| Project/Area Number |
04670116
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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 pharmacology
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| Research Institution | Osaka University |
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Principal Investigator |
KURODA Masao Osaka University, Faculty of Medicine, Department of Central Laboratory, 医学部, 講師 (90028556)
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| Co-Investigator(Kenkyū-buntansha) |
FUKUI Hiroyuki Osaka University, Faculty of Medicine, Department of Pharmacology II, Associate, 医学部, 助教授 (90112052)
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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 |
¥2,100,000 (Direct Cost: ¥2,100,000)
Fiscal Year 1993: ¥1,100,000 (Direct Cost: ¥1,100,000)
Fiscal Year 1992: ¥1,000,000 (Direct Cost: ¥1,000,000)
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| Keywords | astrocytes / neurotransmitter / receptor / histamine / prostaglandin / acetylcholine / cloning / astrocytoma / ヒスタミンH_1受容体 / ヒスタミン神経 / グリコーゲン / 転写機構 / プロスタグランジン / カルシウム / イノシトールリン酸 / サイクリックAMP |
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| Research Abstract |
We found that promary cultured astrocytes expressed for various neurotransmitters, and suggested that astrocytes were target for neurons. Primary cultured. Histamine fumctions as a neurotransmitter through histamine H_1 and H_2 receptor subtypes. Type-1 astrocytes expressed H_2 receptor subtype, and type-2 expressed H_1 receptor subtype, although m3 muscarinic acetylcholine receptors were expressed in both cells. Prostaglandins act as neuroactive sabstances, and FP and EP receptor subtypes were expressed in thpe-1 astrocytes and type-2 astrocytes, respectively. Every astrocytes differently responded to various neuroactive substances. These results indicate that cultures astrocytes playd heterogeneous functions. Glycogen storage and glucose supply are a major function of astrocytes. Rat C6 astrocytoma cells have been used for the investigation of glycogen metabolism. We established C6 astrocytoma cells (C6-H1R cells) stably expressed the cloned histamine H_1 receptors by the transfection of the H_1 receptor cDNA.The accumulation of inositol phosphates and the elevation of intracellular free calcium ion concentration were induced after the stimulation of C6-H1R cells by histamine. The stimulation of the cells by histamine did not influence the level of cyclic AMP.These results indicate the absence og the crosstalk between inositol phosphates and cyclic AMP signalings in the cells. By in situ hybridization using H_1 receptor mRNA.We also found that the transcription of the histamine H_1 receptor gene in the central nervous system was differnt from that in peripheral tissues, and that [^3H]mepyramine labeled not only H_1 receptors but also a family protein of cytochrome P450 IID in the contralmervous system.
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