open access

https://hdl.handle.net/2115/68633

アドレナリンα2A受容体サブタイプに対するα2作動薬の作用に関する研究 [全文の要約]

日本語

2017-03-23

Hokkaido University

https://www.lib.hokudai.ac.jp/dissertations/copy-guides/

α2-Adrenoceptor (AR) agonists, dexmedetomidine (DEX) and xylazine (XYL), are clinically used for sedation and analgesia in humans and animals. The effect of xylazine shows marked species difference. α2A-AR subtype is reported to be important for the effect of α2-AR agonist, but precise mechanism of action of α2-AR agonists is still unclear. The effect of DEX and XYL by using functional α2A-AR KO mice (D79N) was estimated. In the isolated spinal cord preparation of mice, DEX and XYL inhibited both slow ventral root potential (sVRP), which is thought to reflect a nociceptive pathway, and monosynaptic reflex potential (MSR). sVRP was more sensitive to these agonists than MSR. sVRP inhibitions by DEX and XYL were attenuated in D79N mice. sVRP inhibition by DEX in D79N mice was reversed by atipamezole (α2-AR antagonist), but not by JP1302 (α2C-AR antagonist), efaroxan (imidazoline I1 receptor antagonist) nor idazoxan (I2 antagonist). sVRP inhibition by XYL in D79N mice was not reversed by atipamezole, JP1302, efaroxan nor idazoxan. XYL but not DEX suppressed the conduction of compound action potential in the spinal nerves. These results indicate that α2A-AR plays an important role in sVRP inhibition by DEX and XYL. XYL also inhibits conduction of action potential at its high concentrations, which is not mediated by α2A-AR.

甲第12616号

博士(獣医学)

(主査) 准教授 乙黒 兼一, 教授 木村 和弘, 教授 石塚 真由美, 名誉教授 伊藤 茂男

獣医学研究科（獣医学専攻）

博士論文

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