阿托品对6种血管活性物质收缩犬离体脾动脉作用的影响

应用血管插管法观察了阿托品１μｍｏｌ·Ｌ－１对数种血管收缩物质作用的影响。去甲肾上腺素、去氧肾上腺素、５－羟色胺、组织胺、三磷酸腺苷（ＡＴＰ）及氯化钾（ＫＣｌ）可以收缩犬离体脾动脉标本，它们的收缩血管作用呈量效关系。应用１μｍｏｌ·Ｌ－１阿托品灌流脾动脉标本时，５－羟色胺、ＡＴＰ及ＫＣｌ的缩血管效应无显著变化，但是去甲肾上腺素、去氧肾上腺素及组织胺的收缩血管活性显著降低。以上结果表明，在犬离体脾动脉标本，１μｍｏｌ·Ｌ－１浓度阿托品具有抑制α肾上腺素受体激动剂及组织胺的收缩血管作用。     

吡那地尔和硝苯地平对内皮素缩血管作用的影响

目的：观察吡那地尔（Ｐｉｎ）和硝苯地平（Ｎｉｆ）对内皮素－１（ＥＴ－１）缩血管作用的影响并探讨其作用机理。方法：以ＥＴ－１在含Ｃａ２＋和不含Ｃａ２＋Ｋ－Ｈ液中预收缩离体大鼠主动脉环，比较Ｐｉｎ和Ｎｉｆ累积给药的扩血管效应。结果：在含Ｃａ２＋Ｋ－Ｈ液中，Ｐｉｎ和Ｎｉｆ均可浓度依赖性地对抗ＥＴ－１１ｎｍｏｌ·Ｌ－１的缩血管作用，ＥＣ５０分别为０．５０和０．１３μｍｏｌ·Ｌ－１。ＥＣ９５则分别为３２和３６９６μｍｏｌ·Ｌ－１。Ｐｉｎ１００μｍｏｌ·Ｌ－１可完全抑制ＥＴ－１诱发的血管收缩，相同浓度的Ｎｉｆ仅具部分抑制作用。在无Ｃａ２＋Ｋ－Ｈ液中，Ｐｉｎ１～５０μｍｏｌ·Ｌ－１亦可浓度依赖地对抗ＥＴ－１１ｎｍｏｌ·Ｌ－１的缩血管作用，其ＥＣ５０为３．８９μｍｏｌ·Ｌ－１，扩血管作用较在含Ｃａ２＋Ｋ－Ｈ液中减弱８倍。同样条件下，Ｎｉｆ未显示相应的作用。结论：ＥＴ－１的缩血管作用既与其阻断ＡＴＰ敏感性钾通道所中介的细胞外钙内流有关又涉及其激动相应受体所介导的细胞内钙释放。Ｐｉｎ和Ｎｉｆ均可对抗ＥＴ－１的缩血管作用，Ｐｉｎ的作用机制涉及其阻断电压依赖性钙通道和抑制细胞内钙释放两方面，而Ｎｉｆ的作用仅与其选择性阻断电压依赖性?     

淫羊藿总黄酮对肾上腺素能受体阻断作用的研究

淫羊藿总黄酮（ＴＦＥ，０，１３ｇ·Ｌ－１）抑制兔离体右心房肌的肌力和心率，此作用无Ｍ受体激动效应和钙拮抗作用，能使异丙肾上腺素（ＩＳＯ，１０－７ｍｏｌ·Ｌ－１）对心房肌的正性频率作用的量效曲线平行右移。ＴＦＥ不影响ＩＳＯ（１０－７ｍｏｌ·Ｌ－１）对豚鼠气管条的负性肌力作用和去甲肾上腺素（ＮＥ，１０－６ｍｏｌ·Ｌ－１）对兔主动脉条的正性肌力作用。ＴＦＥ（ｉｖ，１００ｍｇ·ｋｇ－１）明显降低麻醉猫和大鼠血压，减弱ＩＳＯ（１０μｇ·ｋｇ－１）所致的大鼠心率加快的作用，但对ＩＳＯ和肾上腺素（Ａｄｒ）的降压作用无影响，也不增敏Ａｄｒ的升压作用。实验结果证实ＴＦＥ选择性阻断离体及整体动物心肌β１受体，对气管β２受体和血管平滑肌α受体无阻断作用。     

大黄素和番泻甙A对兔主动脉收缩作用的影响

观察大黄素（Ｅｍｄ）和番泻甙Ａ（ＳｅｎＡ）对ＮＥ和高Ｋ＋诱导的兔主动脉条（ＲＡ）收缩作用的影响。结果表明，小剂量大黄素（１８．５μｍｏｌ·Ｌ－１）和番泻甙Ａ均可使ＮＥ和高Ｋ＋诱导的ＲＡ收缩的量效曲线左移，其作用原理可能与钙激动作用有关。大剂量大黄素（９２．５μｍｏｌ·Ｌ－１）抑制ＲＡ收缩作用，量效曲线右移，其作用可能与大黄素络合游离Ｃａ２＋作用有关。     

淫羊藿甙扩血管作用机制的研究

本实验以离体兔胸主动脉条为标本，对淫羊藿甙（ＥＩ）扩血管作用的机制进行了探讨。ＥＩ２０，４０ｍｇ·Ｌ－１对ＮＥ、ＫＣｌ及ＣａＣｌ２收缩兔主动脉条的量效曲线呈非竞争性拮抗作用；ＥＩ３０ｇ·Ｌ－１能明显抑制ＮＥ诱导的兔主动脉条依赖于细胞外钙的收缩反应，对依赖于细胞内钙的收缩反应没有影响；ＥＩ３０ｇ·Ｌ－１松驰主动脉条的作用与阻断α受体或激动β受体无关。提示ＥＩ的扩血管作用机制可能与其对钙通道的阻滞作用有关。     

硝普钠与异丙肾上腺素松弛犬气管平滑肌的协同作用

目的：研究硝普钠（ＳＮＰ）与异丙肾上腺素（ＩＳＯ）对犬气管平滑肌松弛作用是否存在协同关系，并分析协同的机制。方法：采用放射免疫分析法测定犬气管平滑肌环核苷酸量，并用磷酸二酯酶（ＰＤＥ）同工酶抑制剂为工具分析ＳＮＰ与ＩＳＯ相互作用的机制。结果：ＳＮＰ（１～１００μｍｏｌ·Ｌ－１）增强ＩＳＯ（３０μｍｏｌ·Ｌ－１）对３μｍｏｌ·Ｌ－１乙酰甲胆碱预收缩的犬气管平滑肌的松弛作用。ＳＮＰ（１００μｍｏｌ·Ｌ－１）与ＩＳＯ（３０μｍｏｌ·Ｌ－１）对犬气管平滑肌松弛的协同作用伴有气管平滑肌中ｃＡＭＰ积聚比ＳＮＰ与ＩＳＯ单独时分别增加１．２倍与０．４倍。ＰＤＥⅤ抑制剂扎普司特（３μｍｏｌ·Ｌ－１）使ＳＮＰ的气管平滑肌ｃＧＭＰ积聚由２．４倍增加到４．６倍，可进一步增加气管松弛作用１．２倍。合并ＰＤＥⅢ抑制剂氰胍哒嗪（３０μｍｏｌ·Ｌ－１）和ＰＤＥⅣ抑制剂咯利普兰（３０μｍｏｌ·Ｌ－１）或合并ＳＮＰ（１００μｍｏｌ·Ｌ－１）和咯利普兰（３０μｍｏｌ·Ｌ－１）均能进一步增强ＩＳＯ的气管ｃＡＭＰ积聚与松弛作用。结论：ＳＮＰ是通过气管平滑肌ｃＧＭＰ含量增加而抑制ＰＤＥⅢ，导致ＳＮＰ与ＩＳＯ对气管松弛的协同作用。     

大鼠脂肪细胞β受体亚型的研究

用异丙肾上腺素（ＩＳＯＰ）和非典型β受体激动剂ＢＲＬ３７３４４作用于大鼠脂肪细胞，测定所产生的ｃＡＭＰ含量，结果二种激动剂的量效曲线相似。ＩＳＯＰ和ＢＲＬ３７３４４的ＥＣ５０分别为２．３×１０－７ｍｏｌ·Ｌ－１和２．０×１０－７ｍｏｌ·Ｌ－１，二者的ＥＣ８０都是１０－６ｍｏｌ·Ｌ－１。在普萘洛尔（ＰＲＯＰ）和选择性β１受体阻断剂ＣＧＰ２０７１２Ａ存在的情况下，ＩＳＯＰ的作用被阻断，ＰＲＯＰ与ＣＧＰ２０７１２Ａ的ＩＣ５０分别为２．０×１０－７ｍｏｌ·Ｌ－１和５．０×１０－８ｍｏｌ·Ｌ－１。但ＰＲＯＰ及ＣＧＰ２０７１２Ａ却难以阻断ＢＲＬ３７３４４的作用，只有在很高浓度（１０－４ｍｏｌ·Ｌ－１）时才能阻断其作用。上述结果表明大鼠脂肪细胞上存在着β１受体和非典型的β受体。     

氯化汞对豚鼠心室肌电机械活动的影响

目的：观察氯化汞（ＨｇＣｌ２）对离体豚鼠乳头状肌的电生理作用。方法：采用心肌细胞内固定微电极技术。结果：ＨｇＣｌ２１～５０μｍｏｌ·Ｌ－１对豚鼠乳头状肌动作电位和收缩力的影响，具有剂量依赖性。ＨｇＣｌ２５μｍｏｌ·Ｌ－１使ＡＰＡ和Ｖｍａｘ降低，动作电位时程及ＥＲＰ缩短，心肌收缩力加强。用药物阻滞钙通道，ＨｇＣｌ２改变动作电位的ＡＰＡ，Ｖｍａｘ，ＡＰＤ。ＨｇＣｌ２１０～２０μｍｏｌ·Ｌ－１增加哇巴因诱发的震荡后电位，使触发电活动增强。结论：ＨｇＣｌ２对心脏的毒性，可能通过其使心肌细胞内钙超负荷。     

白芍总甙对大鼠腹腔巨噬细胞产生肿瘤坏死因子的调节机制

目的：研究不同浓度白芍总甙（ＴＧＰ）调节大鼠腹腔巨噬细胞（ＭΦ）产生肿瘤坏死因子（ＴＮＦ）作用。方法：在ＭΦ培养系统中有或无环氧酶抑制剂和钙调蛋白抑制剂等工具药，测定４５Ｃａ内流、ＰＧＥ２和ＴＮＦ含量。结果：ＴＧＰ（０．５～１０ｍｇ·Ｌ－１）明显促进ＬＰＳ诱导ＭΦ的４５Ｃａ内流和ＴＮＦ产生。线性回归分析表明，４５Ｃａ内流和ＴＮＦ产生呈明显正相关。三氟拉嗪（４０μｍｏｌ·Ｌ－１）可阻断ＴＧＰ促进ＬＰＳ诱导ＭΦ产生ＴＮＦ。ＴＧＰ－ＬＰＳ的ＴＮＦ释放曲线呈钟罩形，而ＴＧＰ－ＬＰＳ的ＰＧＥ２产生曲线呈浓度依赖性升高。当ＴＧＰ在低浓度（０．５～１２．５ｍｇ·Ｌ－１）时，ＴＮＦ与ＰＧＥ２产生明显正相关，而高浓度（１２．５～２５０ｍｇ·Ｌ－１）两者呈明显负相关。吲哚美辛（１０μｍｏｌ·Ｌ－１）可使ＴＮＦ量效曲线下降支消失，而Ｎω亚硝基－Ｌ－精氨酸（１５μｍｏｌ·Ｌ－１）对此无明显影响。结论：低浓度ＴＧＰ对ＴＮＦ产生上调作用可能与促进４５Ｃａ内流，提高钙调蛋白活性从而促进ＰＧＥ２分泌等有关，而高浓度下调作用是可能与ＭΦ自身产生大量ＰＧＥ２介导有关。     

前胡丙素对培养心肌细胞~（45）Ca~（2＋）摄入及细胞内游离钙的影响

利用培养的乳鼠心肌细胞测定细胞４５Ｃａ２＋的摄入及细胞内游离钙的浓度。结果表明，前胡丙素（Ｐｒａ－Ｃ）１０－１００μｍｏｌ·Ｌ－１依浓度抑制４５Ｃａ２＿的摄入，并抑制由３０μｍｏｌ·Ｌ－１ＫＣｌ所引起的４５Ｃｓ２＋摄入的增加，同时Ｐｒａ－Ｃ１００μｍｏｌ·Ｌ－１对去甲肾上腺素所诱发的４５Ｃａ２＿摄入的增加也有抑制作用。Ｐｒａ－Ｃ１０μｍｏｌ·Ｌ－１和维拉帕米１０μｍｏｌ·Ｌ－１能抑制细胞外高钾（３０，５０ｍｍｏｌ·Ｌ－１）引起的［Ｃａ２＋］ｉ的升高，同时Ｐｒａ－Ｃ３０ｍｏｌ·Ｌ－１和维拉帕米１０μｍｏｌ·Ｌ－１对去甲肾上腺素１０μｍｏｌ·Ｌ－１在无钙及含ＣａＣｌ２１．３ｍｍｏｌ·Ｌ－１的溶液中所引起的［Ｃａ２＋］，的增加也有抑制作用。提示前胡丙素对心肌细胞的作用与其阻滞钙通道有关。     

灯盏花素对人脐静脉内皮细胞胞内Ca~(2+)水平的调控作用

目的探讨灯盏花素对培养的人脐静脉内皮细胞(HUVECs)胞内Ca2+水平([Ca2+]i)的调控作用。方法采用新一代Ca2+荧光探针Fluo-3/AM标记培养的HUVECs,激光共聚焦显微镜检测细胞胞内钙荧光信号,观察灯盏花素对培养的HUVECs胞内Ca2+水平的调控作用。结果在胞外有Ca2+或无Ca2+的情况下,灯盏花素均可引起[Ca2+]i的短暂性升高;灯盏花素的Ca2+释放作用与钙泵抑制剂CPA存在着交迭;灯盏花素能够抑制由KCl所引起的[Ca2+]i的升高;灯盏花素对胞内Ca2+池耗竭后胞外复Ca2+所引起的钙内流无明显阻断作用。结论灯盏花素可引起胞内Ca2+池的Ca2+释放,其释放的Ca2+来自CPA敏感的Ca2+池。灯盏花素也可抑制经电压依赖性Ca2+通道的Ca2+内流,对Ca2+池耗竭后引起的Ca2+内流通道无明显阻断作用。     

Fendiline mobilizes intracellular Ca2+ in Chang liver cells

1. The effects of the antianginal drug fendiline (N-[3,3-diphenylpropyl]-alpha-methyl-benzylamine) on intracellular free Ca2+ levels ([Ca2+](i)) in Chang liver cells were evaluated using fura-2 as a fluorescent Ca2+ indicator. 2. Fendiline (1-100 micromol/L) increased [Ca2+](i) in a concentration-dependent manner, with an EC50 of 25 micromol/L. 3. The [Ca2+](i) response was composed of an initial rise and a slow decay to a sustained phase. Removal of extracellular Ca2+ partly reduced the [Ca2+](i) signals. 4. Fendiline (10 micromol/L)-induced release of intracellular Ca2+ was reduced by 65% following pretreatment with 1 micromol/L thapsigargin (an endoplasmic reticulum Ca2+ pump inhibitor) to deplete Ca2+ stored in the endoplasmic reticulum. 5. After pretreatment with 10 micromol/L fendiline in Ca2+-free medium for several minutes, addition of 3 mmol/L Ca2+ induced an increase in [Ca2+](i) of a magnitude four-fold greater than control. This increase in [Ca2+](i) was not reduced by 10 micromol/L SKF96365, econazole, nifedipine or verapamil. 6. Fendiline (10 micromol/L)-induced release of intracellular Ca2+ was not altered by inhibition of phospholipase C with 2 micromol/L 1-(6-((17beta-3-methoxyestra-1,3,5(10)-trien-17-yl)amino) hexyl)-1H-pyrrole-2,5-dione (U73122). 7. The results of the present study show that fendiline induces an increase in [Ca2+](i) in Chang liver cells by releasing stored Ca2+ in an inositol 1,4,5-trisphosphate-independent manner and by causing extracellular Ca2+ influx.     

Effects of econazole on Ca2+ levels in and the growth of human prostate cancer PC3 cells

1. Econazole is used clinically as an antifungal drug with many different in vitro effects. However, the effects of econazole on prostate cancer cells are unknown. The effects of econazole on intracellular Ca2+ concentrations ([Ca2+]i) in and the proliferation of human PC3 prostate cancer cells was explored in the present study using fura-2 and tetrazolium as fluorescent dyes. 2. At a concentration of 0.1 micromol/L, econazole started to increase [Ca2+]i in a concentration-dependent manner. The econazole-induced increase in [Ca2+]i was reduced by 48% by removal of extracellular Ca2+, suggesting that the econazole-induced increase in [Ca2+]i was composed of extracellular Ca2+ influx and intracellular Ca2+. 3. This econazole-induced Ca2+ influx was via an L-type Ca2+ channel-like pathway. In Ca2+-free medium, 1 micromol/L thapsigargin, an inhibitor of the endoplasmic reticulum Ca2+-ATPase, caused a monophasic increase in [Ca2+]i, after which the effect of econazole to increase [Ca2+]i was substantially inhibited. Conversely, pretreatment with 5 micromol/L econazole to deplete intracellular Ca2+ stores totally prevented thapsigargin from releasing more Ca2+. 4. The phospholipase C (PLC) inhibitor U73122 (2 micromol/L) abolished the increase in [Ca2+]i induced by 10 micromol/L ATP (a Ca2+ mobilizer that needs inositol 1,4,5-trisphosphate). 5. Overnight incubation with 1-30 micromol/L econazole inhibited proliferation of PC3 cells in a concentration-dependent manner. 6. These findings suggest that, in PC3 cells, econazole increases [Ca2+]i by stimulating Ca2+ influx into cells and Ca2+ release from the endoplasmic reticulum via a PLC-independent mechanism. Econazole is cytotoxic at submicromolar concentrations.     

Alpha 2-adrenoceptor mediated inhibition of exocytotic noradrenaline release in the absence of extracellular Ca2+.

The effect of the alpha 2-adrenoceptor agonist clonidine on 3,4-diaminopyridine (3,4-DAP)-evoked [3H]noradrenaline ([32H]NA) release in rat hippocampus slices was studied in the presence or absence (+1 mM EGTA) of extracellular Ca2+. 3H overflow (consisting mainly of unmetabolized [3H]NA) was evoked by addition of 100 microM 3,4-DAP for 10 min to the medium, which always contained 1 microM desipramine. Ligands for L-type voltage-sensitive Ca2+ channels (VSCC) did not affect the evoked [3H]NA release, whereas the preferential N-type VSCC antagonist omega-conotoxin was inhibitory, both in the presence and even more potently in the absence of Ca2+, suggesting an involvement of N-type VSCC in the mechanism of 3,4-DAP-evoked [3H]NA release. In the absence of extracellular Ca2+ the initial Na+ influx, which has been previously proposed to liberate Ca2+ from intracellular stores for the exocytotic process, most probably occurs via N-type VSCC. Clonidine inhibited the 3,4-DAP-evoked [3H]NA release in a concentration-dependent manner, both in the presence and even more potently in the absence of Ca2+; its effects were antagonized by yohimbine. In the presence of extracellular Ca2+ the clonidine effect was not changed by addition of omega-conotoxin. Similar effects of clonidine were found in slices from the rabbit hippocampus. Since the availability of Ca2+ from intracellular stores seems to predominate in the present model, our results lend some support to the suggestion that alpha 2-adrenoceptor activation might affect intracellular mechanisms of Ca2+ homeostasis.(ABSTRACT TRUNCATED AT 250 WORDS)     

蛋白酪氨酸激酶抑制剂对脑血管平滑肌细胞Ca~(2+)池操纵性Ca~(2+)内流的影响

目的　研究蛋白酪氨酸激酶和蛋白酪氨酸磷酸酶抑制剂对牛脑血管平滑肌细胞 (CSMC)Ca2 + 池操纵性Ca2 + 内流的影响。方法　采用培养的CSMC ,在生物荧光双波长影像分析系统用Fura 2 /Am荧光探针测定单个细胞内游离Ca2 + 浓度。结果　 (1)蛋白酪氨酸激酶抑制剂 (genistein ,2 5 ,5 ,10 μmol·L-1)能浓度依赖性降低内皮素 1(ET 1,10 -7mol·L-1)刺激引起的CSMCCa2 + 内流 ,抑制率分别为5 6%± 2 .9%、2 5 6%± 3 9%、48 9%± 3 7% ;蛋白酪氨酸磷酸酶抑制剂 (vanadate ,2 ,4,8μmol·L-1)能浓度依赖性升高CPA刺激引起的CSMCCa2 + 内流 ,增加比率分别为8 2 %± 3 9%、18 8%± 4 9%、46 6%± 6 9% ;(2 ) genistein(2 5 ,5 ,10 μmol·L-1)能浓度依赖性降低ATP(10 μmol·L-1)刺激引起的CSMCCa2 + 内流 ,抑制率分别为 6 7%±2 6%、2 4 6%± 6 5 %、5 1 3 %± 6 9% ;vanadate (2 ,4,8μmol·L-1)能浓度依赖性升高ATP刺激引起的CSMCCa2 +内流 ,增加比率分别为 4 8%± 2 0 %、2 8 5 %± 4 6%、49 6%± 3 3 % ;(3 ) genistein (2 5 ,5 ,10 μmol·L-1)能浓度依赖性降低环匹阿尼酸 (Cyclopiazonicacid ,CPA ,10 μmol·L-1)刺激引起的CSMCCa2 + 内流 ,抑制率分别为 6 5 %± 3 0 %、2 2 5 %± 5 2 %、     

Ca2+ influx insensitive to organic Ca2+ entry blockers contributes to noradrenaline-induced contractions of the isolated guinea pig aorta

We determined the contribution of intracellular Ca2+ to the noradrenaline (NA, 3 X 10(-5) mmol/l)-induced contraction of the isolated guinea pig aorta. Since only about 55% of the NA-induced contraction could be attributed to intracellular Ca2+ release, we assumed that a Ca2+ influx component contributes to the NA-induced contraction. This influx component proved resistant to the organic calcium entry blockers (CEBs) nifedipine, diltiazem, flunarizine and gallopamil which, in contrast, antagonized K(+)-induced Ca2+ influx completely. Conversely, the NA-induced Ca2+ influx component could be antagonized by the inorganic cations La3+, Cd2+, Mn2+, Ni2+ and Co2+. 45Ca2+ uptake experiments also revealed that both KCl and NA induce Ca2+ influx of which only the latter one is resistant to nifedipine. It was concluded that in the guinea pig aorta NA activates a receptor-operated channel through which Ca2+ can be translocated from the extracellular space to the cytosol to contribute directly to contraction.     

褪黑素对谷氨酸所致大鼠神经细胞Ca~(2+)内流的影响

目的 :研究褪黑素对谷氨酸引起的神经细胞Ca2 +内流的抑制作用。方法 :用Ca2 +敏感荧光指示剂Fura -2/AM负载大鼠脑细胞 ,测定神经细胞内游离Ca2 +浓度。结果 :谷氨酸500μmol/L可促进Ca2 +内流 ,显著增加细胞内游离Ca2 +浓度 (P<0. 01) ;应用褪黑素10 -5mol/L后可显著抑制Ca2 +内流 ,降低细胞内游离Ca2 +浓度 (P<0. 01)。结论 :褪黑素可通过抑制谷氨酸引起的Ca2 +内流保护神经细胞。     

Cl-通道阻断剂对A10细胞α1-AR介导的Ca2+内流的影响

目的 :在胚胎大鼠主动脉平滑肌细胞 (A10 ) ,探讨Cl- 通道与Ca2 + 内流的关系及酪氨酸磷酸化对Ca2 + 内流的作用。方法 :采用Fura 2荧光探针双波长测定胞浆游离Ca2 + 浓度 ([Ca2 + ]i)。结果 :Ca2 +通道阻断剂nifedipine和SK&F96 36 5可阻止肾上腺素 (Adr)触发的Ca2 + 内流 ;氯通道阻断剂niflumicacid(NFA)和furosemide呈浓度依赖性抑制Ca2 + 内流。在Ca2 + 内流被SK&F96 36 5最大限度抑制后 ,NFA和furosemide可进一步抑制Ca2 + 内流 ;而Ca2 +内流被NFA和furosemide分别最大抑制 2 8%和 35 %后 ,SK&F96 36 5也可进一步抑制Ca2 + 内流达 5 3%和5 2 %。genistein呈浓度依赖性抑制Ca2 + 内流 ;vana date浓度依赖性促进Ca2 + 内流。结论 :在A10细胞 ,肾上腺素受体触发的Ca2 + 内流涉及电压依赖性Ca2 + 通道 (VDC)和受体操纵性Ca2 + 通道 (ROC) ;氯通道参与了VDC及ROC介导的Ca2 + 内流 ;蛋白酪氨酸磷酸化的水平影响Ca2 + 内流。     

Effects of pincainide on contractile responses and 45Ca movements in rat isolated vascular smooth muscle

The effects of pincainide, a new beta-amino anilide, on contractile responses and 45Ca fluxes were studied in rat aorta and on spontaneous mechanical activity in rat portal veins. Pincainide (10(-5) to 10(-2) M) produced a dose-dependent inhibition of noradrenaline (NA) and high K+ -induced contractions. These inhibitory effects were observed with pincainide added either before or after the induced contractions. The Ca2+ -induced contractions of K+ -depolarized aorta as well as the spontaneous mechanical activity of portal veins were also inhibited by pincainide. Pincainide (5 X 10(-3) M) inhibited the 45Ca influx stimulated by 10(-6) M NA and increased 45Ca efflux. It was concluded that in isolated rat aorta, pincainide not only inhibited the influx of Ca2+ reducing the contractile responses to NA and high K+ but it also inhibited other effects related to NA-induced release of intracellular Ca2+ stores.     

大鼠主动脉α_1肾上腺素能受体激活引起Ca~（2＋）内流的特性

在大鼠主动脉平滑肌标本上，０．５μｍｏｌ．Ｌ－１硝苯吡啶能完全阻断由１００ｍｍｏｌ·Ｌ－１ＫＣｌ引起的血管收缩和４５Ｃａ内流；并部分抑制苯肾上腺素引起的血管收缩效应和４５Ｃａ内流；６ｍｍｏｌ·Ｌ－１普鲁卡因能完全阻断无钙Ｋｒｅｂｓ液中苯肾上腺素引起的血管收缩和４５Ｃａ外溢，且部分阻断正常Ｋｒｅｂｓ液中苯肾上腺素引起的血管收缩和４５Ｃａ内流；０．５μｍｏｌ·Ｌ－１硝苯吡啶和６ｍｍｏｌ·Ｌ－１普鲁卡因合用能阻断苯肾上腺素引起的Ｃａ２＋内流。提示：α１受体兴奋后引起的细胞外Ｃａ２＋内流可分为硝苯吡啶敏感和不敏感两部分，而后者受细胞内Ｃａ２＋释放调节。