Inhibition of the subsidiary pacemaker activity by zatebradine, an If inhibitor, in the anesthetized dog heart

Journal of Cardiovascular Pharmacology
K YamazakiS Chiba

Abstract

To investigate the role of the hyperpolarization-activated current (If) on the subsidiary pacemaker activity of the heart, we studied the effects of an If inhibitor, zatebradine, and a L-type Ca channel inhibitor, verapamil, on the atrioventicular (AV) junctional rhythm and other cardiac responses to stimulation of the left ansa subclavia (LS) in the autonomically decentralized heart of open-chest anesthetized dog. AV junctional rhythm was induced by clamping the sinoatrial (SA) pacemaker region and confirmed by His-bundle electrograms. Zatebradine 0.1 and 0.3 mumol/kg intravenously (i.v.) similarly attenuated both the AV junctional rate and the increase in the junctional rate in response to LS. However, higher doses (1 and 3 mumol/kg i.v.) of zatebradine changed the junctional rhythm to the atrial rhythm in all cases and decreased the atrial rate further but not the increases in the atrial rate in response to LS. On the other hand, verapamil (0.06, 0.2, and 0.6 mumol/kg i.v.) attenuated the increase in the junctional rate induced by LS dose dependently but did not affect the junctional rate itself. After verapamil, zatebradine did not shift the pacemaker site during LS and it further attenuated the positive chronotropic respon...Continue Reading

Citations

Aug 13, 2013·Heart Rhythm : the Official Journal of the Heart Rhythm Society·Richard L VerrierLuiz Belardinelli
Oct 28, 2014·Journal of Cardiovascular Electrophysiology·Richard L VerrierLuiz Belardinelli
Aug 12, 2014·Heart Rhythm : the Official Journal of the Heart Rhythm Society·Richard L VerrierLuiz Belardinelli
Oct 25, 2016·International Journal of Cardiology·Wanwarang WongcharoenArintaya Phrommintikul

❮ Previous
Next ❯

Related Concepts

Trending Feeds

COVID-19

Coronaviruses encompass a large family of viruses that cause the common cold as well as more serious diseases, such as the ongoing outbreak of coronavirus disease 2019 (COVID-19; formally known as 2019-nCoV). Coronaviruses can spread from animals to humans; symptoms include fever, cough, shortness of breath, and breathing difficulties; in more severe cases, infection can lead to death. This feed covers recent research on COVID-19.

Blastomycosis

Blastomycosis fungal infections spread through inhaling Blastomyces dermatitidis spores. Discover the latest research on blastomycosis fungal infections here.

Nuclear Pore Complex in ALS/FTD

Alterations in nucleocytoplasmic transport, controlled by the nuclear pore complex, may be involved in the pathomechanism underlying multiple neurodegenerative diseases including Amyotrophic Lateral Sclerosis and Frontotemporal Dementia. Here is the latest research on the nuclear pore complex in ALS and FTD.

Applications of Molecular Barcoding

The concept of molecular barcoding is that each original DNA or RNA molecule is attached to a unique sequence barcode. Sequence reads having different barcodes represent different original molecules, while sequence reads having the same barcode are results of PCR duplication from one original molecule. Discover the latest research on molecular barcoding here.

Chronic Fatigue Syndrome

Chronic fatigue syndrome is a disease characterized by unexplained disabling fatigue; the pathology of which is incompletely understood. Discover the latest research on chronic fatigue syndrome here.

Evolution of Pluripotency

Pluripotency refers to the ability of a cell to develop into three primary germ cell layers of the embryo. This feed focuses on the mechanisms that underlie the evolution of pluripotency. Here is the latest research.

Position Effect Variegation

Position Effect Variagation occurs when a gene is inactivated due to its positioning near heterochromatic regions within a chromosome. Discover the latest research on Position Effect Variagation here.

STING Receptor Agonists

Stimulator of IFN genes (STING) are a group of transmembrane proteins that are involved in the induction of type I interferon that is important in the innate immune response. The stimulation of STING has been an active area of research in the treatment of cancer and infectious diseases. Here is the latest research on STING receptor agonists.

Microbicide

Microbicides are products that can be applied to vaginal or rectal mucosal surfaces with the goal of preventing, or at least significantly reducing, the transmission of sexually transmitted infections. Here is the latest research on microbicides.