1991 Fiscal Year Final Research Report Summary
Immunohistochemical and ultrastructural study of GRP-containing nerves in the gastric mucosa
| Project/Area Number |
02454111
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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) |
KANAZAWA Hiroaki Niigata University, School of Medicine, Assistant, 医学部, 助手 (40214431)
IWANAGA Hiromi Niigata University, School of Medicine, Assistant, 医学部, 助手 (30193759)
IWANAGA Toshihiko Niigata University, School of Medicine, Associate Prof., 医学部, 助教授 (10160128)
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| Project Period (FY) |
1990 – 1991
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| Keywords | GRP / Gastrin-releasing peptide / Immunohistochemistry / Gastric mucosa / Peptic ulcer / Microcirculation / Autonomic neurons / Brain-gut hormones |
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| Research Abstract |
1. Innervation of the oxyntic mucosa : The gastric mucosa of mammalian species is heavily innervated by several types of peptidergic nerve fibers : gastrin-releasing peptide (GRP)-containing nerves being most predominant among them. Cholinesterase-positive nerves were densely distributed in the rat gastric mucosa and identical to the GRP nerves, while adrenergic nerves were few.
2. Ultrastructure of GRP-containing nerves : The immunoreactivity for GRP was selectively localized in large cored vesicles gathering in the swollen parts of nerve fibers. Numerous small clear vesicles free of the immunoreactivity were interm : Engled with the large cored vesicles, suggesting the colocalization of GRP and other transmitter with a small molecular weight, possibly acetylcholine.
3. Stress-induced morphological change of GRP nerves : The decreased GRP immunoreactivity in the nerves was ultrastructurally confirmed by the present observation showing marked decrease in number of the GRP-containing large cored vesicles. Simultaneously, small clear vesicles decreased in number, suggesting the corelease of GRP and acetylcholine under stress condition.
4. Topographic relation of GRP nerves and blood vessels : The GRP nerves were shown under SEM to be closely related with capillaries, but not with any glandular cells. The capillaries were accompanied by pericytes which are contractile in nature, thus being able to contract, finally causing mucosal ischemia and damage. Arterioles around the lamina muscularis mucosas might be also important in regulation of blood flow, since they suppiyed the mucosal capillaries in the lamina propria and were densely innervated by vasomotor neurons.
5. Mast cells in the gastric mucosa : Mast cells in rodents contain serotonin as well as histamine. However, they in the gastric mucosa did not possess a synthesizing enzyme for serotonin, in contrast to peritoneal mast cells.
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