Salama G, Scarpa A
J Biol Chem. 1980 Jul 25;255(14):6525-8.
The presence of diethyl ether enhances the rates of both Ca2+ uptake and ATPase activity in sarcoplasmic reticulum vesicles (SR) isolated from rabbit skeletal muscle. Stopped-flow measurements of Ca2+ transport in SR show that, in the absence of oxalate and other calcium-complexing anions, the initial velocity of the ATP-dependent Ca2+ uptake increases from 60 to 107 nmol of Ca2+/s/mg of protein when 5% (v/v) diethyl ether is present. Similar concentrations of diethyl ether increase steady state levels of Ca2+ accumulation by over 80%. Parallel to the enhancement of the rate of Ca2+ transport, diethyl ether induces an increased rate of Ca2+-dependent ATPase activity. Among four other ether compounds tested, three enhanced the rate of Ca2+ uptake, but none as effectively as diethyl ether, and a fourth reduced the rate of Ca2+ transport by the SR. These results contrast with previous observations concerning the effect of diethyl ether on ATP-dependent Ca2+ transport by SR and are now consistent with a direct pharmacological action of ether as a muscle relaxant at the level of SR Ca2+ transport.
二乙醚的存在提高了从兔骨骼肌分离出的肌浆网囊泡（SR）中Ca2+摄取速率和ATP酶活性。对SR中Ca2+转运的停流测量表明，在没有草酸盐和其他钙络合阴离子的情况下，当存在5%（v/v）二乙醚时，ATP依赖的Ca2+摄取的初始速度从60 nmol Ca2+/秒/毫克蛋白质增加到107 nmol Ca2+/秒/毫克蛋白质。类似浓度的二乙醚使Ca2+积累的稳态水平提高了80%以上。与Ca2+转运速率的提高并行，二乙醚诱导了Ca2+依赖的ATP酶活性速率的增加。在测试的其他四种醚类化合物中，三种提高了Ca2+摄取速率，但没有一种像二乙醚那样有效，第四种降低了SR的Ca2+转运速率。这些结果与先前关于二乙醚对SR的ATP依赖的Ca2+转运影响的观察结果形成对比，现在与醚作为肌肉松弛剂在SR Ca2+转运水平上的直接药理作用一致。
