The antihypertensive effects of verapamil and propranolol were evaluated in 62 patients with mild to moderate systemic hypertension. We also studied the change of 24 hours urinary catecholamines. 31 cases received verapamil and 31 others were treated by propranolol for 4 weeks. Before treating, there were no statistically significant differences (ECG, echocardiology, blood pressure...) noted between the two groups. Conclusions: 1) Blood pressure and heart rate were controlled by verapamil as well as by propranolol. 2) 24 hours urinary catecholamines were reduced by verapamil but not by propranolol
Hypertension ; Verapamil

No abstract available.
Coronary Vasospasm* ; Heart Arrest* ; Verapamil*

No abstract available.
Allopurinol* ; Animals ; Liver* ; Rats* ; Reperfusion Injury* ; Verapamil*

No abstract available.
Animals ; Macrophages, Alveolar* ; Rats* ; Superoxides* ; Verapamil*

Verapamil is highly effective in terminating paroxysmal supraventricular tachycardia(PSVT) by its depressive action on the AV node. In other countries it is already the drug of choice if vagal manevers fail for conversion of PSVT. We evaluated therapeutic efficacy of intravenous verapamil in 30 patients with PSVT who visited Severance Hospital from november 1978 to November 1984. Twenty six of 30 patients(86.7%) had a restoration of normal sinus rhythm by intravenous verapamil without significant side effects. Thus intravenous verapamil is safe and extremely effective in terminating most PSVT.
Atrioventricular Node ; Humans ; Tachycardia, Supraventricular* ; Verapamil*

This study was designed to investigate the effect of substitution of strontium for calcium on mechanical activity in isolated perfused spontaneously beating rat hearts. The mechanical activity of the hearts of Langendorff's preparation in conditions of low calcium and strontium-substitution for calcium was compared. The effect of norepinephrine and verapamil were also observed in those conditions. The results were as follows: 1. In low calcium, the mechanical activity of the heart preparation was significantly reduced, but when the equimolar strontium was substituted for the reduced calcium, the activity was kept at similar level to the normal condition. 2. When equimolar strontium was substituted for the total calcium in perfusate, the heart preparation stopped its beating, and it was not restored in spite of reperfusion with normal calcium perfusate. 3. Norepinephrine-induced positive inotropic effect was inhibited in low-calcium condition especially with low concentration of norepinephrine, but not in strontium-substitution for calcium. 4. Verapamil reduced the activity of the heart both in low-calcium and strontium-substitution as well as in normal calcium conditions. From above results, it was concluded that strontium served as a substitute of calcium in maintaining mechanical activity and in responsiveness to norepinephrine, and the influx of strontium through cell membrane is inhibited by verapamil as the influx of calcium.
Animals ; Calcium ; Cell Membrane ; Heart* ; Norepinephrine* ; Rats* ; Reperfusion ; Strontium* ; Verapamil

No abstract available.
Cyclosporine* ; Drug Resistance, Multiple* ; Humans* ; Lung Neoplasms* ; Lung* ; Tamoxifen* ; Verapamil*

Higenamine is known to possess stimulatory activity on beta-receptor of the heart. Chronotropic actions of higenamic were studied in spontaneously beating right atrial muscle isolated from rabbits. The frequency of spontaneous beating and the relative threshold voltage of the right atrium were examined. The relative threshold voltage was defined as the minimal voltage of the given impulse above which the right atrium could be paced at the frequency of 20% of higenamine was also observed. Higenamine caused the postive chronotropic effect. This response became prominent as the ca2+ concentration in the bathing solution lowered. When tetrodotoxin was added to the bathing solution, the effect of higenemine altered and became similar to that of epinephrine. Higenamine reduced the relative threshold voltage of the right atrium in the bathing solution with [ca2+] of 0.5mM. Such effect was abolished by tetrodotoxin. The effects of verapamill on the spontaneous rate and the relativel threshold voltage were inhibited by higenemine. The above results suggest that, aithough the main action og higenamine is on the Ca channel, higenamine also have a minor effect of augmenting the Na channel.
Baths ; Epinephrine ; Heart ; Heart Atria* ; Heart Rate ; Rabbits ; Tetrodotoxin ; Verapamil

Isometric tension was recorded in uterine arterial ring preparation contracted by potassium (60 mM) and norepinephrine(1.8 X 10(-7) M). With pretreatment of various concentrations of nifedipine(2.9 x 10(-9) ~2.9 X10(-7) M) and verapamil(2.2 X 10(-7) -2.2 X 10(-5) M), the relaxation was dose-dependent and inhibitory effects of both agents were more marked on the potassium than norepinephrine-evoked contraction. After immersion of the arterial preparation in calcium-free solution, the potassium-evoked contraction was decreased to 21+/-4.1%(mean+/-SEM) of the response in normal Krebs solution and norepinephrine-evoked contraction to 26+/-3.8%. The responses to both agents were completely restored when the calcium concentration was increased to 4.0 mM. Pretreated nifedipine(2.9 x 10(-7) M) in calcium-free solution depressed the potassium-evoked contraction to 7.3+/-1.6% and norepinephrine-evoked contraction to 12+/-3.7%. In addition of calcium(0-4.0mM), the potassium-evoked contraction increased to 30+/-4.6% and that by norepinephrine to 45+/-5.4%. Pretreated verapamil(2.2 X 10(-5) M) in calcium-free solution depressed the potassium-evoked contraction to 14+/-3.6% and norepinephrine-evoked contraction to 18+/-3.3%. In addition of calcium(0-4.0mM), the potassium-evoked contraction increased to 41+/-4.2% and that by norepinephrine to 57+/-4.7%. It was concluded that nifedipine and verapamil relaxed KC1 contracted ring in the presence of external calcium and relaxed norepinephrine contracted ring in both the presence and absence of external calcium. These findings suggest that calcium antagonists interfere with the release of calcium from intracellular sites as well as with the slow inward current of calcium.
Calcium ; Humans* ; Immersion ; Nifedipine* ; Norepinephrine ; Potassium ; Relaxation ; Uterine Artery* ; Verapamil*

The effects of diltiazem and verapamil on the electrically-evoked twitch response, train-of- four and tetanic stimulation were studied in the isolated rat hemidiaphragm preparation. Diltiazem(3-150 pM) and verapamil(3-100 pM) increased the electrically-evoked(nerve stimulation, 0.1 Hz, 0.5 ms, 10 V) twitch responses in a dose-related fashion and diltiazem was more potent than verapamil. But, the large doses of diltiazem(150-300 uM) and verapamil(100-300 uM) decreased the twich responses. And the effects of diltiazem and verapamil were not effected by reducing the extracellular calcium from 2.5 to 1.25 mM. Diltiazem and verapamil decreased the train-of-four and tetanus ratio as well as the d-tubocurarine in a dose-related fashion. d-Tubocurarine, a specific nicotinic antagonist, decreased twitch response, and the potentiating twitch response of diltiazem was significantly inhibited by pretreatment of d-tubocura- rine. Furthermore, it is noteworth that the inhibitory effects of d-tubocurararine were markedly potentiated by diltiazem. In cases of the direct(muscle, 0.1 Hz, 5 ms, 10 V) stimulation, diltiazem and verapamil decreaaed the electrically-evoked twitch response with dose dependently. These results indicate that diltiazem and verapamil elicited two distinctive types of twitch response in the rat phrenic-hemidiaphragm preparation. The potentiating effect of twitch response is mediated by the acetylcholine release from the prejunctional nerve terminal and the inhibiting effect may be due to blcking influx of calcium and/or release of acetylcholine from presynaptic nerve terminals.
Acetylcholine ; Animals ; Calcium ; Diltiazem* ; Rats* ; Tetanus ; Tubocurarine ; Verapamil*