心喘灵(XC-1)及其衍生物XC-2对肾上腺素受体及动脉平滑肌的作用

本文用放射配基结合法研究了心喘灵(XC-1)及其衍生物XC-2对肾上腺素受体的亲和力,用离体器官方法观察了二者对α受体功能的影响,用酶分析法研究了两药对β受体功能的影响。两药各种作用强度相近,对大鼠脑皮层细胞膜α受体有中等强度亲和力(Ki10^-6mol/L),对兔主动脉和大鼠肛尾肌α₁受体均有中等强度阻断作用,但对大鼠输精管突触前α₂受体只有微弱的阻断作用。二药抑制由ISO激动的腺苷酸环化酶活性的IC₅₀均为3.6×10^-5mol/L。此外,二者都能拮抗CaCl₂,KCl和5-HT引起的主动脉条收缩反应并有直接扩张血管的作用。     

川芎嗪对犬心脏血流动力学的作用

给麻醉犬静脉滴注川芎嗪1、2及4 mg/kg/min,连续10分钟;动物出现心率加快,心肌收缩力加强,血管扩张。这些作用随剂量的增加而加强。滴注1 mg/kg/min时,心率、LVP及dp/dt max增加,2 mg/kg/min时,心率、LVP、dp/dt max及冠脉血流明显增加。剂量增至4 mg/kg/min时,除上述指标明显增加外,还出现LVEDP、CI,心肌氧耗和脑血流增加,冠状动脉和脑血管阻力及总外周阻力降低。给清醒高血压犬滴注川芎嗪4 mg/kg/min及一次静注20'mg/kg也引起心率加速。心得安(ⅳ1～2 mg/kg)能对抗川芎嗪对麻醉和清醒犬的上述作用,而利血平则不能完全对抗川芎嗪的作用。     

心喘灵对心脏保护作用的实验观察

心喘灵(XC-1)ip 26 mg/kg可使小鼠利多卡因中毒时的死亡率由对照组的14/20下降至2/20(p<0.05);iv时,其拮抗利多卡因毒性的ED_(50)为18.1±0.3mg/kg。iv XC-1 5～10mg/kg并可分别拮抗BaCl_2和CaCl_2诱发的大鼠心律失常;ip2.5mg/kg亦能明显降低氯仿诱发的小鼠室颤率(p<0.01)。在整体和离体实验中发现,XC-1可明显减慢心率,且能拮抗异丙肾上腺素加快心率的作用。实验结果提示,XC-1可能是通过阻滞β受体,降低心肌耗氧而对心脏产生一定的保护作用.     

重组人脑钠肽对慢性心衰犬血流动力学和肾功能的影响

目的研究国产重组人脑钠肽(rhBNP)对慢性心衰犬血流动力学及肾功能的影响。方法用右心室快速起搏(RVP)或狭窄下腔静脉(TIVCC)形成犬的心衰模型。结果RVP心衰犬iv rhBNP后,平均动脉压(MAP)、左室内压(LVSP)、LVdp/dt、肺动脉压(PAP)、左室舒张末期压(LVEDP)、总外周阻力(TPR)及肾血管阻力(RVR)呈剂量依赖性下降,LVdp/dt/P、左室做功(LVW)、心输出量(CO)和心率(HR)无明显改变;TIVCC心衰犬在iv同剂量rhBNP后,MAP,LVEDP和CO下降,其他心功能指标无明显改变。两种心衰犬给药后尿量和尿钠排出量均增加。结论rhBNP有舒张血管和利尿作用,能明显降低心衰犬的心脏前后负荷,不影响心脏收缩功能。     

中国萝芙木碱Verticillatine对麻醉狗和猫心功能与血流动力学的影响

Verticillatine(Vt)0.5～1.0mg/kg iv,能使麻醉狗的血压下降,心率减慢,cl,LVSP LV dp/dt max,LVWI,TPR降低,作用随剂量增加而加强。冠脉阻力稍降低,但心肌氧利用率和氧耗减少。颈内动脉和股动脉血流增加,阻力减少。给麻醉猫iv Vt和六羟季铵1.0 mg/kg后,BP,LVP和LV dp/dt max降低,但LV dp/dt/p和LVEDP无明显变化。说明Vt能降低心脏后负荷,对前负荷无明显影响。     

中国萝芙木碱Verticillatine对麻醉狗和猫心功能与血流动力学的影响

Verticillatine(Vt)0.5～1.0mg/kg iv,能使麻醉狗的血压下降,心率减慢,cl,LVSP LV dp/dt max,LVWI,TPR降低,作用随剂量增加而加强。冠脉阻力稍降低,但心肌氧利用率和氧耗减少。颈内动脉和股动脉血流增加,阻力减少。给麻醉猫iv Vt和六羟季铵1.0 mg/kg后,BP,LVP和LV dp/dt max降低,但LV dp/dt/p和LVEDP无明显变化。说明Vt能降低心脏后负荷,对前负荷无明显影响。     

重组人脑钠肽及米力农对麻醉犬血流动力学及肾功能的影响

目的观察重组人脑钠肽(rhBNP)对麻醉犬血流动力学和肾功能的作用。方法给麻醉开胸犬恒速输注rhBNP(采用累积给药方式),或iv米力农后,进行血流动力学测定,并测定尿量、尿钠和血钠含量。结果rhBNP可使MAP,LVSP,LVdP/d_t,PAP,LVEDP,TPR及RVR呈剂量依赖性下降,CO有增加趋势,尿量和尿钠排出量呈剂量依赖性增加。米力农则明显降低MAP,PAP,LVEDP,TPR,RBF及RVR,升高LVSP,LVdP/d_t和CO,加快心率,对尿量、尿钠排出量和血钠无明显影响。结论rhBNP能明显降低心脏前后负荷,改善心脏功能;可舒张肾动脉,有扩张血管和利尿排钠作用。米力农则有正性肌力和频率作用,无利尿利钠作用。     

绞股蓝皂甙和人参皂甙对犬心脏血流动力学作用的比较

麻醉开胸犬,左心室和股动脉插管用压力换能器测左心室内压和血压;电磁流量计测心输出量、冠状窦和颈内动脉血流量;多道生理记录仪记录各项指标.iv绞股蓝皂甙5或10 mg/kg和人参皂甙10mg/kg能明显降低犬血压和总外周阻力、脑血管与冠状血管阻力,增加冠脉流量,减慢心率,使心脏张力-时间指数下降,对心肌收缩性能和心脏泵血功能无明显影响.与等剂量人参皂甙比较,绞股蓝皂甙的作用略强.     

肉毒碱对实验性衰竭心脏功能的影响

肉毒碱carnitine是一广泛存在于组织中的氨基酸,本文报告人工合成d,l-carnitine盐酸盐(VBt)对麻醉猫衰竭心脏及离体豚鼠衰竭心脏功能的影响。用缓慢恒速静注戊巴比妥钠引起猫急性心衰。给心衰猫静注VBt 50 mg/kg/min,共5分钟。给药后,MAP、LVP及LVdp/dt max均明显升高,CVP及LVEDP轻度下降,HR无明显改变。当VBt与毒毛旋花子甙K合用时,能增加后者引起心律失常的剂量和治疗宽度。VBt对正常离体豚鼠心脏除引起HR减慢外,对心收缩力和冠脉血流量均无明显影响。当用乏氧灌流引起急性心衰时,VBt则加强心收缩力和增加冠脉血流,并推迟心衰的发展。此外VBt还能使大鼠心肌组织耗氧量明显降低。     

心力衰竭时静注氨力农的血流动力学与血药浓度的关系

对8例心力衰竭患者静注国产氨力农1mg/kg,继以7.5μg/(kg·min)静滴6h。由漂浮导管测定血流动力学变化,HPLC法测血药浓度的改变。结果:心指数在血药浓度为1.05μg/mL左右时增加较大(最大增幅为23.8％),但不随浓度的继续上升而增高,两者有一定相关性(r=0.72,P<0.05)。肺动脉压和肺楔嵌压显著下降,但与血药浓度变化无关。提示该药的扩血管作用较明显,但可能存在耐受性。     

三七根、叶、花皂甙对麻醉犬血流动力学的影响

本文研究了三七根、叶、花总甙及三七皂甙C₁和E₁对麻醉犬血流动力学的作用。结果表明:根总甙明显降低动脉血压和总外周阻力,增加心输出量和减慢心率,降低心肌耗氧指数。根总甙中含量最多的单体皂甙C₁(即人参皂甙Rg₁)可使血压短时下降,但LV dp/dt_max和心输出量显著增加,伴总外周阻力明显下降。叶总甙及其含量较多的皂甙E₁(即人参皂甙Rb₁)对上述指标均无明显影响。花总甙的作用温和短暂。这些结果提示三七根皂甙是心血管药理作用的活性成分,地上部分皂甙无明显心血管作用,且毒性较大。     

Effects of a 2-substituted adenosine derivative, 2-(p-methoxyphenyl)-adenosine (CV-1674) on coronary and cardiohemodynamics, and myocardial energetics

In dogs, intracoronary doses of CV-1674, adenosine ( ADS) and 2-Cl-ADS for doubling coronary flow were estimated as 5.0, 2.0 and 0.4 microgram/dog, and i.v. doses 31, 71 and 2.5 microgram/kg, respectively. ADS and 2-Cl-ADS decreased, while CV-1674 increased LV dp/dt. Intravenous infusion (30 min) of CV-1674 (10 microgram/kg per min) and ADS (700 microgram/kg per min) decreased coronary resistance to approximately the same extent. Decreases in blood pressure, total peripheral resistance and myocardial O2 concumption with ADS were more prominent than those with CV-1674. ADS produced a marked bradycardia that was not evident with CV-1674. Neither agent had a significant influence on myocardial efficiency. In guinea pig atria, ADS and 2-Cl-ADS exerted negative effects while those with CV-1674 were positive inotropic and chronotropic. In cats, intraduodenal ADS (10 mg/kg) produced no effects on cardiohemodynamic parameters. CV-1674 (250 and 500 microgram/kg) increased myocardial tissue blood flow (MBF) with a slight hypotension in a dose-dependent manner, whereas 2-Cl-ADS (100, 250 and 500 microgram/kg) increased MBF only with the highest dose concomitantly with marked hypotension and bradycardia. These results suggest that CV-1674 induces selective coronary vasodilation with less depression on cardiohemodynamics, and is relatively well absorbed from the intestinal tract. The pharmacological profile of the compound, therefore, differs from that of ADS and 2-Cl-ADS.     

Ouabain pretreatment does not compromise the hemodynamic and myocardial energetic effects of CK-3197, a selective positive inotropic agent,in dogs with propranolol-induced heart failure

We examined the interaction between ouabain and CK-3197, a new selective positive inotrope, on the hemodynamic and myocardial energetic parameters of anesthetized dogs with propranolol-induced heart failure (PIHF). Mongrel dogs (13–18kg) of either sex were anesthetized with pentobarbital sodium (35mg/kg, i.v.) and instrumented for routine hemodynamic measurements using an open-chest, artificially ventilated preparation. PIHF was produced by decreasing left ventricular (LV) dp/dt max by 50% from control values with an intial infusion of 0.5 mg/kg of propranolol followed by continuous infusion of 0.02 to 0.08 mg/kg of propranolol to maintain PIHF. This was followed by infusion of saline (2ml, i.v., n=8/group) or ouabain (25 μ/kg, i. v., n=8/group). Thirty minutes later one-half of the saline and ouabain treated animals (Groups I and II;n =4/group) were given two increasing doses of saline or CK-3197 (0.1 and 0.3 mg/kg, i. v.; n= Groups III and IV; n =4/group) 30 min apart. Hemodynamic paramters were monitored continuously, while myocardial oxygen consumption (MVO₂) was monitored 15 and 30 min after each dose of drug. CK-3197 increased LV DP/dT_max and LV dP/dT_min by 41 and 78%, respectively. Mean arterial pressure increased by 16 and 6%. Heart rate decreased by 6 and 8%, while LV end diastolic pressure (LVEDP) decreased by 3mmHg after CK-3197 (0.3 mg/Kg, i.v.). CK-3197 increased LV work and LV contractile efficiency. Ouabain did not affect the hemodynamic and myocardial energetic profile of CK-3197. These data support the conclusions that CK-3197 is a selective positive inotrope which increases myocardial contractile efficiency in the dog with PIHF without any significant interaction with ouabain.     

芹菜甲素和乙素的抗惊厥作用

1-芹菜甲素(1-3-丁基苯酞)和1-芹菜乙素(1-3-丁基-4,5二氢苯酞)是从芹菜籽分离出的抗惊厥有效成分。在小于TD₅₀剂量下,对最大电休克(MES),最小电休克(MET),戊四唑(MST)和原发听源性惊厥(MAS)等四种动物模型有效,可认为有广泛的抗惊作用。其人工合成的dl-芹菜甲素(dl-3-丁基苯酞)更有抗惊作用强,毒性小和便于推广应用的优点。     

对二甲氨基酚,依地酸二钴和亚硝酸钠对犬心脏血流动力学的影响

本文观察了DMAP,Co_2 EDTA和NaNO_2对犬心脏血流动力学的影响。iv DMAP 3.2mg/kg后LVP及其±dP/dtmax短暂轻度增加,CI,MAP,TPVR,LVWI和HR在30 min内基本稳定,至60 min时CI,LVWI和-dp/dtmax下降。iv Co_2EDTA 15mg/kg或NaNO_2 20 mg/kg后10 min MAP,CI,LVWI,LVP,±dP/dtmax及TPVR(Co_2EDTA组除外)降低最明显,60 min时NaNO_2组CI,MAP,TPVR,LVP和LVWI及Co+2EDTA组CI和LVWI仍然下降。Co_2EDTA组TPVR 1min时下降,5 min见恢复,60min上升。表明(1)DMAP能维持血压和外周血管张力平稳,使心脏舒缩性能短暂轻度增强;(2)Co_2EDTA初期降压系由其扩张血管和抑制心功能所致,后期降压主要由后者引起;(3)NaNO_2降压作用系通过扩张外周血管和抑制心功能所致。     

Therapeutic effects of CPU 86017 on acute and chronic congestive cardiac failure mediated by reducing ET‐1?NOS and oxidative stress in rats

CPU 86017, a derivative of berberine, was administered to rats in which acute and chronic heart failure was induced by left coronary artery ligation for 3 h and 8 weeks, respectively. The rats were divided into the following groups: sham operation, coronary artery ligation (CAL), CAL+ CPU 86017 (80?40 and 20 mg/kg, ig) and CAL+ captopril (60 mg/kg, ig). In the acute model, the systolic parameters of LVSP and LV+dp/dtmax as well as the diastolic parameters of LVEDP and LV‐dp/dtmin improved significantly on pretreatment of CPU 86017 (80 mg/kg). Reductions in elevated serum CPK?LDH?MDA?GOT?GPT?infarcted area and blood viscosity were also significant (P < 0.01). In the chronic model, CPU 86017 (80 mg/kg) preserved the systolic parameters of LVSP and LV+dp/dtmax and the diastolic function of the LVEDP and LV‐dp/dtmin. CPU 86017 completely suppressed elevated plasma ANP and ET‐1, serum and tissue iNOS?NO and MDA, whereas the decreased SOD was improved. CPU 86017 and captopril improved cardiac failure performance and regressed cardiac remodeling in CHF by reducing tissue weight index: lung weight/body weight (BW), right ventricular weight/BW, and left ventricular weight/BW. CPU 86017 exerted beneficial actions in cardiac performance in models of both acute and chronic heart failure, mainly by suppressing ET‐1, iNOS, and oxidative stress in infarcted tissue. Drug Dev Res 63:22–32, 2004. © 2004 Wiley‐Liss, Inc.     

Cardiovascular effects of a new dihydropyridine calcium antagonist

The effects of methyl 2,6-dimethyl-4-(2-nitrophenyl)-5-(2-oxo- 1,3,2-dioxaphosphorinan-2-yl)-1,4-dihydropyridine-3-carboxylate (DHP-218), a 1,4-dihydropyridine derivative, on the cardiovascular system and myocardial oxygen consumption were investigated. Effects on cardiovascular system: In urethane-alpha-chloralose anesthetized dogs, DHP-218 at a dose of 0.01 mg/kg i.v. decreased blood pressure (BP), and at 0.03 mg/kg i.v., long-lasting BP decrease was accompanied by an increase in heart rate (HR), and an increase in blood flow of the coronary, vertebral and internal carotid arteries. No significant changes in myocardial contractile force (MCF) and blood flow of the common carotid and renal arteries were observed. The duration of action was different for various effects. At doses more than 0.05 mg/kg i.d., blood pressure decreased and HR, MCF and the blood flow of coronary and vertebral arteries increased. The effects of nifedipine on the cardiac and regional blood flow were observed at doses more than 0.001 mg/kg i.v. and 1 mg/kg i.d., but the duration of its action was very short compared to those of DHP-218. Effects on cardiohemodynamics: In urethane-alpha-chloralose anesthetized dogs, DHP-218 at a dose of 0.01 mg/kg i.v. produced a decrease in BP and total peripheral resistance (TPR) and an increase in cardiac output (CO). At a dose of 0.03 mg/kg, a decrease in BP and TPR and increases in HR and CO were observed. The duration of action was different for various parameters. No significant changes in dp/dtmax, stroke volume and cardiac work were observed.(ABSTRACT TRUNCATED AT 250 WORDS)     

Cardiovascular effects and plasma levels of denopamine (TA-064), a new positive inotropic agent, in chronically instrumented dogs

Cardiovascular effects of denopamine (TA-064), a new positive inotropic agent, in chronically instrumented dogs were investigated following intravenous and oral administration. In the conscious state, denopamine (0.5-4 micrograms/kg/min, i.v. infusion) increased LV dp/dtmax, cardiac output, stroke volume in a dose-dependent manner, and it decreased left ventricular end-diastolic pressure, total peripheral resistance and PQ interval. Denopamine produced an increase in LV dp/dtmax by 90% at a rate of 4 micrograms/kg/min with slightly increasing systemic blood pressure and heart rate. In the same dogs after anesthetizing with pentobarbital, denopamine in the same dose range showed more marked positive inotropic effects and less changes in cardiac output and total peripheral resistance than in conscious dogs. Other cardiovascular effects of denopamine were qualitatively similar to conscious dogs. These effects of denopamine were diminished by treatment with propranolol. Oral administration of denopamine to conscious dogs (0.1-0.4 mg/kg) produced a rise in LV dp/dtmax dose-dependently, and denopamine at a dose of 0.4 mg/kg increased LV dp/dtmax by 66%, this effect lasting for 7 hr. Heart rate and blood pressure were not affected significantly. Effects on other cardiovascular parameters were changed in the same direction as intravenous administration. The increase in LV dp/dtmax corresponded well with the changes in plasma levels of denopamine in conscious dogs by both intravenous and oral administration. Denopamine showed a selective positive inotropic effect in chronically instrumented dogs, and its positive inotropic action was more marked in the myocardium depressed with an anesthetizing dose of pentobarbital than in the conscious state.     

Behavioral effects of (±) 3,4-methylenedioxyamphetamine (MDA) and (±) 3,4-methylenedioxymethamphetamine (MDMA) in the pigeon: interactions with noradrenergic and serotonergic systems

The effects of three amphetamine analogs were assessed in pigeons key pecking under a multiple 3-min fixed-interval (FI), 30 response fixed-ratio (FR) schedule of food presentation. At doses between 0.1 and 10.0 mg/kg, (±) 3,4-methylenedioxyamphetamine (MDA), (±) 3,4-methylenedioxymethamphetamine (MDMA), and (±)-N-ethyl-3,4-methylenedioxyamphetamine (MDE) either had no effect or decreased response rates in both components of the multiple schedule in a dose-dependent manner. MDA was at least 1 log unit more potent than the other two compounds. Metergoline (0.1–1.0 mg/kg), a serotonin (5-HT) antagonist with comparable affinity for the 5-HT₁ and 5-HT₂ receptor subtypes, blocked the rate-decreasing effects of 3.0 mg/kg MDA in both components of the multiple schedule, but did not affect the MDMA dose-response curve. The 5-HT₂ receptor antagonist ketanserin (0.1–3.0 mg/kg) also restored FI and FR responding that was decreased by 3.0 mg/kg MDA, but had no effect on responding suppressed by MDMA. The noradrenergic alpha-1 antagonist prazosin (0.3–3.0 mg/kg) blocked the behavioral effects of 3.0 mg/kg MDMA at doses that did not attenuate MDA's rate-decreasing effects. These results indicate that although MDA and MDMA are structurally similar and have similar behavioral effects, their actions appear to be mediated through different neurotransmitter systems.