Jove
Visualize
Contact Us
JoVE
x logofacebook logolinkedin logoyoutube logo
ABOUT JoVE
OverviewLeadershipBlogJoVE Help Center
AUTHORS
Publishing ProcessEditorial BoardScope & PoliciesPeer ReviewFAQSubmit
LIBRARIANS
TestimonialsSubscriptionsAccessResourcesLibrary Advisory BoardFAQ
RESEARCH
JoVE JournalMethods CollectionsJoVE Encyclopedia of ExperimentsArchive
EDUCATION
JoVE CoreJoVE BusinessJoVE Science EducationJoVE Lab ManualFaculty Resource CenterFaculty Site
Terms & Conditions of Use
Privacy Policy
Policies

Related Concept Videos

Synthesis and Regulation of Thyroid Hormones01:20

Synthesis and Regulation of Thyroid Hormones

9.0K
Low blood levels of the thyroid hormones — triiodothyronine (T3) and thyroxine (T4) — signal the hypothalamus to release the thyrotropin-releasing hormone (TRH). TRH then reaches the pituitary gland and stimulates the release of thyroid-stimulating hormone(TSH) into the bloodstream.
Upon reaching the thyroid gland, TSH stimulates the follicular cells' active uptake of iodide ions from the blood. The ions diffuse to the apical surface of the cells and are oxidized to iodine. The...
9.0K
Functions of Thyroid Hormones01:18

Functions of Thyroid Hormones

6.7K
The thyroid hormone (TH) plays a pivotal role in the intricate orchestration of physiological processes, exerting profound effects on development, metabolism, and homeostasis throughout different life stages.
TH is indispensable for the normal development and maturation of the skeletal, muscular, and nervous systems during fetal and childhood growth. It facilitates bone mineral turnover and regulates protein synthesis in developing tissues, contributing significantly to overall growth and...
6.7K
Pathophysiology of Cardiac Performance01:29

Pathophysiology of Cardiac Performance

2.0K
Typical heart performance is influenced by heart rate, rhythm, myocardial contraction, and metabolism or blood flow. The cardiac muscle exhibits distinct electrophysiological features, including pacemaker activity and calcium channel control, which play a vital role in the heart's response to various drugs. The autonomic nervous system, comprising the sympathetic and parasympathetic branches, regulates heart rate. Sympathetic activation increases heart rate, while parasympathetic activation...
2.0K
Heart Failure Drugs: Inotropic Agents01:26

Heart Failure Drugs: Inotropic Agents

1.9K
Positive inotropic agents are commonly used as the first line of treatment for heart failure. One such agent is digoxin, derived from the genus Digitalis, which has been known for centuries but effectively utilized since 1785. However, these cardiac glycosides can have potentially toxic effects due to their mechanism of action, which involves inhibiting Na+/K+-ATPase and increasing contractility. Digoxin is absorbed orally and distributed in various tissues, including the CNS. It has a long...
1.9K
Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers01:12

Antiarrhythmic Drugs: Class III Agents as Potassium Channel Blockers

2.9K
Class III antiarrhythmic drugs are a group of medications that can prolong action potentials in the heart. They achieve this by blocking potassium channels or enhancing inward currents from sodium channels. However, these drugs have a unique property of "reverse use-dependence," which is most pronounced at slower heart rates and can lead to torsades de pointes—a specific type of arrhythmia. However, it is essential to note that excessive QT interval prolongation—a measure of...
2.9K
Mechanism of Cardiac Arrhythmias01:28

Mechanism of Cardiac Arrhythmias

2.6K
Arrhythmias are irregular heart rhythms occurring when the heart's electrical impulses become abnormal. These disturbances can lead to various symptoms, depending on their severity and the underlying cause. Some common factors contributing to arrhythmias include hypoxia, ischemia, electrolyte imbalances, excessive catecholamine exposure, drug toxicity, and muscle overstretching. Arrhythmias can be classified into two main types based on the rate and site of origin of abnormal heart rhythms.
2.6K

You might also read

Related Articles

Articles linked to this work by shared authors, journal, and citation graph.

Sort by
Same author

Assessment of environmental radioactivity in the City of Melilla.

Scientific reports·2026
Same author

Indoor radon risk mapping of the Canary Islands using a methodology for volcanic islands combining geological information and terrestrial gamma radiation data.

The Science of the total environment·2024
Same author

Multiparametric analysis for the determination of radon potential areas in buildings on different soils of volcanic origin.

The Science of the total environment·2023
Same author

Correction to: Bacterial etiology of community-acquired pneumonia in immunocompetent hospitalized patients and appropriateness of empirical treatment recommendations: an international point-prevalence study.

European journal of clinical microbiology & infectious diseases : official publication of the European Society of Clinical Microbiology·2021
Same author

Methodology for determination of radon prone areas combining the definition of a representative building enclosure and measurements of terrestrial gamma radiation.

The Science of the total environment·2021
Same author

Frequency, profile, and outcomes of patients with acute heart failure transferred directly to home hospitalization from emergency departments.

Revista clinica espanola·2021

Related Experiment Video

Updated: Mar 31, 2026

Evaluation of Cardiac Contractility Modulation Therapy in 2D Human Stem Cell-Derived Cardiomyocytes
08:47

Evaluation of Cardiac Contractility Modulation Therapy in 2D Human Stem Cell-Derived Cardiomyocytes

Published on: December 16, 2022

2.9K

Thyroid stimulating hormone directly modulates cardiac electrical activity.

H Alonso1, J Fernández-Ruocco2, M Gallego1

  • 1Departamento de Fisiología, Facultad de Farmacia, Universidad del País Vasco UPV/EHU, Vitoria, Spain.

Journal of Molecular and Cellular Cardiology
|October 27, 2015
PubMed
Summary
This summary is machine-generated.

Thyroid-stimulating hormone (TSH) directly alters heart electrical properties. Elevated TSH reduces key potassium currents (Ito and IK1), contributing to cardiac repolarization abnormalities in hypothyroidism.

Keywords:
Calcium channelsCardiac electrophysiologyHypothyroidismPotassium channelsTSHThyrotropin

More Related Videos

Simultaneous Electrical and Mechanical Stimulation to Enhance Cells' Cardiomyogenic Potential
07:41

Simultaneous Electrical and Mechanical Stimulation to Enhance Cells' Cardiomyogenic Potential

Published on: January 18, 2019

8.2K
Advanced Cardiac Rhythm Management by Applying Optogenetic Multi-Site Photostimulation in Murine Hearts
08:43

Advanced Cardiac Rhythm Management by Applying Optogenetic Multi-Site Photostimulation in Murine Hearts

Published on: August 26, 2021

3.0K

Related Experiment Videos

Last Updated: Mar 31, 2026

Evaluation of Cardiac Contractility Modulation Therapy in 2D Human Stem Cell-Derived Cardiomyocytes
08:47

Evaluation of Cardiac Contractility Modulation Therapy in 2D Human Stem Cell-Derived Cardiomyocytes

Published on: December 16, 2022

2.9K
Simultaneous Electrical and Mechanical Stimulation to Enhance Cells' Cardiomyogenic Potential
07:41

Simultaneous Electrical and Mechanical Stimulation to Enhance Cells' Cardiomyogenic Potential

Published on: January 18, 2019

8.2K
Advanced Cardiac Rhythm Management by Applying Optogenetic Multi-Site Photostimulation in Murine Hearts
08:43

Advanced Cardiac Rhythm Management by Applying Optogenetic Multi-Site Photostimulation in Murine Hearts

Published on: August 26, 2021

3.0K

Area of Science:

  • Cardiology
  • Endocrinology
  • Molecular Biology

Background:

  • Hypothyroidism causes cardiac repolarization abnormalities, linked to altered ion currents.
  • The role of thyroid hormones (T3, T4) versus TSH in these changes is debated.
  • Elevated TSH levels correlate with repolarization issues in hypothyroid patients.

Purpose of the Study:

  • To investigate the direct impact of TSH on cardiac electrical properties.
  • To determine if TSH affects specific ion currents involved in cardiac repolarization.

Main Methods:

  • Action potential and ion channel mRNA expression recorded from adult rat left ventricles.
  • Patch-clamp technique used to record repolarizing K(+) currents and L-type Ca(2+) current (ICa-L) in isolated ventricular myocytes.
  • Experimental exposure to TSH.

Main Results:

  • TSH exposure prolonged action potential duration and slightly depolarized resting membrane potential.
  • TSH activation reduced the amplitude of Ito and IK1 currents, linked to decreased channel expression.
  • TSH did not affect ICa-L, IK, or IKur.

Conclusions:

  • TSH directly impacts cardiac electrical activity by reducing Ito and IK1 currents.
  • These TSH-induced changes may explain some cardiac repolarization disturbances observed in hypothyroidism.
  • The findings suggest elevated TSH, not just low T3, contributes to cardiac issues in hypothyroidism.