1989
DOI: 10.1111/j.1476-5381.1989.tb11857.x
|View full text |Cite
|
Sign up to set email alerts
|

Analysis of the hyperpolarizing effect of catecholamines on canine cardiac Purkinje fibres

Abstract: The hyperpolarization induced by catecholamines on barium‐depolarized (0.2–0.8 mm BaCl) canine cardiac Purkinje fibres, in vitro, was studied by use of conventional microelectrode recordings of transmembrane electrical potentials. Noradrenaline, adrenaline and isoprenaline hyperpolarized Purkinje fibres in a concentration‐dependent manner from a threshold concentration around 5 nm. The three catecholamines were shown to be approximately equipotent. Tachyphylaxis was observed when the interval between catechola… Show more

Help me understand this report

Search citation statements

Order By: Relevance

Paper Sections

Select...
3

Citation Types

0
4
0

Year Published

1989
1989
2023
2023

Publication Types

Select...
3

Relationship

0
3

Authors

Journals

citations
Cited by 3 publications
(4 citation statements)
references
References 43 publications
0
4
0
Order By: Relevance
“…Catecholamine stimulates the electrogenic pump in cardiac muscles of bullfrog (AKASU et a!.,1978) and human (IMANISHI and ARITA, 1987), and in rabbit cardiac myocytes (DESILETS and BAUMGARTEN, 1986). There is an alternative explanation that isoproterenol increases the membrane K+ conductance (GADSBY, 1983;NETO and SPERELAKIS, 1989) to increase the Vm. However, it is difficult to explain the increase in 4 by this mechanism.…”
Section: Discussionmentioning
confidence: 99%
See 1 more Smart Citation
“…Catecholamine stimulates the electrogenic pump in cardiac muscles of bullfrog (AKASU et a!.,1978) and human (IMANISHI and ARITA, 1987), and in rabbit cardiac myocytes (DESILETS and BAUMGARTEN, 1986). There is an alternative explanation that isoproterenol increases the membrane K+ conductance (GADSBY, 1983;NETO and SPERELAKIS, 1989) to increase the Vm. However, it is difficult to explain the increase in 4 by this mechanism.…”
Section: Discussionmentioning
confidence: 99%
“…3A). The first effect of the drug (depolarization of Vm) seemed to be due to inhibition of electrogenic (outward) Na-K pump current by DUO, while the late effect, i.e., change of Vm in the hyperpolarizing direction, may be due to long-lasting application of DHO, which increased intracellular Na + and Cat + concentrations, both of which secondarily enhanced membrane K + conductance (ISENBERG, 1976;EISNER et al, H. SAKO et al 1984;KAMEYAMA et al, 1984;NETO and SPERELAKIS, 1989). Thus, in Fig.…”
Section: Discussionmentioning
confidence: 99%
“…Theophylline, a methylxanthine with adenosine receptor antagonistic action directly antagonizing A1A receptors in both the sinoatrial node and AV node, has a similar chronotropic and dromotropic effect to isoproterenol and is available in both intravenous and oral forms. 11 Although literature is sparse, theophylline has reportedly been suggested for treatment of symptomatic bradycardia in the elderly who declined or could not tolerate pacemaker implantation, bradycardia owing to spinal cord injuries, and, most recently, COVID-19-induced bradycardia. 12 No clear guidelines are available regarding the dosing of theophylline for such an indication; however, current literature suggests that a dose between 200 mg and 700 mg daily is sufficient.…”
Section: Discussionmentioning
confidence: 99%
“…They can result from activation of adrenoceptors in nervous terminals and cardiomyocytes with modulation of ganglionic excitability [9] and involvement of serotoninergic structures [2,7] in addition to acetylcholine and catecholamines [5,8].…”
mentioning
confidence: 99%