HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) All Versions of this Article: 297/5/G1028    most recent 90692.2008v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Tanaka, R. Articles by Fujimiya, M. PubMed PubMed Citation Articles by Tanaka, R. Articles by Fujimiya, M.

INNOVATIVE METHODOLOGY

New method of manometric measurement of gastroduodenal motility in conscious mice: effects of ghrelin and Y2 depletion

¹Department of Social and Behavioral Medicine, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima; ²Research Institute, Taiko Pharmaceutical Co., Ltd., Osaka; and ³Department of Anatomy, Sapporo Medical University, School of Medicine, Sapporo, Japan

Submitted December 10, 2008 ; accepted in final form September 2, 2009

Since no previous studies have reported dual measurements of stomach and duodenal motility in conscious mice, we developed a manometric method to measure the gastroduodenal motility in the physiological fed and fasted states of conscious mice. By this method we measured, for the first time, the gastroduodenal motility in Y2 knockout mice and analyzed the effects of ghrelin on the gastroduodenal motility in conscious mice. To evaluate this new method, we provide the comparison on the effects of CCK-8 examined by present and previous methods. In the fasted state of mice, phase III-like contractions with frequencies of 7.8 ± 0.5 contractions/h in the antrum and 6.6 ± 0.7 contractions/h in the duodenum were observed. This fasted pattern was disrupted and replaced by the fed pattern after feeding, with an increase of the motor index (MI) immediately after feeding. Intravenous injection of ghrelin induced the fasted pattern in the duodenum when injected in the fed state and increased %MI (114.3 ± 9.8%) compared with saline-injected controls (64.4 ± 9.6%) in the antrum. Intravenous injection of CCK-8 disrupted phase III-like contractions in both antrum and duodenum, which were replaced by fed-like motor patterns accompanied with the elevation of baseline pressure. In Y2 knockout mice, the frequency of phase III-like contractions was decreased in the antrum compared with wild-type mice and the immediate increase of MI after feeding seen in wild-type mice was disrupted in Y2 knockout mice. Our model provides a new method for studies of gastrointestinal motility in various mouse models, including transgenic and knockout ones.

Y2 knockout; fed and fasted motility