Die Restitution der Erregungsfortleitung und Kontraktionskraft des K+-gelähmten Frosch- und Säugetiermyokards durch Adrenalin

Engstfeld, G.; Antoni, H.; Fleckenstein, A.; Nast, Alexander; Hattingberg, M. v.

doi:10.1007/bf00362371

Cited by 115 publications

(23 citation statements)

References 13 publications

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“…As shown by Engstfeld, Antoni & Fleckenstein (1961) (Engstfeld et al 1961;Pappano, 1970) in tetrodotoxin containing solutions (Aceves & Erlij, 1967) or in Na-deficient solutions Carmeliet & Vereecke, 1969;Delahayes, 1972), i.e. under conditions which depress or eliminate the excitatory Na current (for references see Reuter, 1973), catecholamines greatly increase the plateau height and may produce slowly conducted action potentials.…”

Section: Voltage Clamp Experimentsmentioning

confidence: 99%

Localization of beta adrenergic receptors, and effects of noradrenaline and cyclic nucleotides on action potentials, ionic currents and tension in mammalian cardiac muscle

Réuter¹

1974

The Journal of Physiology

407

120

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Section: Voltage Clamp Experimentsmentioning

confidence: 99%

Localization of beta adrenergic receptors, and effects of noradrenaline and cyclic nucleotides on action potentials, ionic currents and tension in mammalian cardiac muscle

Réuter¹

1974

The Journal of Physiology

407

120

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“…This important question was further tested by repeating methods formerly described by Engstfeld, Antoni & Fleckenstein (1961) and Carmeliet & Vereecke (1969). In our experiment (Figure 8 reached a maximum value which was slightly less than 50% of that found for (±)-isoprenaline ( Figure 3).…”

Section: Drugsmentioning

confidence: 52%

THE EFFECTS OF ISOPRENALINE AND A NEW p‐SYMPATHOMIMETIC AMINE UPON SPONTANEOUS ACTIVITY, DIASTOLIC DEPOLARIZATION AND PLATEAU HEIGHT IN CARDIAC PURKINJE FIBRES

Grabowski

Lüttgau

Schulze

1978

British J Pharmacology

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1 In spontaneously active Purkinje fibres of young cows the dose-response curves of the action of isoprenaline upon different electrophysiological parameters were measured. 2 The increase in slope of diastolic depolarization could roughly be described by a one-for-one binding curve with a half maximum effect near 10-8 M and the increase in the height of the plateau level by a two-for-one binding curve with a half maximum effect near 10' M (-)-isoprenaline.3 These dose-response curves were similar to those of two parameters measured under voltage clamp conditions by other authors. The increase in slope of diastolic depolarization behaved like the shift of the activation curve for the pacemaker potassium current towards positive potentials and the growth in plateau height like the increase in the slow inward current mainly carried by Ca ions. From this conformity we propose that the parameters evaluated by us from action potential records could be used for a qualitative analysis of the action of catecholamines on pacemaker potassium current and Ca influx. 4 The effects of the isomers of a new drug, 1-isopropylamino-3(4'hydroxyphenoxy)-propan-2-ol (IHP), were evaluated in the same way as those of isoprenaline. The (-)-isomer was at optimal concentrations (10'5 M) nearly half as effective as isoprenaline in increasing frequency and slope of diastolic depolarization but caused no increase in plateau height. An identical relationship, but at 5 to 10 times higher concentrations, was obtained with the (+)-isomer. 5 When 10-M(-)-IHP was added to a preparation equilibrated with a maximum dose of (-)-isoprenaline (10-6 M), frequency and plateau height declined. This result together with the observation that the effects of IHP could be blocked by the specific f-antagonist propranolol, revealed the ,B-agonistic nature of the new drug. Its inefficiency in increasing the plateau height and thus the slow (Ca) inward current was explained by its relatively low potency and intrinsic activity.

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“…They reported that increases in extra cellular potassium concentration to levels still compatible with propagated excitation caused variable changes in the contractile force of mammalian cardial muscle; i.e., a negative inotropic effect (Engstfeld et al 1961;Sarnoff et al 1966;Kavaler et al 1972), no inotropic effect (Goodyer et al 1964), or a positive inotropic effect (Kavaler et al 1972), In this study, potassium chloride induced only a negative inotropic effect in all trials. It was suggested that the negative inotropic effect of potassium can be attributed mainly to a potassium-induced reduction in the amplitude and/or duration of the action potential plateau (Kavaler et al 1972).…”

mentioning

confidence: 45%

Positive chronotropic and negative inotropic effects induced by potassium chloride in the isolated canine atrium.

Chiba

1976

Tohoku J. Exp. Med.

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Die Restitution der Erregungsfortleitung und Kontraktionskraft des K+-gelähmten Frosch- und Säugetiermyokards durch Adrenalin

Cited by 115 publications

References 13 publications

Localization of beta adrenergic receptors, and effects of noradrenaline and cyclic nucleotides on action potentials, ionic currents and tension in mammalian cardiac muscle

Localization of beta adrenergic receptors, and effects of noradrenaline and cyclic nucleotides on action potentials, ionic currents and tension in mammalian cardiac muscle

THE EFFECTS OF ISOPRENALINE AND A NEW p‐SYMPATHOMIMETIC AMINE UPON SPONTANEOUS ACTIVITY, DIASTOLIC DEPOLARIZATION AND PLATEAU HEIGHT IN CARDIAC PURKINJE FIBRES

Positive chronotropic and negative inotropic effects induced by potassium chloride in the isolated canine atrium.

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