Increased Contribution in Heart Failure
نویسندگان
چکیده
Although the downregulation of creatine kinase activity has been associated with heart failure, creatine kinase–deficient transgenic hearts have a preserved contractile function. This suggests the existence of alternative phosphotransfer pathways in the myocardium, the identity of which is still unknown. In this study, we examined the contribution of adenylate kinase–catalyzed phosphotransfer to myocardial energetics. In the isolated mitochondria/ actomyosin system, which possesses endogenous adenylate kinase activity in both compartments, substrates for adenylate kinase promoted the rate and amplitude of actomyosin contraction that was further enhanced by purified adenylate kinase. Inhibition of adenylate kinase activity diminished both actomyosin contraction and mitochondrial respiration, which indicated reduced energy flow between mitochondria and myofibrils. In intact myocardium, the net adenylate kinase–catalyzed phosphotransfer rate was 10% of the total ATP turnover rate as measured by O-phosphoryl labeling in conjunction with gas chromatography and mass spectrometry. In pacing-induced failing heart, adenylate kinase–catalyzed phosphotransfer increased by 134% and contributed 21% to the total ATP turnover. Concomitantly, the contribution by creatine kinase dropped from 89% in normal hearts to 40% in failing hearts. These phosphotransfer changes were associated with reduced levels of metabolically active ATP but maintained overall ATP turnover rate. Thus, this study provides evidence that adenylate kinase facilitates the transfer of high-energy phosphoryls and signal communication between mitochondria and actomyosin in cardiac muscle, with an increased contribution to cellular phosphotransfer in heart failure. This phosphotransfer function renders adenylate kinase an important component for optimal myocardial bioenergetics and a compensatory mechanism in response to impaired intracellular energy flux in the failing heart. (Circ Res. 1999;84:1137-1143.)
منابع مشابه
Endurance training induces fiber type-specific revascularization in hindlimb skeletal muscles of rats with chronic heart failure
Objective(s): Previous studies showed that skeletal muscle microcirculation was reduced in chronic heart failure. The aim of this study was to investigate the effects of endurance training on capillary and arteriolar density of fast and slow twitch muscles in rats with chronic heart failure. Materials and Methods: Four weeks after surgeries (left anterior descending (LAD) artery occlusion), chr...
متن کاملImpact of Aerobic Exercise on Restoration of Soleus and Gastrocnemius Muscles Microcirculations in Wistar Rats with Chronic Heart Failure
ABSTRACT Background and Objective: Scientific evidence reveals that the density of skeletal muscle microcirculations decreases in the patients with chronic heart failure. Therefore, this study aimed to determine the impact of submaximal aerobic exercise training on restoration of fast/slow-twitch muscle fibers microcirculation in rats with myocard...
متن کاملA Review on Adaptation of Heart Failure Patients Based on Roy adaptation model: A Review Study
Introduction: Diseases of heart failure are considered as one of the main challenges of health care systems. One of the main components of care models in heart failure is patient involvement. In this regard, the adaptation model (RAM) is one of the most popular and most widely used nursing patterns that specifically address compatibility issues. The purpose of this article is to review the adap...
متن کاملThe cardioprotective effects of 4-O-(2″-O-acetyl-6″-O- p-coumaroyl-β-D-glucopyranosyl)-p-coumaric acid (4-ACGC) on chronic heart failure
The 4-ACGC isolated from BP was prepared to investigate the cardioprotective effects on attenuating chronic heart failure in vivo and in vitro. A chronic heart failure (CHF) rat model was established to investigate the cardioprotective effects of 4-ACGC. From this, several cardiac function indexes were recorded. The inflammatory markers including tumor necrosis factor-α (TNF-α), Interleukin-6 (...
متن کاملBackground & Objective : Heart failure is a clinical syndrome and increases in rate by aging. Because changes in ECG and electrolytes are variable, specific and sometimes independent to the disease with different methods to be diagnosed, in this study we tried to find a way to diagnose them. Materials & Methods: This is a retrospective descriptive-analytic study. Data was collected from dec...
متن کاملPrognostic Value of Soluble ST2 (sST2) Serum Levels in Infants and Children with Heart Failure Complicating Congenital Heart Disease
Background Heart failure (HF) in infants and children with congenital heart disease (CHD) is a crucial complication with different outcomes. Many biomarkers are used as prognostic indicators. Soluble ST2 (sST2) is one of these markers studied in adults with HF. We aimed to study the prognostic value of sST2 in CHD children with HF. Materials and Methods In current case-control study, thirty-six...
متن کامل