EurekaMag
+ Translate
+ Most Popular
Gaucher's disease;thirty-two years experience at Siriraj Hospital
A study of Macrobathra Meyrick from China (Lepidoptera, Cosmopterigidae)
First occurrence in ores of tetragonal chalcocite
Effects of trace element nutrition on sleep patterns in adult women
N.Z. range management guidelines. 2. Design of grazing management systems for tussock country
A case of lipoma of the esophagus
A revision of world Acanthosomatidae (Heteroptera: Pentatomidae): keys to and descriptions of subfamilies, tribes and genera, with designation of types
Life history of the coronate scyphozoan Linuche unguiculata (Swartz, 1788)
Perceptual restoration of obliterated sounds
Mutagenicity studies on two chromium(III) coordination compounds
The formation of the skeleton. I. Growth of a long bone. 1st appearance of a center of calcification
Leucopenia and abnormal liver function in travellers on malaria chemoprophylaxis
The joint commission: four key root causes loom large in sentinel event data
Treatment of vitiligo with topical 15% lactic acid solution in combination with ultra violet-A
Behaviour of dairy cows within three hours after feed supply: I. Influence of housing type and time elapsing after feed supply
Observations of the propagation velocity and formation mechanism of burst fractures caused by gunshot
Management and control of patients with type 2 diabetes mellitus in Lebanon: results from the International Diabetes Management Practices Study (IDMPS)
The diet composition and nutritional knowledge of patients with anorexia nervosa
Physoporella croatica Herak, 1958 of the Slovak karst Anisian (Slovakia, the West Carpathians Mts.)
Bright lights, big noise. How effective are vehicle warning systems?
Ein Plesiosaurier-Rest mit Magensteinen aus mittlerem Lias von Quedlinburg
Incidence of Chlamydia trachomatis in patients with sterility
Monster soup: the microscope and Victorian fantasy
Preliminary tests with residual sprays against poultry lice
Duration of the life of plants in phylogeny

Increased sodium/calcium exchanger activity enhances beta-adrenergic-mediated increase in heart rate: Whole-heart study in a homozygous sodium/calcium exchanger overexpressor mouse model


Increased sodium/calcium exchanger activity enhances beta-adrenergic-mediated increase in heart rate: Whole-heart study in a homozygous sodium/calcium exchanger overexpressor mouse model



Heart Rhythm 14(8): 1247-1253



ISSN/ISBN: 1547-5271

PMID: 28495655

DOI: 10.1016/j.hrthm.2017.05.001

The cardiac sodium/calcium (Na+/Ca2+) exchanger (NCX) contributes to diastolic depolarization in cardiac pacemaker cells. Increased NCX activity has been found in heart failure and atrial fibrillation. The influence of increased NCX activity on resting heart rate, beta-adrenergic-mediated increase in heart rate, and cardiac conduction properties is unknown. The purpose of this study was to investigate the influence of NCX overexpression in a homozygous transgenic whole-heart mouse model (NCX-OE) on sinus and AV nodal function. Langendorff-perfused, beating whole hearts of NCX-OE and the corresponding wild-type (WT) were studied ± isoproterenol (ISO; 0.2 μM). Epicardial ECG, AV nodal Wenckebach cycle length (AVN-WCL), and retrograde AVN-WCL were obtained. At baseline, basal heart rate was unaltered between NCX-OE and WT (WT: cycle length [CL] 177.6 ± 40.0 ms, no. of hearts [n] = 20; NCX-OE: CL 185.9 ± 30.5 ms, n = 18; P = .21). In the presence of ISO, NCX-OE exhibited a significantly higher heart rate compared to WT (WT: CL 133.4 ± 13.4 ms, n = 20; NCX-OE: CL 117.7 ± 14.2 ms, n = 18; P <.001). ISO led to a significant shortening of the anterograde and retrograde AVN-WCL without differences between NCX-OE and WT. This study is the first to demonstrate that increased NCX activity enhances beta-adrenergic increase of heart rate. Mechanistically, increased NCX inward mode activity may promote acceleration of diastolic depolarization in sinus nodal pacemaker cells, thus enhancing chronotropy in NCX-OE. These findings suggest a novel potential therapeutic target for heart rate control in the presence of increased NCX activity, such as heart failure.

Please choose payment method:






(PDF emailed within 0-6 h: $19.90)

Accession: 059850566

Download citation: RISBibTeXText

Related references

Integrin-mediated membrane blebbing is dependent on sodium-proton exchanger 1 and sodium-calcium exchanger 1 activity. Journal of Biological Chemistry 287(13): 10316-10324, 2012

Sodium-calcium exchanger overexpression in the heart--insights from a transgenic mouse model. Basic Research in Cardiology 97(Suppl 1): I31-I35, 2002

Expression of the sodium, calcium exchanger in a diverse tissues: A study using the cloned human cardiac sodium, calcium exchanger. American Journal of Physiology 263(6 Part 1): C1241-C1249, 1992

Effects of developmental changes in heart rate and action potential duration on the cardiac sodium-calcium exchanger. Clinical Research 42(1): 19A, 1994

Sodium-calcium exchanger is initially expressed in a heart-restricted pattern within the early mouse embryo. Mechanisms of Development 88(1): 119-122, 1999

Identification and cloning of a truncated isoform of the cardiac sodium-calcium exchanger in the BALB/c mouse heart. Biochemical Genetics 36(3-4): 119-135, 1998

Ischemic tolerance of homozygous transgenic mouse hearts overexpressing the sodium-calcium exchanger. Annals of the new York Academy of Sciences 976: 483-486, 2002

Evidence for the beat dependent activation of the sodium calcium exchanger in heart by intracellular calcium. Biophysical Journal 59(2 Part 2): 244A, 1991

Sodium-calcium exchanger (NCX-1) and calcium modulation: NCX protein expression patterns and regulation of early heart development. Developmental Dynamics: An Official Publication of the American Association of Anatomists 221(3): 249-264, 2001

Regulation of cardiac sodium-calcium exchanger by beta-adrenergic agonists. Proceedings of the National Academy of Sciences of the United States of America 93(11): 5527-5532, 1996

Myocardial gene expression of sodium/calcium exchanger and sarcoplasmic reticulum calcium-ATPase in human heart failure. Circulation 86(4 Suppl 1): I860, 1992

Increased intracellular sodium in heart failure causes reversed mode Na/Ca-exchanger dependent contribution to excitation-contraction coupling and increased fractional sarcoplasmic reticulum calcium release. European Heart Journal 24(Abstract Suppl): 682, 2003

Ryanodine receptor- and sodium-calcium exchanger-mediated spontaneous calcium activity in immature oligodendrocytes in cultures. Neuroscience Letters 732: 134913, 2020

Low flow ischaemia induces sodium-calcium exchanger and sarcoplasmic reticulum calcium ATPase gene expression in senescent rat heart. European Heart Journal 17(ABSTR Suppl ): 567, 1996

Sodium-calcium exchanger overexpression in the heart. Basic Research in Cardiology 97(1 Suppl): I31-I35, 2002