收缩性
内科学
运动减退
心脏病学
医学
心肌病
心肌细胞
心肌顿抑
病理生理学
惊人的
内分泌学
儿茶酚胺
舒张期
钙
心力衰竭
缺血
血压
作者
Perla Pérez-Treviño,José Sepúlveda-Leal,Julio Altamirano
出处
期刊:Cell Calcium
[Elsevier]
日期:2020-03-01
卷期号:86: 102138-102138
被引量:10
标识
DOI:10.1016/j.ceca.2019.102138
摘要
Stress-induced cardiomyopathy (SIC) results from a profound catecholaminergic surge during strong emotional or physical stress. SIC is characterized by acute left ventricular apex hypokinesia, in the absence of coronary arteries occlusion, and can lead to arrhythmias and acute heart failure. Although, most SIC patients recover, the process could be slow, and recurrence or death may occur. Despite that the SIC common denominator is a large catecholamine discharge, the pathophysiological mechanism is incompletely understood. It is thought that catecholamines have direct cytotoxicity on apical ventricular myocytes (VM), which have the highest β-adrenergic receptors density, and whose overstimulation might cause acute Ca2+ overload and oxidative stress, causing death in some VM and stunning others. Rodents receiving acute isoproterenol (ISO) overdose (OV) mimic SIC development, however, they have not been used to simultaneously assess Ca2+ handling and contractility status in isolated VM, which might explain ventricular hypokinesia. Therefore, treating rats with a single ISO-OV (67 mg/kg body weight), we sought out to characterize, with confocal imaging, Ca2+ and shortening dynamics in Fluo-4-loaded VM, during the early (1–5 days) and late post-acute phases (15 days). We found that ISO-OV VM showed contractile dysfunction; blunted shortening with slower force development and relaxation. These correlated with Ca2+ mishandling; blunted Ca2+ transient, with slower time to peak and SR Ca2+ recovery. SR Ca2+ content was low, nevertheless, diastolic Ca2+ sparks were more frequent, and their duration increased. Contractility and Ca2+ dysfunction aggravated or remained altered over time, explaining slow recovery. We conclude that diminished VM contractility is the main determinant of ISO-OV hypokinesia and is mostly related to Ca2+ mishandling.
科研通智能强力驱动
Strongly Powered by AbleSci AI