Einfluß von Beta-Receptorenblockern und verwandten Substanzen auf Erregung, Kontraktion und Energiestoffwechsel der Myokardfaser

Fleckenstein, A.; Döring, H. J.; Kammermeier, H.

doi:10.1007/bf01734125

Cited by 74 publications

(11 citation statements)

References 21 publications

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“…Verapamil does not act therapeutically as a beta-adrenergic blocker (Ross and Jorgensen, 1967;Brichard and Zimmerman, 1970), nor does it have a quinidine-like action (Singh and Vaughan-Williams, 1972); as a calcium-ion antagonist and thus an antagonist of electromechanical coupling (Fleckenstein et al, 1968) it may belong to a novel class of antiarrhythmic agents (Singh and Vaughan-Williams, 1972).…”

Section: Discussionmentioning

confidence: 99%

Immediate Effects of Intravenous Verapamil in Cardiac Arrhythmias

Schamroth¹,

Krikler²,

Garrett³

1972

BMJ

294

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Section: Discussionmentioning

confidence: 99%

Immediate Effects of Intravenous Verapamil in Cardiac Arrhythmias

Schamroth¹,

Krikler²,

Garrett³

1972

BMJ

294

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“…It was strongly negatively inotropic, flattened the plateau of the action potential (Singh & Vaughan Williams, 1972b), and in high concentration reduced Ca uptake by 'sarcoplasmic reticulum' (Fleckenstein, Doring & Kammermeier, 1968), though this was disputed (Graca & van Zweiten, 1971), and its relevance to surface inward Ca-current is highly doubtful. (Olsson, Cotoi & Varnauskas, 1971;Gavrilescu & Cotoi, 1972).…”

Section: Prolongation Ofaction Potential (Class 3 Action)mentioning

confidence: 99%

Investigations to Characterize a New Anti‐arrhythmic Drug, Org 6001, Including a Simple Test for Calcium Antagonism

Salako

Williams

Wittig

1976

British J Pharmacology

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1 The compound Org 6001 (3a-amino-2p-hydroxy-5a-androstan-17-one hydrochloride) was found in recent experiments to exhibit anti-arrhythmic activity. Evidence is presented in this paper concerning its mode of action. 2 Org 6001 was 1.8 times more potent than procaine as a local anaesthetic on desheathed frog nerve. 3 Org 6001 had no effect on the resting potential of isolated cardiac muscle of rabbit, but greatly reduced the maximum rate of depolarization (MRD). The action potential duration (APD) was marginally prolonged in atrial and ventricular muscle. 4 Org 6001 preferentially shortened APD in that part of the Purkinje system in which APD is normally longer than elsewhere, so that APD became more uniform throughout the ventricular conducting system. 5 Org 6001 did not block chronotropic responses to isoprenaline in atrial muscle. 6 Org 6001 had only a small negative inotropic effect in atrial muscle, and did not reduce the positive inotropic effect of raised calcium concentrations. 7 The effect of Org 6001 on MRD was reduced by lowering the external K+ concentration. 8 It is concluded that Org 6001 is an anti-arrhythmic drug of the first class (local anaesthetic type), and within this group is of a sub-class more closely related to lignocaine than to quinidine.

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“…It is known that verapamil and D 600 suppress the influx of Call in the membrane of the smooth muscle and suppress the contraction (19,21,22). These agents strongly suppress the membrane activity of spontaneously active smooth muscle rather than the quiescent muscle.…”

Section: Discussionmentioning

confidence: 99%

Effects of Phthalazinol, Eg 626, on Membrane and Mechanical Properties of Smooth Muscle Cells of Rabbit Main Pulmonary Artery and Superior Mesenteric Artery

Suzuki

Ito

Kuriyama

et al. 1979

Japanese Journal of Pharmacology

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Abstract-Effects of phthalazinol, EG 626, on the membrane and mechanical properties of the vascular smooth muscles, namely superior mesenteric artery and main pulmonary artery of the rabbit were examined. EG 626 (10-'-3 x l0-s g/ml) did not modify the membrane potential (-56.5 nmV), length constant of the tissue (1.47 mm), and rectifying property of the membrane in the pulmonary artery. The membrane potential of the mesenteric artery (-59.8 mV) was also not modified. By treatment with 10-5 g/ml EG 626, the mechanical responses of both muscle tissues induced by either direct muscle stimulation (1 sec pulse) or by nerve stimulation (0.5 msec, 30 Hz) were suppressed. The mechanical response induced by nerve stimulation was more dominantly suppressed than that induced by direct muscle stimulation. Dose-response curve obtained from the relation between noradrenaline and mechanical response in both pulmonary and mesenteric arteries shifted to the right by treatment with 10-s g/ml EG 626. When the depolarization-contraction relationship was observed before and during application of EG 626 (10-s g/ml), using the voltage clamp technique, the application of this agent raised the mechanical threshold to evoke contraction and amplitude of the contraction evoked at any given grade of depolarization was consistently reduced as compared with that evoked in Krebs Solution. These observations suggest that EG 626 suppresses the mobilization of Ca++ during contraction and also the release of chemical transmitter from the nerve terminals by suppression of Ca++ mobilization. EG 626 would thus appear to act on the vascular smooth muscles as a vasodilator.A newly synthesized compound, phthalazinol (EG 626), has been shown to have cyclic AMP phosphodiesterase inhibiting actions on arteries and platelets (1-3). Moreover, this agent also possesses highly potent, reversible and competitive antagonistic effects on throm boxane A2(TXA2) which is known to induce potent arterial contractions in which platelets participate and arterial spasm follows (4-6).Since intracellular free Ca++ concentration is known to regulate the contraction and relaxation of muscles, investigations were carried out to determine whether or not the anti spasmic action of EG 626 on blood vessels is directly produced by relaxation of smooth muscle.To observe the effects of EG 626 on the membrane and mechanical properties of the vascular smooth muscles, the main pulmonary artery and the superior mesenteric artery of the rabbit were used.

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Einfluß von Beta-Receptorenblockern und verwandten Substanzen auf Erregung, Kontraktion und Energiestoffwechsel der Myokardfaser

Cited by 74 publications

References 21 publications

Immediate Effects of Intravenous Verapamil in Cardiac Arrhythmias

Immediate Effects of Intravenous Verapamil in Cardiac Arrhythmias

Investigations to Characterize a New Anti‐arrhythmic Drug, Org 6001, Including a Simple Test for Calcium Antagonism

Effects of Phthalazinol, Eg 626, on Membrane and Mechanical Properties of Smooth Muscle Cells of Rabbit Main Pulmonary Artery and Superior Mesenteric Artery

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