Background And Purpose: Diabetic cardiomyopathy is a complication of diabetes defined as cardiac dysfunction without the involvement of pericardial vessels, hypertension, or cardiac valve disorders. Ranolazine, an antianginal drug, acts through blocking of cardiac late sodium channels and/or inhibiting beta-oxidation of fatty acids. With regard to its mechanism of action, the present work has been carried out to investigate the potential useful effects of ranolazine on the systolic and diastolic dysfunctions in an experimental rat model of diabetic cardiomyopathy. Lidocaine, as a sodium channel blocker, was used to have a clearer image of the involved mechanisms.
Experimental Approach: Diabetes was induced by streptozocin. After 8 weeks, the effects of cumulative concentrations of ranolazine and lidocaine were evaluated on diabetic and normal hearts by the Langendorff method. Finally, the hearts were isolated from the Langendorff system and adenosine three phosphates (ATP) and adenosine diphosphate (ADP) concentrations were measured to assay the metabolic effect of ranolazine.
Findings/results: Ranolazine significantly decreased the velocity of systolic contraction (+dP/dt) and the velocity of diastolic relaxation (-dP/dt) and developed pressure in normal and diabetic rat hearts. However, this negative effect was greater in normal hearts compared to diabetics. Ranolazine (100 μM) decreased the ATP level only in normal hearts and the ATP/ADP ratio decreased significantly ( < 0.05) in both groups. This reduction was more prominent in normal hearts.
Conclusion And Implications: It is concluded that in the isolated rat heart preparation, ranolazine has no benefit on diabetic cardiomyopathy and may even worsen it. It seems that these effects are related to the metabolic effects of ranolazine.
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http://dx.doi.org/10.4103/1735-5362.314825 | DOI Listing |
Naunyn Schmiedebergs Arch Pharmacol
January 2025
Department of Cardiovascular Diseases, Faculty of Medicine, Mashhad University of Medical Sciences, Mashhad, Iran.
The coronary slow flow phenomenon (CSF) causes persistent chest pains that can affect patients' quality of life. We aimed to examine the ranolazine impacts on clinical symptoms in CSF patients. The present randomized, double-blind, placebo-controlled trial consisted of 44 patients with CSF.
View Article and Find Full Text PDFBiosens Bioelectron
March 2025
Department of Biomedical Engineering, Johns Hopkins University, Baltimore, MD, 21205, United States; Department of Medicine, Johns Hopkins University, Baltimore, MD, 21205, United States; Institute for NanoBio Technology, Johns Hopkins University, Baltimore, MD, 21218, United States; Center for Microphysiological Systems, Johns Hopkins University, Baltimore, MD, 21205, United States. Electronic address:
Cardiotoxicity remains a major challenge in drug development, accounting for 45% of medication withdrawals due to cardiac ischemia and arrhythmogenicity. To overcome the limitations of traditional multielectrode array (MEA)-based cardiotoxicity assays, we developed a Nafion-coated NanoMEA platform with decoupled reference electrodes, offering enhanced sensitivity for electrophysiological measurements. The 'Decoupled' configuration significantly reduced polarization resistance (Rp) from 12.
View Article and Find Full Text PDFEuroIntervention
January 2025
National Heart and Lung Institute, Imperial College London, London, United Kingdom.
Background: Microvascular angina (MVA) is an important contributor to morbidity and mortality in patients with non-obstructive coronary artery disease. Despite improvements in its recognition and diagnosis, uncertainty remains around the most effective treatment strategy, and more data are needed.
Aims: We aimed to evaluate the quality of patient selection in treatment studies of MVA and provide a contemporary overview of the evidence base for the treatment of MVA.
CJC Open
December 2024
University of British Columbia, Vancouver, British Columbia, Canada.
Background: Myocardial infarction with no obstructive coronary arteries (MINOCA), and ischemia with no obstructive coronary arteries (INOCA), are female-predominant conditions; clinical trials are lacking to guide medical management for the common underlying vasomotor etiologies. Data on long-term outcomes of (M)INOCA patients following attendance at a women's heart centre (WHC) are lacking.
Methods: Women diagnosed with MINOCA (n = 51) or INOCA (n = 112) were prospectively followed for 3 years at the Leslie Diamond WHC (LDWHC) in Vancouver.
J Physiol Investig
November 2024
Department of Physiology, National Cheng Kung University Medical College, Tainan, Taiwan.
Tomatidine, a major tomato glycoalkaloid, is effective for the prevention of skeletal muscle wasting and enhancing mitophagy. However, its effects on transmembrane ionic currents are not well explored. In this study, we explored the interactions between tomatidine and Na+ current.
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