrome, L-type Ca2+ channel, Motility disorder, Neonatal maternal separation

Publication Date

2010

Source Publication Title

Neurogastroenterology and Motility

Volume

22

Issue

5

Start Page

e162

End Page

e170

Publisher

Wiley

ISSN (print)

13501925

ISSN (electronic)

13652982

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