硫酸锌对心肌慢反应电活动和哇巴因引起振荡后电位的影响

本文目的旨在观察硫酸锌对心肌慢反应电活动的影响,所得结果如下:(1) 0.1～0.3mmol硫酸锌能使高钾除极引起的豚鼠乳头肌慢反应动作电位APA和V_max降低,APD₅₀和APD₉₀)显著延长;(2) 0.1～0.3 mmol硫酸锌能抑制家兔离体窦房结细胞的自律性,使窦房结APA降低,APD₉₀延长,SP₀和SP₄减小;(3) 0.1 mmol硫酸锌可对抗0.4μmol哇巴因诱发的豚鼠心室肌振荡后电位,提高引起振荡后电位的哇巴因阈浓度。提示:锌抑制心肌慢反应电活动。     

桂枝油对兔离体肠平滑肌的运动作用机制

目的:观察桂枝油对兔离体肠平滑肌的肌张力影响变化,探讨桂枝油治疗肠易激综合征的作用机制。方法:采用兔离体肠平滑肌肌条,用BL-410生物机能实验系统肌张力传感器测量肌条收缩与舒张的幅值。结果:桂枝油高剂量能抑制兔离体肠平滑肌自律性肌张力,收缩张力(g)由(4.9±0.8)降至(4.0±0.4),差异有显著性(P<0.01);抑制由乙酰胆碱,组胺和氯化钡所致的兔离体肠痉挛性收缩,高中低各剂量组经统计学分析,差异有显著性(P<0.01)。结论:桂枝油能降低细胞内钙的释放,可能是由于阻滞Ca2+通过L-型Ca2+通道进入细胞内,最终使细胞内钙降低,平滑肌舒张而达到解除肠易激综合征引起的胃肠疼痛。     

氯哌胺对15-甲基前列腺素F_(2α)致泻和兴奋子宫作用的影响

氯哌胺(Loperamide)是一种新型止泻药,能拮抗15-M-PGF_(2α)引起的小鼠小肠内碳粉推进加速和腹泻,作用比吗啡和阿托品强,对离体大鼠回肠的抑制作用也比吗啡、阿托品强。氯哌胺能降低肠平滑肌张力,抑制离体大鼠回肠对15-M-PGF_(2α)的反应性,但却增强子宫平滑肌对15-M-PGF_(2α)的反应性。氯哌胺对离体大鼠子宫自发收缩活动低浓度兴奋、高浓度抑制。氯哌胺对15-M-PGF_(2α)促进大鼠空肠水和钠离子分泌也有拮抗作用,此作用不能被纳洛酮翻转。氯哌胺在小鼠的急性半数致死量为77.9 mg/kg。     

牛磺酸镁抗豚鼠离体心脏2型短QT综合征作用的研究

目的观察牛磺酸镁配合物(taurine-magnesium coordination compound,TMCC)对豚鼠离体心脏表面心电图的影响,初步探索TMCC抗2型短QT综合征(type 2 short QT syndrome,SQT2)的作用。方法采用Langendorff主动脉逆行灌流法对豚鼠离体心脏进行灌流,利用Biopac生理记录仪采集豚鼠离体心脏表面Ⅱ导联心电图以观测TMCC在应用吡那地尔(pinacidil)诱导SQT2条件下,对豚鼠离体心脏QT间期、有效不应期、跨室壁复极离散度、RR和QT间期不稳定性等的影响。结果 TMCC能够逆转吡那地尔所致QT间期的缩短,逆转吡那地尔所致有效不应期的缩短,降低吡那地尔所致的跨室壁复极离散度增大,减小吡那地尔所致的RR、QT间期不稳定性增大。结论 TMCC通过延长QT间期和有效不应期、降低跨室壁复极离散度和不稳定性等作用对SQT2有一定治疗作用。     

神经生长因子对小鼠突触体内Ca2+水平的调节作用

观察了多次海马内微注射NGF对小鼠突触体内游离钙水平的影响,并在离体情况下观察NGF对EGTA和CaCl₂分别造成突触体内低钙和高钙状态的调节作用。结果如下:(1)在体实验表明,一定剂量的NGF可显著降低老年小鼠海马突触体内游离钙水平(P<0.05);(2)离体实验表明,当突触体游离钙水平降低时,适当剂量的NGF具有升高游离钙水平的作用;而突触体内游离钙水平升高时,则NGF有降低游离钙水平的作用。提示NGF对游离钙水平的双向调节作用可能是NGF改善老年性记忆衰退的作用机制。     

门冬氨酸钾镁对离体灌流心脏缺氧的保护作用

目的探讨门冬氨酸钾镁对离体心脏缺氧的保护作用,及2种不同制剂组成方式的门冬氨酸钾镁注射液的效能比较。方法将60只SD大鼠取心脏行Langendorff离体心脏灌流,依照灌流液中钾、镁组成的不同分为A制剂组(门冬氨酸钾 门冬氨酸镁)、B制剂组(天门冬氨酸 氧化镁 氢氧化钾)及对照组(KCl MgSO4)3组,每组各20只动物,3组的K 、Mg2 等剂量。记录离体大鼠心脏在缺氧条件下的HR、左室压力变化及心脏跳动持续时间。结果A制剂组中离体心脏在缺氧后HR及左室压力降低速度缓慢,心脏跳动持续时间达(273.9±65.2)min,与B制剂组(174.7±43.6)min及对照组(121.8±32.9)min相比明显延长(P<0.01)。结论门冬氨酸钾镁液对离体缺氧心脏有保护作用,明显延长缺氧状态下心脏的跳动时间,但制剂B比制剂A的抗缺氧效能差。     

脂质体携载前列腺素E_1对心血管系统保护作用的实验研究

目的比较脂质体携载前列腺素E1(L-PGE1)和游离前列腺素E1(F-PGE1)对心血管系统保护作用(包括对血管舒张作用及对血小板聚集抑制作用)的影响。方法观察L-PGE1及F-PGE1对大鼠离体灌流的动脉条血管舒张作用的影响和对离体血小板聚集的影响。结果L-PGE1对离体血管的舒张作用较F-PGE1最大舒张增加7倍,舒张时间明显延长;L-PGE1对离体血小板聚集较F-PGE1显著降低(P<0.05)。结论L-PGE1可抑制血小板聚集、防止血栓进一步扩大及扩张血管、降低血压、增加脏器的血流灌注,对保护心血管系统具有良好的临床意义。     

青藤碱对吗啡依赖小鼠、大鼠及豚鼠离体回肠催促戒断反应的影响

目的 :研究青藤碱 (sinomenine ,SIN)对吗啡依赖小鼠、大鼠及豚鼠离体回肠催促戒断反应的抑制作用。方法 :连续递增sc吗啡 (morphine ,Mor) ,建立大鼠、小鼠及豚鼠吗啡身体依赖性模型 ;纳洛酮 (naloxone,Nal)催促诱发吗啡身体依赖性豚鼠离体回肠的戒断性收缩。结果 :(1)SIN 14.3 - 143mg·kg- 1 显著抑制纳洛酮催促后 3 0min内小鼠的跳台次数 ;(2 )SIN 10 0mg·kg- 1 降低纳洛酮催促后 1h内大鼠的戒断症状分值及抑制体重下降 ;(3 )SIN(1.5×10 - 4 - 6.0× 10 - 4 mol·L- 1 )剂量依赖性地抑制纳洛酮催促诱发的吗啡身体依赖性豚鼠离体回肠的戒断性收缩 ;(4)吗啡身体依赖性豚鼠ipSIN(87.0和 8.7mg·kg- 1 )后 ,其离体回肠经纳洛酮催促诱发的戒断性收缩幅值显著降低。结论 :SIN对吗啡身体依赖性大鼠、小鼠的戒断症状及豚鼠离体回肠的戒断性收缩具有抑制作用     

粉防己碱对小鼠、家兔和豚鼠肠平滑肌的作用

目的　研究钙拮抗剂粉防己碱 (tetrandrine,Tet)对小鼠、家兔和豚鼠肠平滑肌的影响。方法　用小鼠胃肠推进运动法 ,家兔和豚鼠离体肠平滑肌标本。结果　 Tet(1 0～ 1 5 mg· kg-1,ig)对小鼠肠平滑肌运动无明显影响 ,Tet抑制家兔离体回肠自发性收缩 ,Tet(1 0 μmol·L-1)抑制氨甲酰胆碱诱导的豚鼠结肠带依内钙收缩 ,但不影响依外钙收缩。Tet浓度依赖性地使 KCl引起的豚鼠离体结肠带收缩量效曲线非平行右移 ,最大反应降低 ,p D2 为 4.0 1。结论　 Tet主要抑制肠平滑肌电压依赖性钙通道 (PDC) ,阻止 Ca2 + 通过 PDC,但对胃肠运动功能影响较小     

葛根注射液抗心肌缺血作用药理研究

目的 考察葛根注射液的抗心肌缺血作用。方法 考察葛根注射液高中低剂量组对大鼠离体心脏左室峰压(LVSP)、冠脉流量(CF)及大鼠离体心脏缺血再灌注后的LVSP、左室舒张期末压(LVEDP)、心率(HR)、CF的影响。结果 葛根注射液可升高大鼠离体心脏心肌收缩力及冠脉流量;对离体心脏缺血再灌注导致的LVSP和LVEDP的升高、心率及冠脉流量的降低均有对抗作用。结论 葛根注射液具有抗心肌缺血的作用。     

雌酚酮衍生物EA204对离体兔血管平滑肌的舒张作用

目的探讨雌酚酮衍生物(EA204)对离体兔血管平滑肌的作用及其机制。方法以离体兔主动脉条为标本,观察了EA204对去甲肾上腺素(NE)、氯化钾(KCl)引起的兔主动脉条收缩的影响;对氯化钙(CaCl2)累积收缩量效曲线的影响,并与维拉帕米(Ver)相比较。通过对比格列苯脲(10μmol.L-1)孵育前后EA204对BaCl2、KCl的舒张量效曲线,研究EA204对钾通道的作用。结果EA204(10~3 mmol.L-1)可以剂量依赖性地抑制NE、KCl收缩的兔主动脉条;EA204(10μmol.L-1)或Ver(0.1μmol.L-1)都使CaCl2累积收缩量效曲线呈剂量依赖性右移,但EA204孵育后CaCl2量效曲线最大反应基本不变,而Ver使最大反应降低;加入格列苯脲(10μmol.L-1)孵育后EA204对BaCl2、KCl收缩的主动脉条的舒张量效曲线发生明显变化,EA204的舒张作用被抑制。结论EA204具有舒张离体兔血管平滑肌的作用,其作用机制与其钙通道阻断作用和钾通道开放作用有关。     

双氢杨梅树皮素对兔胸主动脉条平滑肌收缩反应的影响

用兔胸主动脉条研究双氢杨梅树皮素对去甲肾上腺素（NE）、KCl和CaCl2所致兔胸主动脉条收缩反应量效曲线的影响。双氢杨梅树皮素能显著地抑制NP、KCl和CaCl2所致兔胸主动脉杂的收缩，量效曲线右移，最大反应降低，对高K 所致兔胸主动脉条收缩的抑制作用明显大于NE所致兔胸主动脉条收缩的抑制作用。双氢杨梅树皮素对NE引起的依赖内Ca2 释放的收缩有明显抑制作用，而对NE依赖细胞外Ca2 性收缩区在较高浓度时才显示抑制作用，提示双氢杨梅树皮素可能对电压依赖性钙通道（PDC）有选择性阻滞作用。     

螺内酯对离体大鼠胸主动脉环舒张功能的作用和机制

目的研究螺内酯(spironolactone,SPT)对离体血管平滑肌张力影响,同时探讨SPT的作用机制。方法离体血管平滑肌张力记录法,应用SPT,观测其对Sprague Dawley(SD)大鼠离体胸主动脉环的作用及不同工具药的影响。结果 SPT对KCl(30 mmol.L-1)和NE(1μmol.L-1)预收缩的血管环具有浓度依赖的舒张作用,对内皮完整和去内皮血管环舒张作用无差异,该舒张作用为非内皮依赖性。Na+/H+交换阻滞剂氨氯吡咪(amiloride,AM,1μmol.L-1)对SPT的舒血管作用有抑制作用。在KCl预收缩基础上,加入钾通道阻断剂氯化钡(BaCl2,2μmol.L-1)、四乙胺(TEA,0.2 mol.L-1)、四氨基吡啶(4-AP,1 mmol.L-1)均不能抑制SPT的舒血管效应,ATP敏感钾通道(KATP)格列苯脲(Gli,10μmol.L-1)能抑制SPT对血管的舒张作用。在无钙的生理盐溶液中,SPT对CaCl2收缩血管有明显抑制作用。结论 SPT舒张血管的作用具有浓度依赖性,其作用机制可能与抑制Na+/H+交换、ATP敏感钾通道(KATP)以及钙离子内流有关。     

Effects of nonsteroidal antiestrogens in the in vitro rat uterus.

We have studied the effect of nonsteroidal antiestrogens on rat uterine contractions induced by oxytocin (8 nmol/l), methacholine (10 mumol/l), prostaglandin F2 alpha (1 mumol/l), KCl (60 mmol/l) and CaCl2 (6 mmol/l). In a concentration-dependent way, the antiestrogens tamoxifen, clomiphene, nafoxidine and ethamoxytriphetol inhibited the amplitude and frequency of the oxytocin-induced contractions and the contraction produced by CaCl2. At a concentration of 30 mumol/l the four drugs inhibited the contractions induced by methacholine and prostaglandin F2 alpha. They also relaxed the tonic contraction to KCl in a concentration-dependent way. This action was partially counteracted by CaCl2 (0.1-10 mmol/l). Bay k 8644 (0.3 nmol/l to 3 mumol/l) only partially reversed the inhibition by ethamoxytriphetol (0.1 mmol/l) of CaCl2 (6 mmol/l)-induced contractions. The steroidal antiestrogen, ICI 164,384, which lacks agonist activity, had an inhibitory effect (44 +/- 4%, n = 7) on KCl-induced contractions only at a concentration of 0.1 mmol/l. However, the quaternary analogue of tamoxifen (tamoxifen ethyl bromide) produced 86 +/- 3% relaxation of the KCl-induced contracture (IC50 1.52 +/- 0.1 mumol/l, n = 10) and this effect was counteracted by addition of CaCl2. Taken together the results indicate that the inhibitory effects of nonsteroidal antiestrogens on rat uterine contractions could be mediated by an action to block Ca2+ entry through an agonist action on extracellular estrogen receptors.     

瓜蒌提取物对离体家兔胸主动脉条收缩的影响

以兔离体主动脉条为实验材料,观察ＥＦＴ对去甲肾上腺素（ＮＥ）、氯化钾（ＫＣｌ）和氯化钙（ＣａＣｌ２）的剂量－效应曲线的影响及主动脉条的α受体及β受体的作用．观察了ＥＦＴ对ＮＥ引起的兔主动脉条２种收缩成分的影响．结果ＥＦＴ能舒张已被氯化钙、高钾和去甲肾上腺素收缩的兔主动脉条,使ＮＥ、ＫＣｌ、ＣａＣｌ２的剂量－效应曲线非平行右移,最大效应降低．ＥＦＴ松驰血管平滑肌的作用不依赖于阻断α受体或β受体．而与戊脉安（Ｖｅｒ）相似,是通过阻断钙通道实现的．但它们阻断钙通道的方式不同．ＥＦＴ可能无选择性阻断电位依赖性钙通道和受体操纵性钙通道,而Ｖｅｒ则只选择性阻断．因此,ＥＦＴ的扩血管机制与其对钙通道阻断作用有关     

Pimaradienoic acid inhibits vascular contraction and induces hypotension in normotensive rats

The present investigation was designed to investigate the effect of the diterpene ent-pimara-8(14),15-dien-19-oic acid (pimaradienoic acid, PA) on smooth muscle extracellular Ca(2+) influx. To this end, the effect of PA on phenylephrine- and KCl-induced increases in cytosolic calcium concentration ([Ca(2+)](c)), measured by the variation in the ratio of fluorescence intensities (R340/380 nm) of Fura-2, was analysed. Whether bolus injection of PA could induce hypotensive responses in conscious normotensive rats was also evaluated. PA inhibited the contraction induced by phenylephrine (0.03 or 10 micromol L(-1)) and KCl (30 or 90 mmol L(-1)) in endothelium-denuded rat aortic rings in a concentration dependent manner. Pre-treatment with PA (10, 100, 200 micromol L(-1)) attenuated the contraction induced by CaCl(2) (0.5 nmol L(-1) or 2.5 mmol L(-1)) in denuded rat aorta exposed to Ca(2+)-free medium containing phenylephrine (0.1 micro mol L(-1)) or KCl (30 mmol L(-1)). Interestingly, the inhibitory effect displayed by PA on CaCl(2)-induced contraction was more pronounced when KCl was used as the stimulant. Phenylephrine- and KCl-induced increases in [Ca(2+)](c) were inhibited by PA. Similarly, verapamil, a Ca(2+)-channel blocker, also inhibited the increase in [Ca(2+)](c) induced by either phenylephrine or KCl. Finally, bolus injection of PA (1-15 mg kg(-1)) produced a dose-dependent decrease in mean arterial pressure in conscious normotensive rats. The results provide the first direct evidence that PA reduces vascular contractility by reducing extracellular Ca(2+) influx through smooth muscle cellular membrane, a mechanism that could mediate the hypotensive response induced by this diterpene in normotensive rats.     

Effect of nitroglycerine in popliteal preparations from patients with peripheral occlusive arteriopathy precontracted with KCl or 5-hydroxytryptamine

1. At the present time, there are no studies in isolated arteries from patients suffering from peripheral occlusive arteriopathy (POA). In the present study, we attempt to characterize the effect of nitroglycerine (GTN) in isolated popliteal preparations obtained after leg amputation in 60-90-year-old men and women suffering from POA. 2. After surgical operation, arterial samples were stored in a refrigerator at 4 degrees C and, after 12-36 h, they were cut into rings and mounted in organ baths containing Krebs'-Henseleit solution at 37 degrees C and gassed constantly with 95% CO2 and 5% O2. Because noradrenaline elicited very poor contractile responses in these preparations, in the present study we evaluated the concentration-dependent contractions induced by KCl (15-90 mmol/L) and 5-hydroxytryptamine (5-HT; 10-7 to 10-4 mol/L) in arteriopathic popliteal rings and, when the corresponding maximum contractile effect had been obtained, we also evaluated the concentration-dependent relaxing effect produced by GTN (10-10 to 10-5 mol/L) in all precontracted preparations. As a reference, similar experiments were performed in popliteal preparations obtained following surgery on non-arteriopathic vascular tissue where it was necessary to resect a certain percentage of healthy vessel. 3. The responses to KCl and 5-HT were greater in healthy vessel than in arteriopathic rings. The relaxing effect of GTN was greater in preparations precontracted with 5-HT than in those preparations precontracted with KCl. In addition, preparations precontracted with KCl relaxed even less when they were obtained from patients with POA. 4. The present data indicate that GTN is a vasodilator with little effect on depolarized arteries. The results also indicate that the effect of this drug is even less in depolarized arteries from patients with POA.     

阿司匹林铜对离体兔主动脉血管条收缩的影响(英文)

目的:观察阿司匹林铜对离体免胸主动脉血管平滑肌的作用。方法:取免胸主动脉条,观察阿司匹林铜对去甲肾上腺素(NE)、KCl、CaCl_2诱导收缩作用的影响。结果:证实阿司匹林铜和对照物硫酸铜拮抗NE诱导的兔胸主动脉条收缩,IC_(50)分别为31nmol/L和0.29μmol/L,而阿司匹林本身没有拮抗作用。阿司匹林铜对KCl、CaCl_2诱导的收缩没有影响。在去内皮细胞兔胸主动脉条上,观察到相同的作用。结论:阿司匹林铜具有较强的拮抗NE诱导离体兔胸主动脉条收缩的作用,但不能拮抗KCl、CaCl_2诱导的收缩,提示阿司匹林铜通过阻断受体调控钙通道,舒张血管平滑肌。     

薤白提取物对兔离体主动脉条的作用

本实验以离体兔主动脉条为标本 ,对薤白 (EA)的扩血管机制进行了探讨 .观察了薤白对去甲肾上腺素 (NE)、氯化钾 (KCl)和氯化钙 (CaCl2 )的剂量 效应曲线的影响及主动脉条的α受体及 β受体的作用 .观察了EA对NE引起的兔主动脉条两种收缩成分的影响 .结果表明EA能舒张已为氯化钙、高钾和去甲肾上腺素收缩的兔主动脉条 ,使NE、KCl、CaCl2 的剂量 效应曲线非平行右移 ,最大效应降低 .EA松弛血管平滑肌的作用不依赖于阻断α受体或 β受体 ,而与戊脉安 (Ver)相似 ,是通过阻断钙通道实现的 .但它们阻断钙通道的方式不同 .EA可能无选择性阻断电位依赖性钙通道和受体操纵性钙通道 .因此EA的扩血管机制与其对钙通道阻断作用有关 .     

Effects of l-tetrahydropalmatine on isolated rabbit arterial strips

The effects of l-tetrahydropalmatine (THP) on isolated rabbit aortic, renal and superior mesenteric arterial strips were studied in comparison with verapamil (Ver). THP and Ver shifted the KCl, CaCl2, norepinephrine (NE) and 15-methyl prostaglandin F2 alpha dose-response curves to the right in a non-parallel fashion, and decreased the maximal response, showing noncompetitive antagonism. THP was less potent in dilating arterial strips than Ver. THP and Ver obviously inhibited the intracellular Ca2+-dependent component of NE-induced contraction of the aorta, but only slightly decreased the extracellular Ca2+-dependent component when the concentration of THP or Ver was very high (THP 0.1 mmol/L, Ver 10 mumol/L). The results suggest that THP, similar to Ver, mainly inhibits potential-operated calcium channels. THP and Ver were more potent in dilating renal and superior mesenteric arterial strips than aortic strips. The results indicate that the vasodilation effect of THP is similar to that of Ver and that THP probably has a calcium antagonistic effect.