A transmembrane flux of Ca2+ has been demonstrated in many nerve and muscle cells. In cardiac muscle, Ca2+ channels in the sarcolemma transfer sufficient Ca2+ to trigger and partially control tension development. This time- and voltage-dependent Ca2+ current is also important in the development of the pacemaker potential, or diastolic depolarization. In addition, transmitter release from autonomic nerve varicosities in the myocardium exhibits a strong dependence on external calcium concentration [( Ca2+]o). Agents that selectively alter either pre- or postsynaptic Ca2+ channels are therefore of considerable interest. Our results illustrate two distinct effects of Cd2+ in cardiac muscle. Data from conventional electrophysiological recordings from primary pacemaker cells within the rabbit sinoatrial node indicate that Cd2+ (10(-6)-10(-5) M) may selectively inhibit acetylcholine release. Voltage clamp measurements of transmembrane Ca2+ currents in single isolated bullfrog atrial cells show that Cd2+ (10(-4)-10(-3) M) is also a very potent inhibitor of postsynaptic Ca2+ channels; these effects of Cd2+ mimic those seen after [Ca2+]o removal.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Modeling the effects of thin filament near-neighbor cooperative interactions in mammalian myocardium.
J Gen Physiol
March 2025
Department of Animal, Veterinary, and Food Sciences, College of Agricultural and Life Sciences, University of Idaho, Moscow, ID, USA.
The mechanisms underlying cooperative activation and inactivation of myocardial force extend from local, near-neighbor interactions involving troponin-tropomyosin regulatory units (RU) and crossbridges (XB) to more global interactions across the sarcomere. To better understand these mechanisms in the hearts of small and large mammals, we undertook a simplified mathematical approach to assess the contribution of three types of near-neighbor cooperative interactions, i.e.
View Article and Find Full Text PDFCase report: Multisystemic smooth muscle dysfunction syndrome: a rare genetic cause of infantile interstitial lung disease.
Front Pharmacol
January 2025
Respiratory Department II, National Clinical Research Center for Respiratory Diseases, Beijing Children's Hospital, Capital Medical University, National Center for Children's Health, Beijing, China.
Multisystemic smooth muscle dysfunction syndrome (MSMDS) is an autosomal dominant disorder caused by mutations in the gene, resulting in variable clinical manifestation and multi-organ dysfunction. Interstitial lung disease (ILD) is a rare phenotype of this condition. We describe a rare infant case of an 8-month-old boy who presented with progressively worsening dyspnea, along with intermittent episodes of respiratory distress and cyanosis since birth.
View Article and Find Full Text PDFNon-compaction cardiomyopathy and visceral leishmaniasis: uncommon combination with therapeutic challenges in a resource limited-setting.
Sudan J Paediatr
January 2024
Pediatric Department, Faculty of Medicine, National University, Khartoum, Sudan.
Non-compaction cardiomyopathy (NCCM) or spongy myocardium is a rare type of congenital cardiomyopathy. Visceral leishmaniasis is a protozoal disease caused by and transmitted by the bite of female sand-fly species of , which is common in tropical areas like Sudan. We report a 6-year-old female, presented with a fever of unknown origin, weight loss, anemia that necessitated multiple blood transfusions and had hepatosplenomegaly.
View Article and Find Full Text PDFUse of Indocyanine Green (ICG) to Assess Myocardial Perfusion and Territorial Distribution of Vein Grafts Implanted on Coronary Arteries in an Porcine Model. A Potential Adjunct to Assist Revascularization Strategies and Training in Coronary Artery Bypass Grafting.
Rev Cardiovasc Med
January 2025
Cardiac Surgery, University of Cincinnati Medical Center, Cincinnati, OH 45202, USA.
Background: The fluorescent dye indocyanine green (ICG) has been used to identify anatomical structures intraoperatively in coronary artery bypass grafting (CABG). This study aimed to evaluate the feasibility of using ICG to assess graft patency and territorial distribution of myocardial reperfusion during CABG.
Methods: Porcine arrested hearts (n = 18) were used to evaluate territorial distribution of native coronary arteries and of a coronary bypass constructed with porcine saphenous vein graft (SVG) using ICG.
Arrhythmogenic Right Ventricular Cardiomyopathy Presenting With VT Electrical Storm.
J Community Hosp Intern Med Perspect
January 2025
Corewell Health South, Saint Joseph, MI, USA.
Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is a right ventricular disease caused by desmosomal gene mutations leading to fibro-fatty replacement of the myocardium causing ventricular arrhythmias such as ventricular tachycardia (VT). A 59-year-old female presented with new onset VT manifesting as shortness of breath and chest discomfort. Diagnostic workup revealed right ventricular dilation/dysfunction on echocardiogram, VT with left bundle branch block (LBBB) and diffuse T wave inversions (TWIs) on EKG.
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!