莨菪类药物对大鼠脑,心肌血流量和心指数的影响

采用放射性生物微球法观察了莨菪类药物(HD)对大鼠脑血流量(CBF)、心肌血流量(MBF)和心指数(C1)的影响.结果表明HD明显增加CBF和MBF。减小CI.本文三种药物增加大脑半球 CBF作用随剂量增加而增强,Ani10～40 mg·kg~(-1)iv增加26～73％;东莨菪碱(Sco)1.25～5mg·kg~(-1)iv增加17～38％;阿托品(Atr)2.5～10mg·kg~(-1)iv增加17～64％,HD增加MBF作用远较增加CBF作用强.Ani 10～20 mg·kg~(-1)iv增加128～198％;但40 mg·kg~(-1)iv作用明显减弱;Sco 1.25～5mg·kg~(-1)iv增加5l～116％;Atr 5～10 mg·kg~(-1)iv增加113～137％,三药均可明显减小CI。     

山莨菪碱对脑缺血局部血流量的影响

用放射性生物微球法,观察了山莨菪碱对双侧颈总动脉结扎(BCAL)后大鼠脑局部血流量的影响.BCAL使大鼠大脑半球血流量显著减少,以中部最明显。山莨菪减10mg·kg~(-1)iv明显增加缺血最严重的大脑中部血流量,20mg·kg~(-1)iv明显增加整个大脑半球血流量,40mg·kg~(-1)iv则作用减弱。BCAL后心肌血流量明显增加,山莨菪碱20mg·kg~(-1)iv使其进一步增加,但40mg·kg_(-1)iv则使其显著减少。10～20·mg·kg~(-1)iv对BCA L后的心指数无明显影响,40mg·kg~(-1)iV则使其明显增大。     

Kappa-晒化卡拉胶对实验动物的抗心律失常作用

Kappa-硒化卡拉胶是一含硒有机化合物。ip 9 mg·kg~(-1)·d~(-1)×5d或单次ig 35,70,140mg·kg~(-1)能显著提高乌头碱致大鼠HA的阈剂量,此作用可与Na_2SeO_3 1 mg·kg~(-1)·d~(-1)×5d ip比拟.随着Kappa-硒化卡拉胶ig剂量增加,尚可提高乌头碱所致VE,VT和VF的阈剂量。ip 9mg·kg~(-1)·d~(-1)×5 d或ig 70mg·kg~(-1)能提高BaCl_2致大鼠或哇巴因致豚鼠HA的阈剂量。对BaCl_2致大鼠VF或哇巴因致豚鼠VE的阈剂量,分别在ig70mg·kg~(-1)与140mg·kg~(-1)时有提高,而ipNa_2SeO_3 1 mg·kg~(-1)·d~(-1)×5d无此明显影响。     

13-正丙基巴马汀的抗心律失常作用

iv13—正丙基巴马汀(13—n—Ptopyl—Pal-matine)8mg·kg~(-1)能显著减少氯仿诱发小鼠室颤的发生率.提高哇巴因致豚鼠室早、室速、室颤及心搏停止的阈剂量。iv1、3 mg·kg~(-1)可明显减少CaCl_2诱发小鼠心律失常的发生率.缩短BaCl_2诱发大鼠心律失常的持续时间、但对乌头碱诱发大鼠心律失常无明显的对抗作用。此外,13—正丙基巴马汀还能明显提高大鼠心肌细胞膜Na~+,K~+—ATP酶的活性。     

磷酸喹哌抗实验性心律失常作用

磷酸喹哌(PQP)9mg·kg~(-1)iv明显降低小鼠室颤的死亡率;PQP 18mg·kg~(-1)ip对氯仿诱发小鼠室颤具有保护作用;PQP 6.3mg·kg~(-1)ip显著增加恒速(10mg·L~(-1)·min~(-1)滴注乌头碱引起麻醉大鼠室性早搏(VE)、室性心动过速(VT)、室性纤颤(VF)所需的乌头碱用量;PQP5.4 mg·kg~(-1)iv显著增加恒速(50mg·L~(-1)·min~(-1))滴注哇巴因引起麻醉豚鼠VE、VT和VF所需哇巴因用量;PQP3.36mg·kg~(-1)iv明显缩短肾上腺素诱发家兔室性心律失常的持续时间.结果表明PQP具有抗心律失常作用。小鼠PQPLD_(50)iv为93.33 mg·kg~(-1)。     

西那沙星对幼龄大鼠的软骨毒性

目的:观察西那沙星(sinafloxacin)静脉注射对幼龄大鼠关节软骨的影响。方法:40只大鼠,雌雄各半,按照体重随机分为西那沙星低、高剂量组(iv,10和60 mg·kg~(-1))、加替沙星阳性对照组(iv,60 mg·kg~(-1))和空白对照组(iv生理氯化钠溶液10 mL·kg~(-1))。各组连续给药7 d。d7给药后24 h处死动物取完整膝、髋关节进行病理组织学检查。结果:西那沙星可使幼龄大鼠膝、髋关节软骨表层幼稚软骨细胞数量减少,骨骺软骨细胞变性坏死,且存在量效关系。结论:西那沙星10～60 mg·kg~(-1)连续iv 7 d对幼龄大鼠关节软骨有破坏作用。     

氢溴酸高乌甲素量—效关系的实验研究

<正> 高乌甲素(拉帕乌头碱Lappaconitine)是从毛莨科乌头属植物(Aconiton sinomontanum Nakai)分离得到的一种二(竹帖)类生物碱。我们对该药的临床有效剂量和毒性及与扑热息痛的协同作用进行了实验,以期给临床推荐安全有效的给药剂量。实验使用昆明种小鼠,兼用,采用两种给药途径(po.iv),按Bliss法计算小鼠poLD_(50)为28.61mg·kg~(-1)(可信限25.07～32.65),iv LD_(50)8.59mg·kg~(-1)(8.04～9.09)。按Bliss法计算,小鼠扭体镇痛法测得高乌甲素ivED_(99)为4.75mg·kg~(-1)(3.92～5.75),ED_(50)为3.5mg·kg~(-1)(3.30～3.71),ED_1为2.57mg·kg~(-1)(2.16～3.08)。换算成相应人的剂量分别为23.32,17.18,13.18 1/60mg·kg~(-1).poED_(90)为16.40mg·kg~(-1)(13.79～23.32).ED_(50)为11.40mg·     

芍药甙在兔和大鼠体内的药动学研究

兔iv25mg·kg~(-1)芍药甙后,血药浓度—时间曲线符合二室模型。药动学参数为T_(1/2α)=5.93min,T_(1/2β)66.02min,V(?)=516.8ml·kg~(-1),CL=6.11ml·kg~(-1)·min~(-1)。兔ig250mg·kg~(-1)芍药甙,生物利用度为F=7.24％±4.15％,T_(max)=77.4min,C_(max)=21.57mg·L~(-1)大鼠ig550mg·kg~(-1)芍药甙,24h内粪、尿排泄量及iv55mg·kg~(-1)7h内胆汁排泄量分别占给药量的10.61％、1.08％、864％。离体肝脏灌流结果提示:芍药甙在肝内代谢少.     

小檗碱对在体心室纤颤阈和心肌细胞动作电位的作用以及自主神经的影响

小檗碱(Ber)1～4 mg·kg~1 iv明显提高兔的VFT,迷走神经切断或利血平3mg·kg~1 ip并不影响Ber提高VFT的作用,提示Ber抗心律失常的作用可能与自主神经无关,对兔在体心室肌细胞动作电位,Ber 1 mg·kg~1 iv的主要作用是降低V_(max),较高剂量(4 mg·kg~1)iv亦能延长APD_(90)和APD_(100),Ber1～4mg·kg~1 iv后,迷走神经或交感神经刺激引起的APD缩短作用减弱或消失,并抑制交感神经刺激诱发的DAD和触发活动,这些亦可能是Ber抗心律失常作用的机理。     

赛拉嗪对小鼠胃肠运动及大鼠胃肠电的影响

育亨宾(0.5～4mg·kg~(-1),sc)和苯口恶咪唑(2～8 mg·kg~(-1).sc)剂量依赖性地拮抗赛拉嗪(4mg·kg~(-1),sc)对小鼠胃肠推进运动的抑制作用.赛拉嗪(2、4 mg·kg~(-1),sc)可乐定(120μg·kg~(-1),sc)抑制大鼠胃、十二指肠、空肠、回肠的肌电活动,用药后30min作用最显著。育亨宾(4 mg·kg~(-1),sc)一定程度地拮抗赛拉嗪(4 mg·kg~(-1),sc)抑制胃肠肌电活动的作用.     

促甲状腺激素释放激素对兔创伤性休克的影响

ＴＲＨ０．２２～２ｍｇ·ｋｇ－１ｉｖ使创伤性休克兔血压迅速回升，持续２０ｍｉｎ基本稳定不变。首次ｉｖＴＲＨ和以０．６７ｍｇ·ｋｇ－１·ｈ－１连续静脉输入使休克兔血压在５ｈ内维持在较高水平，同时提高５ｈ存活率。ＴＲＨ亦能对抗休克时的心率减慢及脉压缩小。但快速ｉｖＴＲＨ明显加速休克兔的死亡。     

促甲状腺素释放激素改善失血性休克心功能的作用机理

TRH iv后显著升高失血性休克家兔MAP,±dP/dt_(max),Vpm,V_(max)和血浆E。利血平预处理后,TRH的上述作用消失。β受体阻滞剂普萘洛尔预处理后,TRH增强±dP/dt_(max),Vpm和V_(max)的作用消失,并在iv TRH后20和30 min取消了TRH的升压作用。α受体阻滞剂酚苄明预处理后,TRH仍能升高MAP,±dP/dt_(max),Vpm和V_(max)。离体大鼠左心房实验证明TRH(0.1mmol/L)可显著增强异丙肾上腺素和多巴胺的正性肌力作用。     

Aminoguanidine attenuates the delayed circulatory failure and improves survival in rodent models of endotoxic shock.

1. We have investigated the effects of aminoguanidine, a relatively selective inhibitor of the cytokine-inducible isoform of nitric oxide synthase (iNOS), on the delayed circulatory failure, vascular hyporeactivity to vasoconstrictor agents, and iNOS activity in a rat model of circulatory shock induced by bacterial endotoxin (E. coli lipopolysaccharide; LPS). In addition, we have evaluated the effect of aminoguanidine on the 24 h survival rate in a murine model of endotoxaemia. 2. Male Wistar rats were anaesthetized and instrumented for the measurement of mean arterial blood pressure (MAP) and heart rate (HR). Injection of LPS (10 mg kg-1, i.v.) resulted in a fall in MAP from 115 +/- 4 mmHg (time 0, control) to 79 +/- 9 mmHg at 180 min (P < 0.05, n = 10). The pressor effect of noradrenaline (NA, 1 microgram kg-1, i.v.) was also significantly reduced at 60, 120 and 180 min after LPS injection. In contrast, animals pretreated with aminoguanidine (15 mg kg-1, i.v., 20 min prior to LPS injection) maintained a significantly higher MAP (at 180 min, 102 +/- 3 mmHg, n = 10, P < 0.05) when compared to rats given only LPS (LPS-rats). Cumulative administration of aminoguanidine (15 mg kg-1 and 45 mg kg-1) given 180 min after LPS caused a dose-related increase in MAP and reversed the hypotension. Aminoguanidine also significantly alleviated the reduction of the pressor response to NA: indeed, at 180 min, the pressor response returned to normal in aminoguanidine pretreated LPS-rats.(ABSTRACT TRUNCATED AT 250 WORDS)     

Involvement of the sympathetic nervous system in the cardiovascular effects of ACTH-(1-24) during hemorrhagic shock in rats

Summary In urethane-anesthetized rats, removal of about 50% of the total blood volume over a period of 25 – 30 min caused hypovolemic shock, with extreme hypotension (MAP = 18–25 mmHg and death of all animals within 22±5 min. The i.v. injection of ACTH-(1-24) in the dose range of 40–160 g/kg induced a sustained, dose-dependent, and, at the highest dose used, an almost complete recovery of blood pressure, and 100% survival, at least for 2 h after treatment. The effect of ACTH-(1–24) was completely prevented by reserpine (5 mg/kg) and clonidine (0.1 mg/kg), significantly reduced by prazosin (0.1 mg/kg), dibenamine (15 mg/kg) and i.v. yohimbine (1 mg/kg) and unaffected by i.c.v. yohimbine (0.2 mg/kg) and i.v. practolol (15 mg/kg). These data suggest that the effect of ACTH-(1–24) in hypovolemic shock depends on the functional integrity of the sympathetic nervous system and is mediated through an activation of peripheral alpha-adrenoceptors.Abbreviations MAP mean arterial pressure - PP pulse pressure - i.c.v. intracerebroventricular Send offprint requests to A. Bertolini at the above address     

Cloricromene, a coumarine derivative, protects against lethal endotoxin shock in rats.

Endotoxin shock was induced in male rats by an intravenous (i.v.) injection of Salmonella enteriditis lipopolysaccharide (LPS; 20 mg/kg i.v.). Survival rate, macrophage and serum tumor necrosis factor (TNF-alpha), mean arterial blood pressure (MAP) and white blood cell count were then evaluated. Furthermore the in vitro effect of cloricromene on peritoneal macrophage phagocytosis and TNF-alpha release by primed peritoneal macrophages was investigated. LPS administration caused animal death (0% survival 24 h after endotoxin challenge), hypotension, marked leukopenia and increased the levels of TNF-alpha in both serum and macrophage supernatants. Cloricromene administration (0.5, 1 and 2 mg/kg i.v. 15 min after endotoxin) protected against LPS-induced lethality (100% survival rate 24 h after endotoxin challenge), reverted LPS-induced hypotension and leukopenia, and decreased TNF-alpha in both serum and macrophage supernatants. Finally, cloricromene, added in vitro to peritoneal macrophages collected from endotoxin-treated rats increased macrophage phagocytosis and reduced TNF-alpha formation by activated mononuclear phagocytes. Our data suggest that cloricromene increases survival rate in endotoxin shock through an inhibition of TNF-alpha production.     

胡黄连苷元（香荚兰乙酮）对失血性休克及内毒素诱导“两次打击”损伤的保护作用

目的:评价胡黄连苷元对大鼠“两次打击”损伤的保护作用.方法:采用大鼠“两次打击”损伤模型(失血性休克40 mmHg 45 min后iv细菌内毒素LPS 150 μg/kg).大鼠随机分为七组:对照组,内毒素组,失血组,失血/内毒素组和失血/内毒素 胡黄连苷元(2.5,5.0,10.0 mg/kg)组.胡黄连苷元溶于复苏液(生理盐水,NS)中并在2 h内经静脉给药。在LPS或NS注射后,观察大鼠8,16,24及48 h存活率;检测肺组织(iv LPS后3 h及6 h)及血清(失血前,失血后及iv LPS/NS后0,0.5,1,2,4,6 h)丙二醛含量;检测肺及肝组织(iv LPS/NS后 3 h及 6 h)髓过氧化物酶活性.结果:与对照组比较,“两次打击”损伤大鼠8 h(64.3％,P<0.05),16 h(35.7％,P<0.01),24 h(28.6％,P<0.01),48 h(14.3％,P<0.01)存活率显著降低;血清及肺组织丙二醛含量显著增多,肺、肝组织髓过氧化物酶活力显著升高.胡黄连苷元剂量依赖性升高失血性休克大鼠平均动脉压(P<0.05),提高大鼠存活率,降低血清及组织丙二醛含量,下调肺及肝组织髓过氧化物酶活力.结论:胡黄连苷元可保护由失血性休克及细菌内毒素诱导的大鼠“两次打击”损伤.     

静脉注射不同阿片肽拮抗物抗大鼠烫伤休克效果的比较

在大鼠20%体表面积Ⅲ°烫伤后,立即从静脉分别注射beta-内啡肽抗血清10μl,ICI_(174864) 0.2mg,TRH 2mg,或纳洛酮2mg,随后在1,2,3h再分别给予半量,观察心血管功能指标和存活时间。结果表明,beta-内啡肽抗血清、ICI_(174864)和纳洛酮,均可改善烫伤动物的心功能指标,延缓MAP下降和HR减慢,尤其beta-内啡肽抗血清可显著延长动物的存活时间。TRH在早期能增加烫伤动物的心率,延缓MAP的下降,晚期却加快了MAP的下降,对心功能指标几无改善。这提示beta-内啡肽抗血清、ICI_(174864)和纳洛酮,均有抗烫伤休克的作用;TRH如何适当地应用于抗烫伤休克,有待进一步探讨。     

Effects of dexamethasone and SB 209670 on the regional haemodynamic responses to lipopolysaccharide in conscious rats.

1. Male (350-450 g) Long Evans rats were chronically instrumented to permit regional haemodynamics to be monitored in the conscious state. In the first experiment, either saline (0.4 ml h-1) or dexamethasone (3 mg kg-1, 125 micrograms kg-1 h-1) was infused continuously for 24 h, before co-infusion of lipopolysaccharide of (LPS, 150 micrograms kg-1 h-1) for 24 h. Dexamethasone prevented the delayed (5-24 h) fall in mean arterial blood pressure (MAP) and the renal and hindquarters vasodilatation seen with LPS infusion alone, but not the initial (about 2 h) fall in MAP or renal vasodilatation. However, at this dose, dexamethasone itself caused a significant rise in MAP and regional vasoconstrictions. 2. In the second experiment, dexamethasone at a lower dose (12.5 micrograms kg-1 h-1) had only slight pressor and vasoconstrictor effects. However, in its presence, infusion of LPS caused a substantial and progressive rise in MAP (maximum at 8 h, +32 +/- 3 mmHg) together with persistent mesenteric and hindquarters vasoconstriction and a transient renal vasodilatation. 3. In the third experiment, the non-selective endothelin antagonist, SB 209670 (600 micrograms kg-1 h-1), blocked the slight pressor and regional vasoconstrictor effects of the lower dose of dexamethasone. Furthermore, in the presence of dexamethasone and SB 209670, infusion of LPS caused marked, but transient hypotension (nadir at 5 h, -24 +/- 2 mmHg) and renal and mesenteric vasodilatation. 4. At the end of all experimental protocols, sequential administration of the AT1-receptor antagonist, losartan, followed by the V1-receptor antagonist, (+)-(CH2)5-O-Me-Tyr, vasopressin, caused effects indicating a variable involvement of angiotensin and vasopressin in the maintenance of cardiovascular status. 5. Collectively, the results indicate that, in the conscious rat, dexamethasone interacts with vasoconstrictor and vasodilator mechanisms, and hence its influence on the haemodynamic responses to LPS cannot be attributed, simply, to inhibition of the activity of inducible nitric oxide synthase and/or cyclo-oxygenase-2.     

Haemodynamic effects of dicentrine, a novel alpha 1-adrenoceptor antagonist: comparison with prazosin in spontaneously hypertensive and normotensive Wistar-Kyoto rats.

1. The haemodynamic effects of dicentrine, an aporphine derivative isolated from the plant Lindera megaphylla, were investigated and compared with prazosin in rats. 2. In anaesthetized normotensive Wistar-Kyoto (WKY) rats, i.v. administration of dicentrine (0.1, 0.5, 1.0 mg kg-1) and prazosin (0.01, 0.05, 0.1 mg kg-1) induced a dose-related reduction of mean arterial pressure (MAP) which reached a maximal effect 5-10 min after injection and persisted for 2 h. 3. In anaesthetized WKY rats, a higher dose of dicentrine (1.0 mg kg-1, i.v.) did not cause any significant changes in heart rate (HR), cardiac output (CO) and stroke volume (SV) but markedly increased tail blood flow. In contrast, a higher dose of prazosin (0.1 mg kg-1, i.v.) produced a decrease in HR which paralleled the time course of the hypotensive response. 4. The hypotensive activity of dicentrine was completely abolished by alpha-adrenoceptor blockade. Both dicentrine and prazosin significantly attenuated pressor responses to noradrenaline but failed, even at maximal hypotensive doses, to impair the pressor effects of angiotensin II or vasopressin. These observations suggest that dicentrine appears to exert its hypotensive action through alpha 1-adrenoceptor blockade. 5. In conscious normotensive and spontaneously hypertensive (SH) rats, dicentrine (0.5-2.0 mg kg-1, i.v.) and prazosin (0.05-0.2 mg kg-1, i.v.) also evoked dose-related decreases in MAP which were of greater magnitude in SH rats. Oral administration of dicentrine (5 and 8 mg kg-1) to conscious SH rats caused a hypotensive effect which persisted for over 15 h.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of the endothelin receptor antagonist, SB 209670, on circulatory failure and organ injury in endotoxic shock in the anaesthetized rat.

1. This study investigates the effects of the non-selective ETA/ETB receptor antagonist, SB 209670, on systemic haemodynamics, renal function, liver function, acid-base balance and survival in a rat model of endotoxic shock. 2. Injection of E. coli lipopolysaccharide (LPS, 10 mg kg-1, i.v.) resulted in increases in the serum levels of tumour necrosis factor-alpha (TNF-alpha, maximum 60 min after LPS), endothelin-1, (ET-1; maximum 120 min after LPS), and interferon-gamma (IFN-gamma, maximum 180 min after LPS). 3. Injection of LPS also resulted in a fall in blood pressure from 113 +/- 3 mmHg (time = 0) to 84 +/- 4 mmHg at 360 min (n = 15) as well as a hyporeactivity to the vasoconstrictor responses elicited by noradrenaline (NA, 1 microgram kg-1, i.v.). Pretreatment of rats with a continuous infusion of SB 209670 (3 mg kg-1, i.v. bolus + 100 micrograms kg-1, i.v. infusion commencing 15 min prior to LPS) significantly augmented the hypotension as well as the vascular hyporeactivity to NA caused by endotoxaemia. 4. Pretreatment of LPS-rats with SB 209670 (3 mg kg-1, i.v. bolus given 15 min prior to LPS) or infusion of SB 209670 (bolus dose and infusion as above) resulted in a reduction in 6 h-survival from 71% (control) to 30% and 13%, respectively. 5. Endotoxaemia for 4 h resulted in rises in the serum levels of urea and creatinine (indicators of renal failure), but not in the serum levels of bilirubin, GPT and GOT (indicators of liver dysfunction and/or hepatocellular injury). Pretreatment of LPS-rats with SB 209670 (3 mg kg-1, i.v. bolus 15 min prior to LPS) significantly augmented the serum levels of creatinine, bilirubin, GPT and GOT caused by endotoxin. In addition, endotoxaemia caused, within 15 min, an acute metabolic acidosis (falls in pH, HCO3- and base excess) which was compensated by hyperventilation (fall in PaCO2). Pretreatment of LPS-rats with SB 209670 (3 mg kg-1, i.v. bolus) significantly augmented the metabolic acidosis caused by LPS. 6. Thus, the non-selective ETA/ETB receptor antagonist, SB 209670, augments the degree of (i) hypotension, (ii) vascular hyporeactivity to noradrenaline, (iii) renal dysfunction and (iv) metabolic acidosis caused by endotoxin in the anaesthetized rat. In contrast to rats treated with LPS alone, LPS-rats treated with SB 209670 exhibited liver dysfunction and hepatocellular injury. We propose that the release of endogenous ET-1 serves to maintain blood pressure and subsequently organ perfusion in septic shock.