Cardiac creatine kinase metabolite compartments revealed by NMR magnetization transfer spectroscopy and subcellular fractionation.

Biochemistry

Institut National de la Santé et de la Recherche Médicale U-446, Cardiologie Cellulaire et Moléculaire, Université Paris-Sud, Chatenay Malabry, France.

Published: February 2001

In the perfused rat heart NMR inversion transfer revealed the existence of a compartment of ATP not exchanging through creatine kinase (CK), as demonstrated by an apparent discrepancy between the forward (F(f)) and reverse (F(r)) CK flux if this compartment was neglected in the analysis [Joubert et al. (2000) Biophys. J. 79, 1-13]. To localize this compartment, CK fluxes were measured by inversion of PCr (inv-PCr) or gamma ATP (inv-ATP), and the distribution of metabolites between mitochondria and cytosol was studied by subcellular fractionation. Physiological conditions were designed to modify the concentration and distribution of CK metabolites (control, adenylate depletion, inhibition of respiration, KCl arrest). Depending on cardiac activity, mitochondrial ATP (mito-ATP) assessed by fractionation varied from 11% to 30% of total ATP. In addition, the apparent flux discrepancy increased together with mito-ATP (F(f)/F(r) ranged from 0.85 to 0.50 in inv-PCr and from 1.13 to 1.88 in inv-ATP). Under conditions masking the influence of the ATP-P(i) exchange on CK flux, the ATP compartment could be directly quantified by the apparent flux discrepancy; its size was similar to that of mito-ATP measured by fractionation. Thus NMR inversion technique is a potential tool to assess metabolite compartmentation in the whole organ.

Download full-text PDF

Source
http://dx.doi.org/10.1021/bi001695jDOI Listing

Publication Analysis

Top Keywords

creatine kinase
8
subcellular fractionation
8
nmr inversion
8
distribution metabolites
8
apparent flux
8
flux discrepancy
8
atp
5
cardiac creatine
4
kinase metabolite
4
metabolite compartments
4

Similar Publications

Sporadic and Recurrent Exertional Rhabdomyolysis.

Vet Clin North Am Equine Pract

January 2025

Michigan State University, Large Animal Clinical Sciences, College of Veterinary Medicine, East Lansing, MI, USA. Electronic address:

Horses are particularly susceptible to developing exertional rhabdomyolysis (ER) characterized by muscle stiffness, pain, and reluctance to move. Diagnosis requires establishing abnormal increases in serum creatine kinase activity when horses exhibit clinical signs. The 2 main categories of ER include sporadic ER arising from extrinsic causes and chronic ER that arises from intrinsic continuous or episodic abnormalities in muscle function.

View Article and Find Full Text PDF

Objectives: Ischemia/reperfusion (IR)-induced ventricular arrhythmia, which mainly occurs after the opening of coronary artery occlusion, poses a clinical problem. This study aims to investigate the effectiveness of pretreatment with coenzyme Q (CoQ) in combination with mitochondrial transplantation on IR-induced ventricular arrhythmias in aged rats.

Materials And Methods: Myocardial IR induction was performed by left anterior descending coronary artery occlusion for 30 min, followed by re-opening for 24 hr.

View Article and Find Full Text PDF

Intensive care unit-acquired weakness (ICU-AW) is recognized as newly-acquired bilateral muscle weakness, which is a complication of critical illness in the ICU; however, there are no reports on the pathogenesis and early predictors of ICU-AW specifically associated with cardiogenic shock (CS). Therefore, this study aimed to investigate the clinical characteristics of ICU-AW in patients with CS requiring mechanical circulatory support (MCS). This study was a single-center, prospective, and observational study.

View Article and Find Full Text PDF

Hoffmann syndrome, a rare manifestation of hypothyroid myopathy in adults, is characterised by muscle weakness, stiffness and pseudohypertrophy. Here, we report the case of a middle-aged man who presented with progressive weakness in proximal muscles (in the form of difficulty in climbing stairs, rising from a seated position, combing hair and lifting objects) and leg swelling for 6 months. Physical examination revealed pseudohypertrophy of calf muscles with pronounced symmetric weakness in proximal upper and lower limbs.

View Article and Find Full Text PDF

During the harvest of Ilex paraguariensis, approximately 2-5 tons per hectare of thick stems are left on the soil surface. The outer portion of these stems, referred to as the coproduct, constitutes 30% of the total residue mass. Although this coproduct has been partially characterized in terms of its phytochemical profile, its technological applications remain unexplored.

View Article and Find Full Text PDF

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!