8 结果
1. Ouabain, infused intravenously to anaesthetized guinea-pigs induced ventricular premature beats, ventricular tachyarrhythmias and lethality. 2. Corynanthine (1, 2 and 4 mg kg-1), an alpha 1-adrenoceptor antagonist and idazoxan (100, 200 and 400 micrograms kg-1), an alpha 2-adrenoceptor antagonist
The selectivity of yohimbine and its two diastereoisomers rauwolscine and corynanthine for pre- and postsynaptic alpha adrenoceptors has been investigated in the anesthetized dog. Antagonism of the inhibitory effect of clonidine on the tachycardia produced by electrical stimulation of the ansa
The cardiovascular effects of four yohimbine diastereoisomers, yohimbine, rauwolscine, corynanthine, and 3-epi-alpha-yohimbine, were compared in urethane-anaesthetized and conscious, normotensive Sprague-Dawley rats. Intravenous cumulative infusions (10--500 microgram) of the drugs to anaesthetized
Flutonidine (10, 20 and 40 micrograms/kg) was studied for its efficacy against the cardiotoxic effects induced by slow intravenous infusion of ouabain in guinea-pigs. Flutonidine increased the dose of ouabain required to cause ventricular premature beats, ventricular tachyarrhythmias and lethality.
Azepexole, an alpha 2-adrenoceptor agonist (125, 250 and 500 micrograms/kg i.v.), was examined for its effect on ouabain-induced ventricular premature beats, ventricular tachyarrhythmias and lethality in guinea-pigs. The doses of ouabain required to cause ventricular arrhythmias and lethality were
In isolated perfused rat hearts, global ischaemia for 20 or 40 min led to a substantial decrease of myocardial ATP, creatine phosphate and glycogen, and to an increase in lactate and glucose-6-phosphate. Subsequent coronary reperfusion was associated with severe tachyarrhythmias (ventricular
1 Raubasine was compared with yohimbine and corynanthine in pithed rats. Antagonist activity at alpha 1-adrenoceptors was evaluated on the pressor response to electrical stimulation of the spinal sympathetic outflow and to phenylephrine administration, both being reduced by raubasine in the dose
In pentobarbital-anesthetized rats the left coronary artery was ligated for 5 or 30 min and then opened for reperfusion of the ischemic myocardial area. Twelve min prior to the coronary occlusion yohimbine stereoisomers, namely corynanthine and rauwolscine, or saline solution were given