2002 Fiscal Year Final Research Report Summary
Study for autonomic response induced by emetic stimuli and their central neural mechanisms in rats
| Project/Area Number |
13671937
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| Research Category |
Grant-in-Aid for Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Section | 一般 |
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| Research Field |
Functional basic dentistry
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| Research Institution | OKAYAMA UNIVERSITY |
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Principal Investigator |
KOBASHI Motoi Graduate School of Medicine and Dentistry, Oral Physiology, Associate Professor, 大学院・医歯学総合研究科, 助教授 (80161967)
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| Co-Investigator(Kenkyū-buntansha) |
TSUKAMOTO Goichi Graduate School of Medicine and Dentistry, Oral Physiology, Assistant Professor, 大学院・医歯学総合研究科, 助手 (40263610)
MATSUO Ryuuji Graduate School of Medicine and Dentistry, Oral Physiology, Professor, 大学院・医歯学総合研究科, 教授 (30157268)
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| Project Period (FY) |
2001 – 2002
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| Keywords | apomorphine / gastric motility / vagal nerve / submandibular salivary secretion / neurokinine-1 / rats / vomiting / nausea |
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| Research Abstract |
The effects of apomorphine administration on the autonomic responses were investigated in rats. Distinctive gastric motor responses were observed after the intravenous administration of apomorphine (0.1 mg/kg body wt). Gastric motor responses in the distal stomach induced by apomorphine administration were classified into two types. One type involved inhibition of phasic contractions which appeared just after the administration of apomorphine. The other involved an increase in the frequency of small phasic contractions accompanied by increased gastric tone appearing with a relatively longer delay. No relaxation was observed in either the proximal or distal stomach. These gastric motor responses showed a dose-response effect to the amount of apomorphine administered (0.002 - 0.1mg/kg body wt). In addition, submandibular salivary secretion was observed in response to the intravenous administration of apomorphine at a dose of 3 or 10 mg/kg body wt. Pre-treatment with domperidone (1 or 2 m
… More
g/kg body wt) or the ablation of the area postrema (AP) abolished the gastric motor response and salivary secretion induced by the administration of apomorphine. In conclusion, rats showed definitive autonomic phenomena in response to the administration of apomorphine. Dopamine 2-like receptors situated in the AP mediate apomorphine-induced autonomic phenomena in rats. Pretreatment of intravenous NK-1 antagonist diminished the increase in intragastric pressure, dose-dependently. Microinjection of NK-1 antagonist into the vicinity of the nucleus ambiguus (NA) did not influence on the inhibitory response of the phasic contractions but diminished the increase in intragastric pressure. Microinjection of neurotoxic agents, ibotenic acid dissolved in pontamine sky blue solution, into the same area also diminished the increase in intragastric pressure. In conclusion, increase in intragastric pressure, which appeared with relatively longer delay after the apomorphine administration, may be mediated by NK1 receptors in the vicinity of the NA. Less
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Research Products
(10 results)
