We have studied the post-natal maturation of excitation-contraction coupling in rat ventricle by means of pharmacological agents that selectively modulate either Ca entry via voltage-dependent sarcolemmal channels (dihydropyridines) or Ca release from sarcoplasmic reticulum (ryanodine). We have investigated the effects of those agents on cardiac contractility, and we have used them as radioligands to examine the properties of their receptors. Our results show that, after birth, dihydropyridine receptors (i.e. voltage-dependent Ca channels) redistribute to transverse tubules, in close proximity of terminal cisternae of sarcoplasmic reticulum. This redistribution favors the mechanism whereby, in adult ventricle, extracellular Ca entry triggers Ca release from sarcoplasmic reticulum.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
SERCA2 dysfunction accelerates angiotensin II-induced aortic aneurysm and atherosclerosis by induction of oxidative stress in aortic smooth muscle cells.
J Mol Cell Cardiol
January 2025
School of Pharmaceutical Sciences, Chongqing University, Chongqing 401331, China; State Key Laboratory of Frigid Zone Cardiovascular Diseases (SKLFZCD), Harbin Medical University, China; Chongqing Key Laboratory of New Drug Delivery System, Chongqing 400038, China. Electronic address:
Background And Aim: Our previous research indicates that sarcoplasmic/endoplasmic reticulum calcium ATPase 2 (SERCA2) dysfunction facilitates the phenotypic transformation of aortic smooth muscle cells (ASMCs) and intensifies aortic aneurysm through the regulation of calcium-dependent pathways and endoplasmic reticulum stress. Our hypothesis is that additional mechanisms are involved in aortic aneurysm and atherosclerosis induced by SERCA2 dysfunction from the perspective of ASMC phenotypic transformation.
Methods & Results: In SERCA2 dysfunctional mice and their control littermates, ASMCs were isolated to analyze protein expression and cell functions, and angiotensin II was infused into these mice that were backcrossed into LDL receptor deficient background to induce aortic aneurysm and atherosclerosis.
MicroRNA-221 protects myocardial contractility in myocardial ischemia/reperfusion injury through phospholamban.
PLoS One
January 2025
Department of Pathology, 906 Hospital of Joint Logistic Support Force of PLA, Ningbo, Zhejiang, China.
Objective: To investigate the effects and mechanisms of miRNA 221 on myocardial ischemia/reperfusion injury (MIRI) in mice through the regulation of phospholamban (PLB) expression.
Methods: The MIRI mouse model was created and mice were divided into sham, MIRI, MIRI+ 221, and MIRI+ scr groups, with miRNA 221 overexpression induced in the myocardium of MIRI mice by targeted myocardial injection. Quantitative RT-PCR analysis was performed to observe the variation in miRNA 221, PLB, SERCA2, RYR2, NCX1, Cyt C and caspase 3 mRNA levels in myocardium, while Western blot assessed the levels of PLB, p-PLB (Ser16), p-PLB (Thr17), SERCA2, RYR2, NCX1, Cyt C and caspase 3 proteins.
The juxtamembrane sequence of small ankyrin 1 mediates the binding of its cytoplasmic domain to SERCA1 and is required for inhibitory activity.
J Biol Chem
January 2025
Department of Physiology, School of Medicine, University of Maryland Baltimore, Baltimore, MD, 21201, USA. Electronic address:
Sarcoplasmic/endoplasmic reticulum Ca-ATPase1 (SERCA1) is responsible for the clearance of cytosolic Ca in skeletal muscle. Due to its vital importance in regulating Ca homeostasis, the regulation of SERCA1 has been intensively studied. Small ankyrin 1 (sAnk1, Ank1.
View Article and Find Full Text PDFThe Protective Effect of Nimodipine in Schwann Cells Is Related to the Upregulation of LMO4 and SERCA3 Accompanied by the Fine-Tuning of Intracellular Calcium Levels.
Int J Mol Sci
January 2025
Department of Neurosurgery, Medical Faculty, Martin Luther University Halle-Wittenberg, Ernst-Grube-Straße 40, 06120 Halle (Saale), Germany.
Nimodipine is the current gold standard in the treatment of subarachnoid hemorrhage, as it is the only known calcium channel blocker that has been proven to improve neurological outcomes. In addition, nimodipine exhibits neuroprotective properties in vitro under various stress conditions. Furthermore, clinical studies have demonstrated a neuroprotective effect of nimodipine after vestibular schwannoma surgery.
View Article and Find Full Text PDFMechanistic Insights into Melatonin's Antiarrhythmic Effects in Acute Ischemia-Reperfusion-Injured Rabbit Hearts Undergoing Therapeutic Hypothermia.
Int J Mol Sci
January 2025
Division of Cardiology, Department of Internal Medicine, Chang Gung Memorial Hospital, Taoyuan Branch, Taoyuan 33304, Taiwan.
The electrophysiological mechanisms underlying melatonin's actions and the electrophysiological consequences of superimposed therapeutic hypothermia (TH) in preventing cardiac ischemia-reperfusion (IR) injury-induced arrhythmias remain largely unknown. This study aimed to unveil these issues using acute IR-injured hearts. Rabbits were divided into heart failure (HF), HF+melatonin, control, and control+melatonin groups.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!