Drug receptors for the Ca-antagonists nitrendipine and (-)desmethoxyverapamil (D-888) were studied in porcine cardiac sarcolemma. The dihydropyridine (DHP) derivative [3H]nitrendipine binds to a single population of high affinity sites (KD = 0.44 +/- 0.10 nM, Bmax = 2.43 +/- 0.19 pmol/mg; (n = 8), whereas the phenylalkylamine derivative [3H](-)D-888 interacts with high and low affinity sites of KD = 5.1 +/- 1.4 nM and KD = 438 +/- 86 nM (n = 6) in the same membrane preparations. The antagonists tested differ also with respect to their pharmacological efficacy on cultured intact heart myocytes. The EC50 value of the negative chronotropic effect exerted by D-888 corresponds to its high affinity binding component. Nitrendipine exhibit a 200-fold lower pharmacological efficacy, as would be expected from binding data.
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Biomedicines
December 2024
Ludwig Boltzmann Institute for Cardiovascular Research, Center for Biomedical Research and Translational Surgery, Medical University of Vienna, 1090 Vienna, Austria.
Previously, we showed that blood-based polarizing cardioplegia exerted beneficial cardioprotection during hypothermic ischemia; however, these positive effects of blood-based polarizing cardioplegia were reduced during normothermic ischemia compared to blood-based hyperkalemic (depolarizing) cardioplegia. This study compares crystalloid polarizing cardioplegia to crystalloid depolarizing cardioplegia in a normothermic porcine model of cardiopulmonary bypass; Methods: Twelve pigs were randomized to receive either normothermic polarizing ( = 7) or depolarizing ( = 5) crystalloid cardioplegia. After the initiation of cardiopulmonary bypass, normothermic arrest (34 °C, 60 min) was followed by 60 min of on-pump and 90 min of off-pump reperfusion.
View Article and Find Full Text PDFEur J Trauma Emerg Surg
January 2025
Department of Military Traffic Injury Prevention and Control, Daping Hospital, Army Medical University, Chongqing, 400042, China.
Introduction: While there is evidence supporting the use of ultrasound for real-time monitoring of primary blast lung injury (PBLI), uncertainties remain regarding the timely detection of early PBLI and the limited data correlating it with commonly used clinical parameters. Our objective is to develop a functional incapacity model for PBLI that better addresses practical needs and to verify the early diagnostic effectiveness of lung ultrasound in identifying PBLI.
Methods: We selected six healthy male pigs to develop an animal model using a bio-shock tube (BST-I).
J Cardiovasc Electrophysiol
January 2025
Guangdong Cardiovascular Institute, Guangdong Provincial People's Hospital (Guangdong Academy of Medical Sciences), Southern Medical University, Guangzhou, China.
Background: Pulsed field ablation (PFA) is gaining recognition as a nonthermal, tissue-specific technique for the treatment of atrial fibrillation (AF). The preclinical evaluation of the investigated novel PFA system from Insight Medtech Co. Ltd has demonstrated feasibility, safety, and 30-day efficacy for pulmonary vein isolation (PVI) in the swine model.
View Article and Find Full Text PDFJ Cardiovasc Electrophysiol
January 2025
Department of Cardiovascular Medicine, Mayo Clinic, Rochester, Minnesota, USA.
Background: Pulsed-field ablation (PFA) is an innovative non-thermal method for arrhythmia treatment. The efficacy of various PFA configurations in relation to contact force (CF) has not been well-studied in vivo.
Objectives: This study evaluated the effect of CF on acute bipolar PFA lesions in both a vegetal and an in vivo porcine heart model.
Gels
January 2025
Laboratory of Immunotherapy and Tissue Engineering, Department of Cellular and Tissue Biology, Faculty of Medicine, National Autonomous University of Mexico, Av. Universidad 3000, Copilco Universidad, Coyoacán, Ciudad de México 04510, Mexico.
Currently, there are no therapies that prevent the negative myocardial remodeling process that occurs after a heart attack. Injectable hydrogels are a treatment option because they may replace the damaged extracellular matrix and, in addition, can be administered minimally invasively. Reactive oxygen species generated by ischemia-reperfusion damage can limit the therapeutic efficacy of injectable hydrogels.
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