地奥心血康对大鼠实验性心肌缺血的保护作用

研究地奥心血康对大鼠实验性心肌缺血的影响。方法：结扎ｗｉｓｔａｒ大鼠左冠状动脉造成急性心肌缺血，设缺血对照组（生理盐水）、地奥心血康组（地奥心血康０．１０ｇ／ｋｇ），阳性药普萘洛尔组（普萘洛尔０．０１ｇ／ｋｇ），各组均在结扎冠脉１５ｍｉｎ后经十二指肠给药，记录给药前后不同时间胸前多导联心电图（９个点），以ΣＳＴ和ＮＳＴ来反映心肌缺血程度和范围，结扎冠脉３ｈ，摘取心脏，用Ｎ—ＢＴ染色确定心肌梗塞面积。结果：地奥心血康０１０ｇ／ｋｇ在３０、６０、１２０、１８０ｍｉｎ使ΣＳＴ分别下降２４％、２９％、３０％、２７％（与对照组比Ｐ＜０．０１、Ｐ＜０．０５）；使ＮＳＴ降低１６％、１７％、１６％、１７％（与对照组比Ｐ＜０．０１）持续１８０ｍｉｎ，使梗塞面积由对照组的１５１４％降到９．６０％（Ｐ＜０．０５）。结论：地奥心血康可降低大鼠实验性心肌缺血程度和缺血范围，减少梗塞面积。     

Dissociation of multiple effects of acute LSD on exploratory behavior in rats by ritanserin and propranolol

Rats tested for 1 h in the Behavioral Pattern Monitor (BPM) after injection of the mixed serotonergic agonistd-lysergic acid diethylamide (LSD) exhibit a behavioral profile similar to that produced by various hallucinogenic 5HT-2 agonists. The characteristic effects of the hallucinogens include suppression of locomotor and exploratory behavior and a preferential decrease in entries into the center of the BPM during the initial half of the test session. After LSD, the initial suppression of responding is followed by a subsequent increase in locomotor activity that is not observed with other serotonergic agonists. In the present studies, the 5HT-1 andβ-adrenergic antagonistd,1-propranolol and the 5HT-2 antagonist ritanserin were administered individually or in combination prior to the acute administration of LSD to test for the involvement of these receptor subtypes in the mediation of the effects of LSD in the BPM paradigm. Propranolol (20 mg/kg) abolished the initial suppression of activity induced by 60 μg/kg LSD without affecting the subsequent increase in locomotion. Conversely, 2.0 mg/kg ritanserin failed to block the initial suppressive effects of 60 or 120 μg/kg LSD, but attenuated the LSD-induced increases in activity during the second half of the session. The combination of propranolol and ritanserin prevented both these effects of LSD. By contrast, the more selective 5HT-2 agonist 2,5-dimethoxy-4-iodoamphetamine (DOI) (0.27 mg/kg) produced an initial suppression of activity in the BPM that was blocked by 2.0 mg/kg ritanserin and was not followed by a subsequent increase in activity. These findings suggest that the initial suppressive effects of LSD in the BPM paradigm are dissociable from the subsequent increases in locomotion and that the two effects are mediated via different serotonergic orβ-adrenergic receptors.     

Influence of adrenergic β-receptor activity on blood flow and free fatty acid release in canine subcutaneous adipose tissue during hemorrhagic shock

Summary Irreversible hemorrhagic shock was produced in dogs by means of a standardized bleeding procedure. Blood flow and net release of free fatty acids were measured in subcutaneous adipose tissue. Infusion of isoprenaline (0.5 g/kg/ min i.v.) prevented the severe vasoconstriction during bleeding and promoted the net release of free fatty acids. Futhermore, isoprenaline infusion made it possible to restore a normal blood flow after reinfusion of the shed blood in contrast to the case in control animals. Propranolol (1 mg/kg i.v.) decreased the arterial free fatty acid concentration in the resting animal and also increased the mortality rate.It is concluded that-receptor stimulation by isoprenaline prevents the vascular damage in canine subcutaneous adipose tissue during development of hemorrhagic shock.This investigation was supported by the Hungarian Medical Research Council and the Swedish Medical Research Council 14X-731-05C, K70-14R-3040.     

Drinking induced by dextran and histamine: relation to kidneys and renin

Intravenous injection of dextran (M.W. 70,000) to rats caused an increased water intake which was accompanied by elevation of plasma renin activity (PRA). The thirst-inducing effect of dextran was abolished by nephrectomy but was unaffected by ureteral ligature. Dextran-induced thirst was blocked by propranolol and by diphenhydramine but the elevation of PRA caused by dextran was not reduced by either of these drugs. Histamine injected subcutaneously to rats increased water intake and elevated PRA. Histamine-induced thirst was only partly reduced after nephrectomy or following administration of propranolol but was completely abolished by diphenhydramine. The elevation of PRA by dextran outlasted the period of increased drinking. The mechanisms involved in the drinking induced by dextran with relation to the kidney, renin and site of action of various blockers are discussed.     

Beta-blockers in hypertensive non-insulin-dependent diabetics: Comparison between penbutolol and propranolol on metabolic control and response to insulin-induced hypoglycemia

Summary In a single blind randomized study the effects of a 4-week administration of propranolol (160 mg/day) and penbutolol (40 mg/day) on metabolic control and insulin-induced hypoglycemia were tested in 8 non-insulin-dependent diabetics with diastolic blood pressure between 95 and 110 mmHg. The recovery from hypoglycemia was not delayed by either drug; hypoglycemic nadir and Conard’sK did not change significantly. Symptoms of hypoglycemia were inhibited to a lesser extent and pulse rate decrease was lower after penbutololvs baseline (65±2.4vs 77±2.4 beats/min, p<0.01) than after propranololvs baseline (61±1.06vs 77±2.4 beats/min p<0.001). Both drugs produced similar and significant effects on blood pressure both systolic and diastolic. There were no significant effects on fasting plasma glucose concentration, HbA_tc, IRI, urinary C-peptide, triglycerides, total and HDL cholesterol and FFA. IRG decreased after penbutololvs baseline 60 min after insulin injection (170±30.8vs 125±15.4 pmol/l, p<0.05). These results indicate that the use of beta-blockers, in particular penbutolol, for mild to moderate hypertension may be considered the treatment of choice also in non-insulin-dependent diabetics at the therapeutic doses employed.     

L—荷包牡丹碱对实验性急性心肌缺血缺氧性损伤的保护作用

静脉注射脑垂体后叶素（ＰＰＨ）诱发３０只豚鼠急性心肌缺血及夹闭小鼠气管后引起心肌撰氧，结果：实验组及阳性对照组与对照组比较，各项指标Ｐ值均〈０．０１。结果提示：Ｌ－荷包牡丹碱１０ｍｇ／ｋｇ ｉｖ和２５ｍｇ／ｋｇ ｉｐ有较强的抗心肌缺血缺氧效应。     

Acute hypotensive effect of combined beta1-adrenoceptor blockade and beta2-adrenoceptor stimulation in spontaneously hypertensive rats (SHR).

The effect on heart rate (HR) and blood pressure (BP) of metoprolol, propranolol and terbutaline, applied alone or in combinations was studied in spontaneously hypertensive rats. Terbutaline had little effect on BP and HR. Propranolol combined with terbutaline had no effect while metoprolol combined with terbutaline decreased BP by 48 mm Hg without affecting HR. Thus the beta2-mediated increase in peripheral vascular resistance after terbutaline was revealed by a drop in BP after beta1-blockade by metoprolol, but not when both beta1-and beta2-receptors were blocked by propranolol.     

Evidence for parallel development of tolerance to the hyperactivating and discoordinating effects of ethanol

Rats maintained on diets containing 6.5% ethanol or equicaloric sucrose solutions were challenged at weekly intervals with 1.5 or 2.0 g/kg ethanol or isotonic saline 14 h after withdrawal from the diet. Tolerance developed to both the hyperactivating (increased line crossing and time active) and discoordinating (disrupted rotarod performance) effects of the 1.5 g/kg dose of ethanol, but was less obvious with the 2.0 g/kg dose. Chlorpromazine (2.5 mg/kg) had a greater depressant effect in animals chronically treated with ethanol, suggesting that some alterations in the functioning of noradrenergic and/or dopaminergic systems may accompany chronic ethanol treatment. However, amphetamine and propranolol did not appear to affect ethanol-and sucrose-treated rats differently. The present studies have therefore shown a parallel development of tolerance to the discoordinating and hyperactivating effects of ethanol and have implicated an underlying noradrenergic and/or dopaminergic mechanism, although the precise nature of the mechanism has not been clarified.     

Inhibiteurs β-adrénergiques et stéréotypies provoquées par l'amphétamine ou l'apomorphine chez le rat

The influence of three beta-adrenergic blocking agents was studied on the stereotyped behavior induced in rats by a range of doses of d-amphetamine or apomorphine. The stereotyped behavior was assessed either clinically (quotation from 0 to 3 at various times for each rat) or using the confinement motor activity test. From 8 mg/kg (i.p.) onwards, propranolol and prinodolol clearly potentiated the amphetamine-induced stereotyped behavior without any modification of the apomorphine-induced stereotyped behavior. Practolol, known for its poor passage through the blood-brain barrier had only a slight effect.

     

窦性心动过速患者左室舒张功能的评价

本文采用脉冲多普勒技术对窦性心动过速患者服用心得安前后的二尖瓣口血流速度频谱进行对比观察，结果表明：自性心动过速时因心率增快导致的血波频谱参数的改变可掩盖舒张功能本身的异常，服用心得安减慢心率后仍存在血流频谱参数异常．则提示左室舒张功能异常。