Pierre Duchêne-Marullaz

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The effect of RC-160 (D-Phe-Cys-Tyr-D-Trp-Lys-Val-Cys-Trp-NH2) was studied in mice by means of the hot plate test and in rats with the tail flick test. In mice, 512 micrograms/kg (s.c.) induced an antinociceptive effect maximal (+88 +/- 17%) at the 6th hour after injection but still significant at the 24th hour; 16 micrograms/kg (s.c.) was active for 3 h;(More)
1. In dogs with a 2-4 day old myocardial infarct and a predominantly sinus heart rhythm, we examine arrhythmogenic potencies of amrinone (0.5 mg/kg/min, 1 and 3 mg/kg) and milrinone (10 micrograms/kg/min, 75 and 100 micrograms/kg). 2. Amrinone and milrinone significantly reinduced ventricular ectopic beats on day 2 after coronary occlusion. 3. These effects(More)
Atrial pacing at progressively increasing frequencies was performed in 12 awake dogs through electrodes implanted aseptically in the right atrium and led out through the skin of the neck. Heart rate and the Wenckebach point (the minimum pacing frequency for which a second degree A-V block first appeared) were measured by electrocardiography. The responses(More)
Twenty-four-hour electrocardiograms were recorded in 50 subjects (44 women, 6 men) older than 80 years without cardiovascular disease and with normal standard electrocardiographic responses. During waking and sleeping periods, the mean sinus rates were, respectively, 78 +/- 3 and 64 +/- 1 beats/min; heart rate ranged from 43 to 180 beats/min over 24 hours.(More)
The effects of epinephrine, norepinephrine, and isoproterenol were studied in the nonanesthetized dog with chronic atrioventricular block before and after blockade of cholinergic receptors. Epinephrine and norepinephrine reduced the atrial rate in a reflex manner, whereas isoproterenol increased it. In contrast, all three substances increased(More)
The antiarrhythmic effects of a novel antianginal agent, bepridil, were compared with four reference products. Bepridil increased the effective refractory period in isolated guinea-pig atria slightly more than hydroquinidine, and much more than disopyramide and lidocaine. Amiodarone was without effect. The doses of bepridil necessary for correcting atrial(More)
The chronotropic and inotropic effects of muscarinic receptor agonists (Acetylcholine, Arecoline, Carbachol, Furtrethonium) and antagonists (Atropine, N-methyl and N-butyl scopolammonium, pirenzepine) on isolated guinea-pig atria were studied. All had a greater affinity constants for muscarinic receptors as assessed in terms of inotropic effects than in(More)
The types of interaction of mepyramine (M), diphenhydramin: (D) and eprozinol (E), with histamine H1-receptors of guinea pig ileal and tracheal smooth muscle, were comparatively studied in vitro. According to the concentrations used, all three substances showed an apparent dualist mechanism of action on both preparations when histamine (dihydrochloride) was(More)
The effect of grisorixin, a monocarboxylic ionophore, upon the myocardium-to-background ratio in thallium-201 scintigrams has been studied in 20 dogs. Three sequences of injection and two doses of the ionophore have been used. A significant improvement was obtained when grisorixin was injected 10 min before thallium-201 and at a submaximal dose; the(More)