A23187 increases calcium permeability of store sites more than of surface membranes in the rabbit mesenteric artery.
A23187 increases calcium permeability of store sites more than of surface membranes in the rabbit mesenteric artery.
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A23187 增加兔肠系膜动脉钙储存位点的钙渗透性，其效果大于表面膜的钙渗透性。
DOI：
10.1113/jphysiol.1985.sp015597
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发表时间：
1985
期刊：
影响因子：
--
通讯作者：
H. Kuriyama
中科院分区：
文献类型：
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作者：
T. Itoh;Y. Kanmura;H. Kuriyama
研究了钙离子载体A23187对家兔肠系膜动脉完整和去皮平滑肌组织的作用。A23187（超过10（-9）M）以剂量依赖性方式抑制10（-5）M-去甲肾上腺素（NA）或10 mM-咖啡因在含2 mM-EGTA的无Ca 2+溶液中诱导的收缩。在存在或不存在Ca 2+的情况下，丙酸（3 mM）导致咖啡因或NA诱导的收缩停止。当应用A23187（10（-7）M）时，在普鲁卡因存在下的收缩在一定程度上恢复在Krebs溶液中。浓度为10（-7）M的A23187没有改变静息肌张力，但该浓度确实增加了20.2或128 mM-K+诱发的收缩幅度，并显著抑制了Krebs溶液中10（-7）M-NA或10 mM-咖啡因诱发的收缩。A23187（10（-7）M）延迟了10（-5）M-NA-诱导收缩的起始和上升相，并抑制振荡收缩。高浓度的A23187（超过10（-6）M）在存在的情况下产生较大的收缩，在不存在2.6 mM-Ca 2+的情况下产生较小的收缩。这些A23187诱导的收缩不受10（-7）M-尼索地平（一种Ca 2+拮抗剂）的抑制。长期应用A23187（超过10（-6）M）使肌肉组织功能性皮肤化。然而，A23187处理的带皮肌肉的Ca 2+敏感性低于皂苷处理的肌肉。在皂苷处理的带皮肌肉中，A23187（低于10（-6）M）对pCa-张力关系无影响。在填充储存器后，A23187（超过10（-7）M）在存在或不存在5 mM-NaN 3的情况下产生比无Ca 2+溶液中的咖啡因更大的收缩。当10（-7）M-A23187应用一次5分钟时，随后应用咖啡因（20 mM），在应用Ca 2+之后，不再产生皮肤肌肉组织的收缩。目前的结果表明，低浓度的A23187显示出对肌细胞中Ca 2+储存位点的选择性Ca 2+释放作用，高浓度的A23187增加了Ca 2+渗漏（内流），细胞膜被剥皮。
The effects of a Ca ionophore, A23187, were investigated on intact and skinned smooth muscle tissues of the rabbit mesenteric artery. A23187 (over 10(‐9) M) inhibited, dose dependently, contractions induced by 10(‐5) M‐noradrenaline (NA) or 10 mM‐caffeine in Ca2+‐free solution containing 2 mM‐EGTA. Procaine (3 mM) led to cessation of the caffeine‐ or NA‐induced contractions in the presence or absence of Ca2+. When A23187 (10(‐7) M) was applied, the contractions in the presence of procaine were to some extent restored in Krebs solution. A23187 at a concentration of 10(‐7) M did not modify the resting muscle tone, but this concentration did increase the amplitude of the contraction evoked by 20.2 or 128 mM‐K+ and markedly inhibited the 10(‐7) M‐NA or 10 mM‐caffeine‐induced contraction in Krebs solution. A23187 (10(‐7) M) delayed the onset and rising phase of the 10(‐5) M‐NA‐induced contraction with inhibition of the oscillatory contractions. High concentrations of A23187 (over 10(‐6) M) produced a large contraction in the presence and a small contraction in the absence of 2.6 mM‐Ca2+. These A23187‐induced contractions were not inhibited by 10(‐7) M‐nisoldipine, a Ca2+ antagonist. A23187 (over 10(‐6) M) applied for a long period functionally skinned the muscle tissues. However, the Ca2+ sensitivity of the A23187‐treated skinned muscles was lower than that of saponin‐treated muscles. In saponin‐treated skinned muscles, A23187 (below 10(‐6) M) had no effect on the pCa‐tension relation. After filling the store, A23187 (over 10(‐7) M) generated a larger contraction than did caffeine in Ca2+‐free solution, in the presence or absence of 5 mM‐NaN3. When 10(‐7) M‐A23187 was applied once for 5 min, subsequently applied caffeine (20 mM), following application of Ca2+, no longer produced contraction of skinned muscle tissues. The present results indicate that low concentrations of A23187 show a selective Ca2+‐releasing action on Ca2+ store sites in muscle cells and that high concentrations increase the Ca2+ leakage (influx) and the cell membrane is skinned.
地尔硫卓和某些其他 Ca2 拮抗剂药物选择性抑制 Na 诱导的心脏线粒体 Ca2 释放。
DOI：
--
发表时间：
1982
期刊：
The Journal of biological chemistry
影响因子：
--
作者：
Vághy,PL;Johnson,JD;Matlib,MA;Wang,T;Schwartz,A
通讯作者：
Schwartz,A