| Project/Area Number |
02807008
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
General physiology
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| Research Institution | Asahikawa Mdedical College |
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Principal Investigator |
ISHIKAWA Katsushi Asahikawa, Medical College, Dept. Anatomy, Instructor, 医学部, 助手 (90125394)
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| Co-Investigator(Kenkyū-buntansha) |
OZAKI Tsuyoshi National Institute for Physiological Sciences, Associate Professor, 生理学研究所, 助教授 (20045694)
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| Project Period (FY) |
1990 – 1991
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| Project Status |
Completed (Fiscal Year 1991)
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| Budget Amount *help |
¥1,400,000 (Direct Cost: ¥1,400,000)
Fiscal Year 1991: ¥700,000 (Direct Cost: ¥700,000)
Fiscal Year 1990: ¥700,000 (Direct Cost: ¥700,000)
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| Keywords | muscularis mucasae / biphasic contraction / cholinergeic neuron / Neurokinin-A-containing neuron / electrical field stimulation / immunohistochemistry / proximal colon / guinea pig / ニュ-ロキニンーA / 潅流 / 形態 / 神経 / 運動 |
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| Research Abstract |
1)The structure, nerve supply and contractile property of the muscularis mucosas of the proximal colon in guinea pig were studied.
2)The muscularis mucosas consisted of the outer longitudinal and inner circular layers of the smooth muscles. The outer layer was well-developed.
3)The long- and narrow-shaped mitochondria were large in number in smooth muscle cells. They localized in the periphery along with the cell membrane parallel to the longitudinal axis of the cells.
4)Most of the nerve fibers supplying the muscularis mucosas faced the outer surface of the muscularis mucosas and a small number of fibers were contained within connective tissue among bundles of smooth muscle cells.
5)Small strips of muscularis mucosas with mucosa and submucosa were superfused in vitro. The strips had a spontaneous phasic contraction. The contraction was regular and rhythmic and a mean frequency was 18.8<plus-minus>0.29 contractions per minut
6)The electrical field stimulation(15 V, 0.2 msee, 20 Hz)evoked th
… More
e biphasic contraction. The first contraction abruptly appeared after a latency of a few seconds and rapidly reached the peak amplitude within 5 seconds. The second contraction gradually increased and the peak was achieved after 120-180 seconds from the start of stimulation. Both contractions were completely abolished by tetrodotoxin so that they are apparently neurogenic responses.
7)The first response was elicited cholinergically and the second was by non-cholinergic neurons, because the former was blocked by atropine but the latter was not.
8)Immunohistochemistry revealed that tachykinin-containing nerve fibers were most plentiful among several neuropeptide-containing fibers supplying the muscularis mucosas.
9)In fact, tachykinin, especially neurokinin-A, elicited a strong and slowly increased contraction under the presence of atropine. Therefore, it was considered that neurokinin-Acontaining non-cholinergic neurons caused the second contraction.
10)In conclusion, it was possible that the contraction of the muscularis mucosas of the proximal colon in guinea pig was controlled by both cholinergic and neurokinin-A-containing noncholinergic neurons. Less
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