| Project/Area Number |
04454124
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| Research Category |
Grant-in-Aid for General Scientific Research (B)
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| Allocation Type | Single-year Grants |
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| Research Field |
General anatomy (including Histology/Embryology)
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| Research Institution | Niigata University |
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Principal Investigator |
FUJITA Tsuneo Niigata University School of Medicine/ Professor, 医学部, 教授 (00032863)
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| Co-Investigator(Kenkyū-buntansha) |
KUWAHARA Atsukazu National Institute for Physiological Sciences, Okazaki National Research Institu, 生理学研究所, 助手 (60142890)
KANAZAWA Hiroaki Niigata University School of Medicine/ Assistant, 医学部, 助手 (40214431)
IWANAGE Toshihiko Niigata University School of Medicine/ Associate Professor, 医学部, 助教授 (10160128)
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| Project Period (FY) |
1992 – 1993
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| Project Status |
Completed (Fiscal Year 1993)
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| Budget Amount *help |
¥7,200,000 (Direct Cost: ¥7,200,000)
Fiscal Year 1993: ¥900,000 (Direct Cost: ¥900,000)
Fiscal Year 1992: ¥6,300,000 (Direct Cost: ¥6,300,000)
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| Keywords | Enterochromaffin cell / Serotonin / VIP / Diarrhea / Paracrine secretion |
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| Research Abstract |
1.Serotonin-producing EC cells and VIP-containing nerves are distributed extensively in the digestive tract and are believed to be most importantly involved in the regulation of intestinal secretion. Double immunostaining demonstrated intimate association of the cells and the nerves.
2.Physiological expe ; riments in vivo using canine duodenal loops support the view that diarrhea is mediated by serotonin released from EC cells, which causes liveration of VIP from vicinal nerves ; both messengers working in series as well as in parallel, potentiating the effect of each other.
3.PACAP (Pituitary Adenylate Cyclase-Activating Polypeptide) was demonstrated to intensely activate ion transport in the intestinal epithelium. Enhancement by PACAP by C1^- release was shown to be an indirect effect via stimulation of cholinergic and non-cholinergic nerves.
4.Experiments using specific antagonists indicated 5-HT_3 and 5-HT_4 as the types of serotonin receptors involved in intestinal secretion.
5.SEA (Staphylococeal Enterotoxin A), previously know as causeing severe vomit, was demonstrated to cause a marked enhancement of intestinal secretion (diarrhea) in dogs ; involvement of serotonin released from EC cells was suggested by electron microscope examination of the cells.
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