腺苷对心肌梗死再灌注无复流的保护作用及其对一氧化氮和内皮素影响的实验研究

目的:探讨腺苷对心肌梗死再灌注无复流的保护作用,以及这种保护作用与腺苷对一氧化氮(NO)和内皮素(ET)影响的关系。方法:制作离体兔心急性心肌梗死模型。30只兔心随机分为三组:A:假手术组,B:心肌梗死再灌注组,C:腺苷+心肌梗死再灌注组。分别取灌流开始5min和再灌流90min时冠脉流出液2ml,测定乳酸脱氢酶(LDH)、肌酸激酶(CK)、内皮素(ET)及一氧化氮(NO)含量。灌流结束时,测量无复流区域面积的百分比,并在光镜下观察心肌细胞的变化情况。结果:(1)A组灌流开始与结束时和B组、C组开始灌流时冠脉流出液中LDH、CK含量相比无显著性差异;(2)B组各项化验指标分别进行组内比较其结果有统计学差异。(3)灌流结束时,B组与C组相比NO的降低和ET的升高有统计学差异。(4)C组和B组比较无复流区域面积百分比明显缩小,有统计学差异。结论:腺苷对心肌梗死再灌注无复流具有明显的保护作用。腺苷升高NO和降低ET的作用可能是其发挥保护作用的原因之一。     

冠心康对实验性家兔动脉粥样硬化血清NO及血浆ET-1的影响

目的 :观察中药冠心康预防用药对食饵性动脉粥样硬化 (AS)家兔血清一氧化氮 (NO)及血浆内皮素 1(ET 1)的影响。方法 :采用猪油加胆固醇饲料造模法 ,建立家兔动脉粥样硬化模型。随机分为正常对照组 (N组 ) ,模型组 (M组 ) ,冠心康治疗组 (T组 ) ,复方丹参片治疗对照组 (C组 ) ,各组在实验开始 ,第 6周末 ,第 12周末取血标本测定上述参数。结果 :与M组比较 ,T组、C组均可显著提高血清NO含量 ,降低血浆ET 1含量 (P <0 .0 5 ) ,且T组与C组比较有显著差异(P <0 .0 5 )。结论 :冠心康有维持内源性ET 1和NO的平衡而保护正常内皮功能的作用 ,这可能是其防治冠状动脉粥样硬化和抗心肌缺血作用的机制之一     

A small-conductance charybdotoxin-sensitive,apamin-resistant Ca2+-activated K+ channel in aortic smooth muscle cells (A7r5 line and primary culture)

A small conductance K⁺ channel was identified in smooth muscle cells of the rat aortic cell line A7r5 and also in rat aortic smooth muscle cells in primary culture, using conventional single-channel recording techniques. The single-channel conductance shows no rectification, either in the range –70 to +40 mV under asymmetrical conditions (9.1 pS), or in the range –100 to +50 mV in symmetrical 150 mM K⁺ (37 pS). Channel activity is reversibly inhibited by extracellular application of charybdotoxin, with a concentration of 8 nM producing half-maximal inhibition. It is unaffected by apamin or scyllatoxin. Channel activity depends on the presence of free Ca²⁺ on the cytosolic face of the membrane, with an activation zone between 0.1 and 1 M. This small-conductance, charybdotoxin-sensitive, Ca²⁺-regulated K⁺ channel is activated by vasoconstrictors such as vasopressin and endothelin.     

充血性心力衰竭治疗前后内皮素，肿瘤坏死因子和血管紧张素转化酶含量比较

目的探讨充血性心力衰竭(CHF)患儿不同心功能级数及分组治疗前后血浆ET、TNF和ACE含量的变化及其意义。方法用放免法和比色法分组测定充血性心力衰竭(CHF)80例患儿血中ET、TNF和ACE含量的变化。结果80例CHF患儿中血中ET、TNF和ACE含量分别为(141.33±8.56)ng/L、(168.25±35.14)ng/L和(429.45±61.33)IU,与正常对照组比较均明显升高(P＜0.05);心功能Ⅱ级与心功能Ⅲ级、心功能Ⅳ级TNF、ET含量间比较均有显著性差异(P＜0.05～0.01),相关有显著性意义;不同心功能级数CHF患儿血浆TNF、ET和ACE含量治疗后较治疗前明显降低,均有显著性差异(P＜0.05～0.01),而且心功能越差,血浆TNF、ET水平恢复越慢,洛汀新组心功能改善较常规组明显,两者含量间比较有显著性差异(P＜0.05)。结论血浆ET、TNP和ACE含量的测定有助于判断心力衰竭的程度,洛汀新组的疗效明显优于常规组。     

乌拉地尔对重症高血压患者血浆降钙素基因相关肽、内皮素、神经肽Y含量的影响

目的：观察乌拉地尔(Ura)对重症高血压（CH)患者血浆降钙素基因相关肽（CGRP）、内皮素（ET）、神经肽Y（NPY）含量的影响。方法：用放射免疫分析方法测定30例CH患者血浆CGRP、ET、NPY水平,并以40例健康者作对照。观察CH患者静脉注射Ura(0.4-0.6mg/kg)后诸指标变化。结果：CH患者血浆CGRP水平显著低于健康对照组（P＜0．01）,ET和NPY明显高于健康对照组（均P＜0．01）。经Ura治疗后CH患者CGRP水平明显升高,ET、NPY水平明显下降（均P＜0．01）。结论：CGRP,ET和NPY是参与CH发病的重要体液因素,Ura可明显提高CH患者体内CGRP水平,有效拮抗ET和NPY的缩血管作用,对改善CH患者血流动力学和心肌氧供需失平衡有重要作用。     

游泳训练大鼠血浆生物活性肽含量的变化及意义

目的研究运动性心肌肥大形成中血浆生物活性肽的含量及意义.方法wistar大鼠分为运动训练组和对照组,NPY、CGRP、ET和ANP用放射免疫方法测定,血压和心率用八道生理记录仪记录.结果(1)运动组大鼠游泳训练8周后,心脏系数比对照组增加36.8%(P＜0.05),而收缩压、舒张压、平均动脉压和心率与对照组无差异(P＞0.05);(2)运动组心肌肥大大鼠血浆NPY均比照组降低88%(P＜0.01);(3)运动组心肌肥大大鼠血浆CGRP比对照组升高31%(P＜0.01);(4)运动组血浆ET和ANP浓度与对照组无差异.结论运动性心肌肥大形成中血浆的CGRP、NPY含量变化不同,提示CGRP和NPY对运动性心肌肥大的形成可能有重要作用.     

化湿汤对冠心病患者血浆心钠素、内皮素及 血脂的影响及临床观察

应用化湿汤治疗50例痰浊型冠心病（CHD）患,并与冠心Ⅱ号方治疗血瘀型冠心病患50例作对照。结果表明：两组皆取得较好的疗效。用药后不仅心绞痛等症状明显缓解,而且能改善心电图,降低血浆心钠素（ANP）,内皮素（ET）和血脂（TC、TG）等临床客观指标。其作用机制可能与阻滞细胞Ca^ 内流有关。     

Comparison of the positive inotropic effects of serotonin,histamine, angiotensin II,endothelin and isoprenaline in the isolated human right atrium

Summary The receptor systems through which serotonin (5-HT), histamine, angiotensin II and endothelin increase the force of contraction were studied in isolated right atria from patients without apparent heart failure.All agonists increased the atrial force of contraction in a concentration-dependent manner; maximal effects, however, were significantly less than those evoked by isoprenaline or Ca²⁺. 5-HT and histamine, but not angiotensin II and endothelin, activated adenylate cyclase, whereas endothelin and angiotensin II stimulated inositol phosphate generation. Experiments with subtype-selective antagonists revealed that histamine effects were mediated by H₂-receptors (sensitive to ranitidine), 5-HT-effects by 5-HT₄-receptors (sensitive to SDZ 205-557) and angiotensin II effects by AT₁-receptors (sensitive to losartan).We conclude that in human right atria the force of contraction can be increased by cyclic AMP-dependent (histamine, 5-HT) and -independent (angiotensin II, endothelin) pathways. Compared to -adrenoceptors, however, all other receptor systems increase the force of contraction only submaximally indicating that the -adrenoceptor pathway is the most important physiological mechanism to regulate force of contraction and/or heart rate in the human heart.Correspondence to O. E. Brodde at the above address     

Endothelin-1 induced contraction of rat aorta: contributions made by Ca2+ influx and activation of contractile apparatus associated with no change in cytoplasmic Ca2+ level

Summary The modes by which Endothelin-1 (ET) induces Ca²⁺-influx and the relative functional importance of the different sources of Ca²⁺ for ET-induced contraction were studied using fura 2-loaded and unloaded rat aortic strips. ET caused an increase in the cytosolic free Ca²⁺ level ([Ca²⁺]_i) followed by a tonic contraction in Ca²⁺-containing solution, and produced a transient elevation of [Ca²⁺]_i followed by a small sustained contraction in Ca²⁺-free medium. ET also stimulated ⁴⁵Ca influx into La²⁺-inaccessible fraction significantly. With the same change of [Ca²⁺]_i, ET caused a larger tension than that induced by high K. ET-induced contraction and [Ca²⁺]_i elevation were not significantly inhibited by 0.1–0.3 M nicardipine which nearly abolished the contraction and [Ca⁺]_i elevation produced by high K. During treatment of the strips with high K, addition of ET induced further increases in [Ca²⁺]_i and muscle tension, and vice versa. In Ca²⁺-free medium, ET-induced contraction was influenced neither by ryanodine-treatment nor by high K-treatment, although the former attenuated and the latter potentiated the [Ca²⁺]_i transient induced by ET. Further, the ET-induced sustained contraction under Ca²⁺-free conditions began to develop after the [Ca²⁺]_i level returned to the baseline. Thus, it seems that the Ca²⁺ released from the ryanodine-sensitive and -insensitive Ca²⁺ stores by ET may provide only a minor or indirect contribution, if any, to the tension development. ET might cause a contraction mainly by stimulating Ca²⁺-influx through Ca²⁺ channel(s) other than voltage-dependent Ca²⁺ channels in character, and by increasing the sensitivity of the contractile filaments to Ca²⁺ or activating them Ca²⁺-independently.Visiting from Zun Yi Medical College, China Send offprint requests to I. Takayanagi at the above address     

川芎嗪对肾小球疾病患者血浆内皮素和降钙素基因相关肽的影响

目的：通过研究川芎嗪（tetramethyl pyrazine,TMP）对肾泪示疾病血浆内皮素（endothelin-1,ET-1）和降钙素基因相关肽（calcitonin gene related peptide,CGRP)的影响,探讨川芎嗪改善肾脏血液循环,保护肾功能的机理。方法：对肾小球疾病病例在同等治疗基础上,治疗组加用川芎嗪,对照组不用川芎嗪,分别检测两组病人治疗前和治疗后血浆中ET－1和CGRP含量。结果：治疗组治疗后与治疗前比较血浆中的ET－1下降和CGRP上升,均有特别显著性差异;对照组治疗前后比较,血浆中ET－1下降和CGRP上升,显著性差异。结论：川芎嗪治疗肾小球疾病可能是通过减少内皮细胞ET－1的产生和促进CGRP的生成,改善肾脏血液循环,对肾功能起保护作用。