Related Experiment Video

Updated: Aug 17, 2026

Isolation and Cryopreservation of Neonatal Rat Cardiomyocytes
07:05

Isolation and Cryopreservation of Neonatal Rat Cardiomyocytes

Published on: April 9, 2015

Calcium handling by sarcoplasmic reticulum of neonatal swine cardiac myocytes

C M Hohl1, B Livingston, J Hensley

  • 1Department of Medical Biochemistry, Ohio State University, Columbus 43210-1218, USA.

The American Journal of Physiology
|July 1, 1997
PubMed

Insights

Neonatal piglets are a key model for studying heart function. This study characterizes their cardiac sarcoplasmic reticulum (SR), revealing its significant role in excitation-contraction coupling for neonatal piglet myocytes.

Area of Science:

  • Cardiology
  • Physiology
  • Molecular Biology

Background:

  • Neonatal piglets serve as a valuable model for human infant cardiac studies due to physiological similarities.
  • Characterization of the cardiac sarcoplasmic reticulum (SR) in neonatal piglets is crucial for understanding neonatal heart function.

Purpose of the Study:

  • To thoroughly characterize the cardiac sarcoplasmic reticulum (SR) in isolated newborn piglet cardiac ventricular myocytes.
  • To examine Ca2+ pump kinetics, efflux channel characteristics, Ca2+ transients, and contractile movements within these myocytes.

Main Methods:

  • Utilized digitonin-lysed myocytes for measuring oxalate-supported, ATP-dependent 45Ca2+ uptake to assess SR Ca2+ pump kinetics.
  • Employed [3H]ryanodine binding assays to determine characteristics of the SR efflux channel.
  • Recorded electrically stimulated Ca2+ transients (using fura 2) and cell length changes under varying extracellular Ca2+ concentrations.

Main Results:

  • Maximum uptake rate (Vmax) and half-maximal effective concentration (K0.5) for SR Ca2+ uptake were quantified.
  • Phospholamban phosphorylation significantly impacted Vmax and K0.5, indicating its regulatory role.
  • Ryanodine and SR calcium ATPase inhibitor abolished Ca2+ transients, confirming SR involvement.

Conclusions:

  • The cardiac sarcoplasmic reticulum (SR) plays a significant role in excitation-contraction coupling in neonatal piglet myocytes.
  • Understanding SR function in this model is vital for research into neonatal cardiac physiology and disease.

More Related Videos

Measurement of Calcium Fluctuations Within the Sarcoplasmic Reticulum of Cultured Smooth Muscle Cells Using FRET-based Confocal Imaging10:05

Measurement of Calcium Fluctuations Within the Sarcoplasmic Reticulum of Cultured Smooth Muscle Cells Using FRET-based Confocal Imaging

Published on: June 20, 2016

Assessment of Sarcoplasmic Reticulum Calcium Reserve and Intracellular Diastolic Calcium Removal in Isolated Ventricular Cardiomyocytes11:00

Assessment of Sarcoplasmic Reticulum Calcium Reserve and Intracellular Diastolic Calcium Removal in Isolated Ventricular Cardiomyocytes

Published on: September 18, 2017

Related Concept Videos

Feedback Regulation of Calcium Concentration01:27

Feedback Regulation of Calcium Concentration

Calcium is an essential signaling molecule required for various cellular functions. Calcium pumps and ion channels on cell and organellar membranes, such as those on the endoplasmic reticulum (ER), regulate calcium concentrations inside the cell. They remain closed, keeping the cytosolic calcium levels low at a resting state.
Various transmembrane receptors, such as G protein-coupled receptors (GPCRs), elicit a response to extracellular signals by increasing cytosolic calcium. Activated GPCRs...
Relaxation of Skeletal Muscles01:29

Relaxation of Skeletal Muscles

The period of muscle contraction primarily influences the duration of stimulation at the neuromuscular junction (NMJ), the presence of free calcium ions in the sarcoplasm, and the availability of energy or ATP to support contractions.
When an action potential reaches the axon terminal, it depolarizes the membrane and opens voltage-gated sodium channels. Sodium ions enter the cell, further depolarizing the presynaptic membrane. This depolarization causes voltage-gated calcium channels to open.
Structure of Cardiac Muscles01:13

Structure of Cardiac Muscles

Cardiac muscle, or myocardium, is a specialized type of muscle found exclusively in the heart. Its unique structural and functional characteristics enable the heart to perform its vital role of pumping blood throughout the body continuously and rhythmically. The cardiac muscle cells, or cardiomyocytes, possess an endomysium and perimysium but do not have an epimysium.
Compared to skeletal muscles, cardiac muscle cells are small and mostly have a single nucleus. Additionally, they are usually...
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...
Smooth Muscle Contraction01:25

Smooth Muscle Contraction

Smooth muscle contraction is a complex process vital for various bodily functions, from maintaining blood vessel tension to facilitating the movement of food through the digestive tract. Unlike striated muscles, smooth muscle contraction begins more slowly and lasts longer.
The onset of contraction is triggered by an increase in calcium ions within the sarcoplasm, similar to the process in striated muscle. However, smooth muscles have a relatively smaller reservoir of the sarcoplasmic...