1996 Fiscal Year Final Research Report Summary
Involvement of Enteric Nervous System in the Regulation of Gastrointestinal Motility
| Project/Area Number |
07671384
|
|---|
| Research Category |
Grant-in-Aid for Scientific Research (C)
|
| Allocation Type | Single-year Grants |
|---|
| Section | 一般 |
|---|
| Research Field |
Digestive surgery
|
|---|
| Research Institution | Shiga University of Medical Science |
|---|
Principal Investigator |
FUJIMURA Masaki Shiga University of Medical Science Surgery, Associate Professor, 医学部, 講師 (50115771)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
FUJIMIYA Mineko Shiga University of Medical Science Anatomy, Assistant Professor, 医学部, 助手 (10199359)
|
|---|
| Project Period (FY) |
1995 – 1996
|
| Keywords | peristalsis / ENS / ex vivo isolated vascularly perfused intestinal model / serotonin depleted model / p-chlorophenylalanine (PCPA) / serotonin / serotonin receptor / serotonin receptor antagonist |
|---|
| Research Abstract |
Serotonin (5-HT)-containing neurons in the gastrointestinal (GI) tract are thought to function as interneurons in the enteric nervous system. However, the details of the action of 5-HT on GI function has not been clarified. The purpose of the present study was to clarify the functional role of 5-HT on the motor activity of the intestine by using an ex vivo model of isolated, vasculary perfused rat duodenum. We especially saught to investigate the involvement of 5-HT3 and 5-HT4 receptors on peristaltic movement of the bowel.
Method : The duodenal segment between pylorus and ligament of Treiz was vascularly perfused with O2 saturated Krebs' bicarbonate solution containing 3% dextran and 0.2% BSA.The motor activity was measured by a manometric method as follows : two manometric catheters were inserted through the pylorus and the tips were placed at 3 and 8 cm distant from the pylorus. Motor activity of duodenum in p-chlorophenylalanine (PCPA) treated animala, 5-HT depleted model, was exami
… More
ned in ex vivo isolated vascularly perfused preparation. Different 5HT receptor antagonists such as methysergide (5-HT1), ketanserin (5-HT2), granisetron and azasetron (5-HT3) and SB204070 (5-HT4) were introduced into the perfusate. The effect of these drugs on motor index (MI), %MI (% of control value) and frequency were compared with controls.
Result : In normal conditions the motor activity was observed to consiste of a period of quiescence followed by contractions. Such contractile activity was defined as clusters of phasic contractions (COC). The frequency of CPC was 0.991+0.052/min, the duration was 30.0+2.0sec and the MI was 655+89cm H20/sec. Both mucosal and musclar layr 5-HT content were significantly lower than that in controls. Neither 5-HT1 (1 mM methysergide) nor 5-HT2 (10 mM ketanserin) changed the pattern of CPC.5-HT3 (0.1 nM granisetron) decreased % MI and the frequency of CPC.5-HT4 (0.1 nM SB204070) did not affect the frequency of CPC,however it decreased % MI of CPC.
Conclusion : Endogenous 5-HT may affect the motor activity in the rat duodenum and this action seems to be mediated by 5-HT3 and 5-HT4 receptpors. Less
|
