The properties of several components of outward K(+) currents, including the pharmacological and kinetics profiles as well as the respective molecular correlates, have been identified in mouse cardiac myocytes. Surprisingly little is known with regard to the Ca(2+)-activated ionic currents. We studied the Ca(2+)-activated transient outward currents in mouse ventricular myocytes. We have identified a 4-aminopyridine (4-AP)- and tetraethyl ammonium-resistant transient outward current that is Ca(2+) dependent. The current is carried by Cl(-) and is critically dependent on Ca(2+) influx via voltage-gated Ca(2+) channels and the sarcoplasmic reticulum Ca(2+) store. The current can be blocked by the anion transport blockers niflumic acid and 4,4'-diisothiocyanatostilbene-2,2'-disulfonic acid. Single channel recordings reveal small conductance channels (approximately 1 pS in 140 mM Cl(-)) that can be blocked by anion transport blockers. Ensemble-averaged current faithfully mirrors the transient kinetics observed at the whole level. Niflumic acid (in the presence of 4-AP) leads to prolongation of the early repolarization. Thus this current may contribute to early repolarization of action potentials in mouse ventricular myocytes.
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http://dx.doi.org/10.1152/ajpheart.00044.2002 | DOI Listing |
FASEB J
January 2025
Key Laboratory of Birth Defects and Related Diseases of Women and Children of MOE, Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan, China.
Congenital heart disease (CHD) represents a major birth defect associated with substantial morbidity and mortality. Although environmental factors are acknowledged as potential contributors to CHD, the underlying mechanisms remain poorly understood. Bisphenol A (BPA), a common endocrine disruptor, has attracted significant attention due to its widespread use and associated health risks.
View Article and Find Full Text PDFBioengineering (Basel)
December 2024
Fusion Oriented Research for Disruptive Science and Technology, Japan Science and Technology Agency, 5-3, Yonbancho, Chiyoda-ku, Tokyo 102-8666, Japan.
Mechanical forces influence cellular proliferation, differentiation, tissue morphogenesis, and functional expression within the body. To comprehend the impact of these forces on living organisms, their quantification is essential. This study introduces a novel microdifferential pressure measurement device tailored for cellular-scale pressure assessments.
View Article and Find Full Text PDFHum Gene Ther
January 2025
Department of Internal Medicine V, University Hospital Schleswig-Holstein and University of Kiel, Kiel, Germany.
Adeno-associated viral (AAV) vectors are increasingly used for preclinical and clinical cardiac gene therapy approaches. However, gene transfer to cardiomyocytes poses a challenge due to differences between AAV serotypes in terms of expression efficiency and . For example, AAV9 vectors work well in rodent heart muscle cells but not in cultivated neonatal rat ventricular cardiomyocytes (NRVCMs), necessitating the use of AAV6 vectors for studies.
View Article and Find Full Text PDFJ Transl Med
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Department of Oncology, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.
Background: Vascular endothelial growth factor (VEGF) and VEGF receptor (VEGFR) inhibitors play a pivotal role in treating various tumors; however, the clinical characteristics and molecular mechanisms of their associated heart failure (HF) remain incompletely understood.
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Arterioscler Thromb Vasc Biol
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Metabolic and Immune Diseases Department, Biomedical Research Institute Sols-Morreale (IIBM), National Research Council (CSIC), Autonoma University of Madrid, Spain (T.A.-G., S.M.-T., R.C.-M., S.U.-B., S.M.-P.).
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