Calcium mediation of the pig jejunal secretory response

The involvement of Ca++ ions as secretory mediators in pig jejunal epithelia has been investigated with an in vitro system. Omission of Ca++ from the Ringer-HCO3 bathing media on both sides of the tissue had minor effects on the basal electrical activity of pig jejunal mucosa. There were only slight decreases in transepithelial potential difference and increases in conductance with Ca++ free media. Low EGTA concentrations which reversibly blocked potential difference responses to secretory agents also had minimal effects on basal electrical activity. The in vitro secretory responses to A23187, to theophylline, and to Escherichia coli heat-stable enterotoxin were all eliminated by Ca++ depletion and restored by replacing normal Ca++ concentrations in the bathing media. Dantrolene prevented the secretory response but not the potential difference increases caused by heat-stable enterotoxin and A23187, suggesting that intracellular Ca++ stores may be reservoirs of secretory signal agent. Verapamil only blocked the secretory response to heat-stable enterotoxin. Chlorpromazine had negligible effects on basal conditions, but totally blocked both the secretory response and the Ca++-dependent effects of A23187 and heat-stable enterotoxin on potential difference. The response to theophylline was only partially inhibited by chlorpromazine, implying some involvement of both cAMP and Ca++ as secretory signals for theophylline. Cytoplasmic Ca++ concentrations appear to be at least as important as cyclic nucleotides in regulating the secretory effects of pig jejunum.     

中药青龙衣镇痛机制研究──青龙衣无机盐及其模拟成分对小鼠脑内钾、钙离子含量的影响

本文观察了青龙衣无机盐及其模拟成分对小鼠脑内钾、钙离子的影响。结果表明，Ｋ＋／Ｃａ＋＋比值与痛阈之间存在着相关性。青龙衣无机盐及模拟成分硫酸钾均有较强的镇痛效果；均能增加小鼠脑内钾离子含量，同时降低钙离子含量，Ｋ＋／Ｃａ＋＋比值明显增高；其镇痛作用均因注射氯化钙而被拮抗。研究表明，青龙衣无机盐是镇痛的有效成分。     

家兔化学裸露心肌标本制备及其张力-pCa关系

家兔右室乳头肌在含3mM EDTA、5mM Na_2ATP、10mM Tris、140 mM KCl的溶液中浸浴150min,其Ca~(2+)通透性显著增高。Ca~(2+)浓度为10~(-7)M时,便可产生张力,10~(-4.6)M时,张力达到最大。相对张力-pCa(Ca~(2+)浓度的负对数)关系近似一S形曲线,产生50％最大张力的Ca~(2+)(pCa_(50))约为10~(-6.6)M。同法制备的大鼠乳头肌Ca~(2+)通透性未见增高。     

血小板激活因子对大鼠肾小球系膜细胞作用研究

目的探讨血小板激活因子(PAF)对大鼠肾小球系膜细胞(GMC)的影响及其机制。方法利用体外培养的大鼠MGC与PAF作用,并以各类拮抗剂观察其对GMC的影响。结果 PAF刺激后GMC死亡率与对照组相比较有显著性差异,细胞内蛋白(Pr)漏出增加,细胞外钙内流增加及脂质过氧化加强(P<0.01)。verapamil组与PAF组相比较。GMC死亡率有所减少。细胞外钙内流显著减少。银杏叶组与PAF组相比较,GMC死亡率、细胞脂质过氧化、细胞内Pr漏出及细胞外钙内流均显著减少。MnSo_4组与PAF组相比较,钙内流有所减少,但无显著性差异(P>0.05)。结论 PAF作用于GMC机制与其通过受体影响细胞膜钙通道开放,促进脂质过氧化,从而损伤GMC有关,而与Na~+/Ca~(++)交无关。     

Nimodipine reduces morbidity, mortality after disruption of cerebral blood flow

Nimodipine is a 1,4 dihydropyridine with Ca++ channel blocking properties. It is more lipophilic than most calcium channel blockers, and thus has a greater volume of distribution within the brain. Many actions of nimodipine have been proposed from work done in animal models following induction of complete or partial cerebral ischemia for varying lengths of time. However, these experimental results have not been sufficiently documented in patient populations, and there exists conflicting data as to nimodipine's mechanism of action in the cerebral ischemic patient. Regardless of the exact mechanisms of action, studies suggest that nimodipine may significantly reduce morbidity and mortality in patients following disruption of cerebral blood flow.     

Effects of substance P on spontaneous contraction in the flexure region of the guinea pig colon

Effects of Substance P on spontaneous contractions of the circular muscle of the flexure region of guinea pig colon were studied by mechanical tension recording. Substance P (3 nM-10 nM) produced tonic contraction associated with phasic activities but the contraction was found stronger at higher concentration. Verapamil (3 microM), a voltage dependent L-type Ca(2+) channel blocker completely blocked the spontaneous activities and also Substance P induced contraction. These results suggest that Substance P produce contraction by Ca(2+) influx and the Ca(2+) influx occurs by activating verapamil sensitive Ca(2+) channel.     

黄连素对灌流心脏发生心衰的保护作用

目的　探讨黄连素对心脏衰竭的发生有无保护作用。方法　采用 L angendorff法灌流离体心脏 ,用维那帕米造成急性心衰 ;比较用黄连素和不用黄连素的心脏心衰程度的差异。结果　用黄连素 (10 - 6 mol/ L)灌流心脏后再用维那帕米致衰 ,此时心衰发生的程度明显轻于未用黄连素组 (P<0 .0 0 1)。结论　黄连素对心力衰竭的发生具有保护作用     

黄连素对灌流心脏发生心衰的保护作用

目的 探讨黄连素对心脏衰竭的发生有无保护作用。方法 采用Langendorff法灌流离体心脏,用维那帕米造成急性心衰;比较用黄连素和不用黄连素的心脏心衰程度的差异。结果 用黄连素（10^-6mol/L）灌流心脏后再用维那帕米致衰,此时心衰发生的程度明显轻于用未用黄连素组（P＜0．001）。结论 黄连素对心力衰竭的发生具有保护作用。     

枳实对小肠收缩中钙作用的影响

枳实对乙酰胆碱（Ａｃｈ）及高Ｋ＋去极化后Ｃａ２＋所引起的小鼠离体小肠收缩均有比较明显的抑制作用，其作用均可通过增加浴液中的Ｃａ２－浓度而被对抗。累积量效曲线表明：枳实与ＣａＣｌ２呈非竞争性拮抗，两种浓度的枳实对Ａｃｈ所致的依细胞外Ｃａ２２＋的收缩反应有较强抑制作用，而对依细胞内Ｃａ２＋的收缩反应无明显抑制作用。枳实与维拉帕米相似，为Ｃａ２＋拮抗剂。     

钙离子对神经异常电活动的影响

外源性Ca~(2+)及Ca~(2+)通道阻断剂异搏定(verapamil)和硝酸镧(La(NO_?)_?)作用于神经脱髓鞘膜区,均可影响异常的神经冲动。5mmol/L Ca~(2+)不能使受损神经异常放电频率改变,10～20mmol/L Ca~(2+)总能引起兴奋效应,40mmol/L Ca~(2+)则可使异常电活动频率降低。静脉或局部应用异搏定不但可抑制受损神经自发性异常电活动,还可阻断四乙胺(TEA)诱发的电活动。La~(?)也可降低受损神经异常放电频率。而Ca~(2+)、异搏定及La~(?)作用于正常神经干,并不影响其正常传导与电活动。提示神经损伤区轴突膜上形成了Ca~(2+)通道,而来自损伤区的异常电活动与Ca~(2+)通道密切相关。     

钙ATP酶在豚鼠过敏性哮喘发病过程中的作用

本实验给致敏豚鼠吸入卵蛋白建立速发型过敏性哮喘的动物模型，观察了呼吸系总阻抗（Ｚｒｓ）及豚鼠肺组织钙ＡＴＰ酶（Ｃａ２＋－ＡＴＰａｓｅ）活性的变化以及６５４－２，异搏定对二者的影响。结果表明哮喘组Ｚｒｓ明显高于正常组（Ｐ＜０．０１），肺组织Ｃａ２＋－ＡＴＰａｓｅ活性明显低于正常组（Ｐ＜０．０１），６５４－２有增Ｃａ２＋－ＡＴＰａｓｅ活性的作用。说明在过敏性哮喘的发病过程中Ｃａ２＋－ＡＴＰａｓｅ活性下降是其病理生理变化的一个重要因素，细胞内钙浓度升高可能与此有关。     

东莨菪碱与维拉帕米对海洛因依赖大鼠戒断症状的影响

目的: 观察东莨菪碱和维拉帕米对海洛因依赖大鼠戒断症状的影响.方法: 采用逐日递增法建立海洛因依赖大鼠模型,用不同剂量的东莨菪碱合并维拉帕米处理动物后,腹腔注射纳洛酮5 mg/kg诱发戒断反应,记录戒断症状.结果: 单独皮下注射东莨菪碱或皮下注射维拉帕米可明显抑制海洛因依赖大鼠戒断症状,东莨菪碱(0.5 mg/kg,1 mg/kg)合并维拉帕米(10 mg/kg,20 mg/kg)使用时效果更好.结论: 东莨菪碱可能通过影响乙酰胆碱来减轻海洛因戒断反应;维拉帕米可能通过调节神经细胞钙离子的流入进而与东莨菪碱起协同作用.     

Renal calculi in primary hyperaldosteronism.

Increased urinary calcium (Ca++) excretion and the presence of negative Ca++ balance is well documented in primary hyperaldosteronism. However, renal calculi as a major manifestation of this disorder has not previously been described. This report describes a patient who presented with renal calculi in association with primary hyperaldosteronism. We believe that primary hyperaldosteronism was a major pathogenetic factor in the formation of renal calculi since the increased urinary excretion of Ca++ and uric acid noted at onset declined following a short-term spironolactone administration and remission from renal calculi has persisted following initial nephrolithotomy and continued spironolactone therapy, which also corrected hypertension and hypokalemia, a hallmark of this disorder.     

脉胳宁注射液扩血管作用机制的研究

用离体兔胸主动脉为标本，以维拉帕米(Ver)为时照药，观察了脉胳宁注射液时血管平滑肌的作用。结果，脉胳宁注射液时NEKCL及C2CL2收缩兔胸注动脉条的量效曲线呈非竞争性拮抗作用，并能明显抑制NE引起的主动脉备依赖于细胞外钙的收缩，其作用性质与ver相似。提示脉胳宁注射液的扩血管作用机制可能与其对钙通道的阻滞作用有关。     

The QT interval and serum ionized calcium

The correlation between serum ionized calcium (Ca++) levels and three ECG QT intervals (Q-OTC, Q-ATC, and Q-ETC) was assessed in 20 adult patients. The relationship between each QT interval and Ca++ level, based on 209 Ca++ determinations through a range of 1.0 to 4.0 mEq/liter, is best described by a hyperbolic function. Although Q-OTC and Q-ATC predict Ca++ levels more accurately than Q-ETC, all QT intervals are clinically unreliable as guides to the presence of hypercalcemia. Similarly, the usefulness of the QT intervals in the diagnosis of hypocalcemia is limited by the wide distribution of normal values.     

孕酮对兔窦房结细胞电活动的影响

目的：通过观察孕酮（P）对离体家兔窦房结细胞动作电位的影响，来探讨孕酮对窦房结细胞电活动的影响及其作用机制。方法：采用微电极技术，引导窦房结细胞动作电位，观察不同浓度孕酮对窦房结细胞动作电位各参数的影响。结果：（1）孕酮使兔窦房结细胞动作电位时程（APD20、APD50、APD90、APD）、总复极时间（RPT）显著延长。孕酮对窦房结细胞动作电位各参数的影响呈时间、浓度依赖性。（2）孕酮使兔窦房结细胞动作电位幅度（APA）减小，零期最大降极速率（Vmax)减慢，使窦房结细胞0期除极时间（DPT）延长。结论：较高浓度的孕酮对离体家兔窦房结细胞的K^ 通道有一定程度的阻断作用，对其Ca^2 通道可能也有阻断作用。     

[D-Pen~2,D-Pen~5]enkephalin在NG108-15细胞株对Bt_2cAMP和佛波醇酯促进的钙内流的影响

在NG108-15细胞株上,用荧光探针fura-2/AM测定细胞内游离钙([Ca~(2 )]1)浓度。结果表明:丁二酰cAMP(Bt_2cAMP)、腺苷酸环化酶激动剂forskolin和蛋白激酶C激动剂十四碳酰佛波醇酯(TPA)均能使([Ca~(2 )]i)升高。钙通道拮抗剂异搏定(verapamil)可以抑制forskolin、Bt_2cAMP和TPA引起的[Ca~(2 )]i增加。δ阿片受体激动剂[D-Pen~2,D-Pen~5)enkephalin(DPDPE)能抑制Bt_2cAMP和forskolin引起的[Ca~(2 )]i增加,但不影响TPA引起的[Ca~(2 )]i增加。提示DPDPE可抑制cAMP依赖的蛋白激酶引起的钙内流,而与蛋白激酶C(PKC)引起的钙内流无关。     

Hemolysins of Edwardsiella tarda.

Isolates of Edwardsiella tarda from four sources produced nonfilterable hemolsin in trypticase soy broth. The cell-associated hemolysin was partially heat labile, destroyed by formalin and sensitive to treatment with trypsin. These characteristics, and the observation that Ca++ or Mg++ ions enhanced activity, suggest that a proteinaceous, enzymic component may be responsible for the hemolytic activity.     

莲心碱抗实验性心律失常作用的研究

莲心碱5mg/kg,ⅳ可显著地对抗乌头碱诱发的大鼠及哇巴因诱发的豚鼠心律失常;也能预防肾上腺素所致的豚鼠室颤发生;还能对抗心肌缺血复灌所致的大鼠心律失常。莲心碱8mg/kg,ⅳ能使家兔心率减慢,P-R间期延长;莲心碱30μmol/L可延长离体豚鼠左房功能性不应期。结果提示,莲心碱抗实验性心律失常作用可能主要与其阻滞Ca++内流有关。     

Effects of L-THP on Ca2+ Overload of Cultured Rat Cardiomyocytes during Hypoxia and Reoxygenation

Ca2 overloadisoneoftheimportantpathophys-iologicalcharactersofcardiomyocyteinjuryfOllowinghypoxia--reoxygenation.TrlggeredactivitycausedbyCa2 overloadisthemaincauseofreperfusion--arryth-mias[l].L--tetrahydropalmatine(L--THP),alsonamedrotundium,isabiologica1alkaliofcorydalisYanhusuo,aherbalCa' antagonistwhichhasbeenwidelyusedintreatingarrythmias['].Herewedevel-opedacellmodelofhypoxiaandreoxygenationwithculturedratcardiomyocytes,whichwassimilartothemodelofischemia--reperfusioninjuryoftheheart…