Objective: The aim is to compare the activation of ATP-sensitive potassium channels (K(ATP) channels) in intact and metabolically impaired atrial and ventricular myocytes.
Methods: The K(ATP) channel current is measured by whole cell and gramicidin-perforated patch clamp recordings in 164 cultured neonate rat cardiomyocytes.
Results: In whole cell recordings with 84 micromol/l ADP in pipette, spontaneous activity is significantly higher in atrium than ventricle, and EC(50) for the K(ATP) channel opener diazoxide is 0.13 micromol/l (atrium) versus 3.1 micromol/l (ventricle). With an ATP-regenerating system in pipette, EC(50) for diazoxide is 19.7 micromol/l (atrium) versus 54.9 micromol/l (ventricle). In gramicidin-perforated patch recordings, atrial myocytes respond significantly to 100 nmol/l of the mitochondrial protonophore CCCP, while ventricular myocytes do not. EC(50) for diazoxide is 129 micromol/l (atrium) versus >2500 micromol/l (ventricle) for myocytes exposed to CCCP, and 676 versus >2500 micromol/l, respectively, without CCCP.
Conclusions: (1) K(ATP) channels are significantly more sensitive to metabolic inhibition in atrial than ventricular myocytes. (2) Sensitivity of atrium versus ventricle to the channel opener diazoxide increases from 3:1 to > or = 24:1 with ADP or metabolic inhibition. If extended to intact hearts, the results would predict a higher atrial sensitivity to ischemia, and a high sensitivity of the ischemic atrium to K(ATP) channel openers.
Download full-text PDF |
Source |
|---|---|
| http://dx.doi.org/10.1016/s0008-6363(02)00715-0 | DOI Listing |
Publication Analysis
Top Keywords
Similar Publications
WATCHMAN versus LACbes® device for percutaneous left atrial appendage closure: a single-center, propensity-matched study.
BMC Cardiovasc Disord
January 2025
Department of Cardiology, Changhai Hospital, Naval Medical University, No. 168 Changhai Road, Yangpu District, Shanghai, 200433, China.
Background: Different left atrial appendage closure (LAAC) devices have been introduced into the clinical setting. A new dual-seal mechanism LACbes® occluder with isogenous barbs for LAAC has been designed to facilitate easier delivery and improve safety. The purpose of this study is to compare the clinical outcomes of the WATCHMAN with those of the LACbes® device for LAAC.
View Article and Find Full Text PDFOutcomes of Older Adults and Frail Patients Receiving Idecabtagene Vicleucel: A CIBMTR Study.
Blood Adv
December 2024
H. Lee Moffitt Cancer Center, Tampa, Florida, United States.
Idecabtagene vicleucel (ide-cel) is an anti-BCMA CAR-T cell therapy approved for patients with relapsed/refractory multiple myeloma (RRMM) after 2 prior lines of therapy. There is limited data on outcomes of CAR T in older adults and frail patients with RRMM. In this study, we utilized data from the Center for International Blood and Marrow Transplantation Registry to describe the safety and efficacy of ide-cel in these clinically important subgroups.
View Article and Find Full Text PDFExpanding first-line options for depression: Protocol of a pragmatic comparative effectiveness trial of yoga vs. behavioral activation (the COMPARE study).
PLoS One
January 2025
Warren Alpert Medical School of Brown University, Providence, Rhode Island, United States of America.
Depression is a prevalent mental health condition in the United States and a significant cause of morbidity and mortality. The treatment guidelines for depression recommends either psychotherapy, such as behavioral activation (BA), or a second-generation antidepressant as a first-line treatment for adult patients with depression. However, many individuals with depression do not experience improvement from first-line treatments or choose not to engage in them due to stigma, cost, difficulty with access, and/or side effects.
View Article and Find Full Text PDFAnalysis of Orthopaedic Surgery Residency Match Results: 2016 to 2022.
Cureus
December 2024
Orthopaedic Surgery, University of North Carolina at Chapel Hill School of Medicine, Chapel Hill, USA.
: Objective data examining match trends and applicant characteristics are in high demand given the stakes involved with the orthopaedic surgery match. Our study sought to analyse the trends among matched orthopaedic surgery applicants to clarify how medical students can best prepare for and assess their chances of a successful orthopaedic residency match. : We used the publicly available National Residency Matching Program (NRMP) tool to gather characteristics for matched and unmatched orthopaedic surgery applicants from 2016 to 2022 and compare the probability of matching for all applicants versus each subgroup of reported applicant characteristics using risk difference (RD) and two-tailed p-values.
View Article and Find Full Text PDFMeta-Analysis of Pulsed-Field Ablation Versus- High-Power Short-Duration Ablation for Atrial Fibrillation.
Pacing Clin Electrophysiol
January 2025
Department of Pharmacy, First Affiliated Hospital of Fujian Medical University, Fuzhou, China.
Purpose: To optimize the effectiveness and safety of pulmonary vein isolation, pulsed-field ablation (PFA) and high-power short-duration ablation (HPSD) have recently been incorporated into clinical practice. The objective of this study is to conduct a comparative analysis, focusing on the efficacy, safety, and procedural efficiency of PFA and HPSD in the treatment of atrial fibrillation (AF).
Methods: A thorough search was performed across multiple databases to identify trials that compared PFA with HPSD for AF from their inception until July 2024.
Want 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!