アブストラクト(24巻3号:神奈川歯学)

神奈川歯学

Japanese

Title : 咬筋小胞体カルシウム輸送系に対するCompound 40 / 80 の効果
Subtitle : 原著
Authors : 小田島千里, 伊藤春生
Authors(kana) :
Organization : 神奈川歯科大学歯科薬理学教室
Journal : 神奈川歯学
Volume : 24
Number : 3
Page : 431-439
Year/Month : 1989 / 12
Article : 原著
Publisher : 神奈川歯科大学学会
Abstract : 「緒言」咬筋から単離された筋小胞体(SR)によるATP依存性Ca2+ uptakeは, 心筋同様Ca2+によって活性化されるATP加水分解と化学量論的に強く共役している. しかし, Okabe et al. は心筋SRを用いた場合, calmodulin依存性反応を抑制することでCa2+ uptakeとATP加水分解との共役がはずれることを見い出し, これをcalmodulin制御性Ca2+ チャンネルからのCa2+ 放出増大の結果であると推測した. 細胞機能のCa2+ 依存性反応過程の制御に果たすcalmodulinのセカンドメッセンジャーとしての役割について, 広範な研究が展開されている. Ca2+ 存在下でcalmodulinは, phosphodiesterase, adenylate cyclase, ミオシン軽鎖kinase, および赤血球や心臓の細胞膜Ca2+, Mg2+ -ATPase, など多くの酵素系を制御しており, とくに, 細胞内Ca2+ 濃度を一定に維持するための細胞膜を介する能動的Ca2+ 押し出し機構(Ca2+ ポンプ)の活性化に密接に関与している.
Practice : 歯科学
Keywords : 咬筋小胞体, compound 48/80, calmodulin, Ca2+ permeability, Ca2+ チャンネル

English

Title : Effect of Compound 48 / 80 on Masseter Muscle Sarcoplasmic Reticulum Calcium Transport System
Subtitle : Original article
Authors : Chisato ODAJIMA, Haruo Ito
Authors(kana) :
Organization : Department of Pharmacology, Kanagawa Dental College
Journal : Kanagawa Shigaku
Volume : 24
Number : 3
Page : 431-439
Year/Month : 1989 / 12
Article : Original article
Publisher : Kanagawa Odontological Society
Abstract : Abstract : To define the role of calmodulin in Ca2+ fluxes behavior of canine masseter muscle sarcoplasmic reticulum (SR) vesicles, the effect of condensation product of N-methyl-p-methoxyphenethylamine with formaldehyde (compound 48/80), a selective and powerful inhibitor of calmodulin-regulated function, on Ca2+ -ATPase activity, oxalate-supported Ca2+ uptake velocity, and on interaction with Ca2+ permeability and Ca2+ loading at steady-state were evaluated. Compound 48/80, at concentrations of 10 to 100μg/ml, reduced oxalate-supported Ca2+ uptake velocity without affecting Ca2+ -ATPase activity. In the presence of 10μg/ml compound 48/80, there was a sift of pH- or temperature-response curve of oxalate-supported Ca2+ uptake velocity, but not of Ca2+ -ATPase activity, down. It was found that Arrhenius plots of the Ca2+ -ATPase activity show a break at about 21°C in the presence or absence of 10μg/ml compound 48/80, and that compound 48/80 has no effect on Arrhenius plots of the oxalate-supported Ca2+ uptake velocity. Furthermore, Ca2+ loading at steady-state, but not passive Ca2+ permeability, was decreased by compound 48/80 at low concentrations (1-2μg/ml). The results of this study suggest that calmodulin-dependent process plays a functional role in the coupling of ATP hydrolysis and Ca2+ accumulation, perhaps through regulation of Ca2+ release channels in masseter muscle SR membrane. Calmodulin-dependent component of Ca2+ fluxes in the SR vesicles may be directly modified by compoumd 48/80, thereby diminishing Ca2+ accumulation without affecting the Ca2+ uptake mechanism.
Practice : Dentistry
Keywords :