Related Experiment Video

Updated: Jul 5, 2026

Analysis of Cardiac Contractile Dysfunction and Ca2+ Transients in Rodent Myocytes
07:32

Analysis of Cardiac Contractile Dysfunction and Ca2+ Transients in Rodent Myocytes

Published on: May 25, 2022

Age-related peculiarities of contractile activity of rat myocardium during blockade of hyperpolarization-activated

T L Zefirov1, A E Gibina, A M Sergejeva

  • 1Department of Anatomy, Physiology, and Human Health Protection, Tatar State Humanitarian-Pedagogical University, Kazan. zefirovtl@mail.ru

Bulletin of Experimental Biology and Medicine
|May 7, 2008
PubMed

Insights

The study investigated how blocking hyperpolarization-activated cation currents affects rat heart muscle contraction. ZD7288 increased contraction in most age groups but decreased it in 3-week-old rats, suggesting age-dependent effects.

Area of Science:

  • Cardiology
  • Physiology
  • Pharmacology

Background:

  • Hyperpolarization-activated cation currents (Ih) play a role in regulating cardiac contractility.
  • The impact of Ih blockade on myocardial contractility across different developmental stages is not fully understood.

Purpose of the Study:

  • To examine the effect of blocking non-selective hyperpolarization-activated cation currents on atrial and ventricular myocardial contractility in rats of various ages.
  • To determine if the effects of Ih blockade on cardiac contractility are age-dependent.

Main Methods:

  • Isolation of atrial and ventricular myocardial strips from rats aged 1, 3, 8, and 20 weeks.
  • Assessment of contractile activity under conditions of blockade of non-selective hyperpolarization-activated cation currents using ZD7288.
  • Comparison of contractile responses across different age groups.

Main Results:

  • ZD7288, a blocker of non-selective hyperpolarization-activated cation currents, increased the contraction force of atrial and ventricular myocardial strips in 1-, 8-, and 20-week-old rats.
  • Conversely, ZD7288 produced an opposite effect, decreasing contractile activity, in atrial and ventricular myocardial strips from 3-week-old rats.
  • These findings indicate a significant age-dependent difference in the response to Ih blockade.

Conclusions:

  • The blockade of non-selective hyperpolarization-activated cation currents has differential effects on cardiac contractility based on the age of the rats.
  • Young rats (3 weeks) exhibit a unique sensitivity to Ih blockade, suggesting developmental changes in the role of these currents in myocardial function.
  • Further research is warranted to elucidate the specific mechanisms underlying these age-dependent responses in cardiac contractility.

More Related Videos

Isolation and Functional Characterization of Human Ventricular Cardiomyocytes from Fresh Surgical Samples14:39

Isolation and Functional Characterization of Human Ventricular Cardiomyocytes from Fresh Surgical Samples

Published on: April 21, 2014

Contractility Measurements on Isolated Papillary Muscles for the Investigation of Cardiac Inotropy in Mice06:22

Contractility Measurements on Isolated Papillary Muscles for the Investigation of Cardiac Inotropy in Mice

Published on: September 17, 2015

Related Concept Videos

Cardiac Action Potential01:30

Cardiac Action Potential

Cardiac action potentials are essential for proper heart function, enabling the rhythmic contractions needed for adequate blood circulation. Nodal cells and Purkinje fibers, specialized for electrical conduction, generate these action potentials.
The cardiac action potential process involves a series of phases characterized by the movement of ions across the cardiac cell membranes, leading to the depolarization and repolarization of the cardiac myocytes.
Ionic Basis of Cardiac Action Potentials
Specialized Characteristics of Cardiac Muscles01:27

Specialized Characteristics of Cardiac Muscles

The primary role of cardiac muscles is to propel blood throughout the cardiovascular system. The cardiac muscle cells, or cardiomyocytes, exhibit specialized characteristics that allow them to perform this function.
Cardiac muscle cells are smaller than skeletal muscles, averaging 10–20 mm in diameter and 50–100 mm in length. However, they have large energy demands for continuous contraction and relaxation. This energy is almost exclusively derived from aerobic metabolism of energy reserves in...