Features of myocardial metabolism of some amino acids and ammonia in patients with coronary artery disease

Abstract

Fractional myocardial extraction/release of glutamate, glutamine, alanine, ammonia, asparagine, glucose and lactate was studied in 12 subjects with normal coronary anatomy (controls) and 28 patients with coronary artery disease (CAD) during rest and atrial pacing. At rest patients with CAD showed an increased myocardial extraction of glutamate, glucose and lactate and an augmented glutamine and alanine release compared with controls. In all CAD patients myocardial ammonia and asparagine release was found at rest, while all controls showed myocardial extraction of these compounds. Myocardial glutamate extraction correlated positively with glucose and lactate extraction, glutamine and alanine release and inversely with ammonia release in CAD patients at rest. In patients with two- and three-vessel disease pacing-induced ischaemia resulted in a pronounced decrease in myocardial glutamate extraction and glutamine release, augmented myocardial production of ammonia and asparagine and a conversion of lactate extraction into lactate release. During pacing myocardial glutamate extraction was related to alanine and glutamine release and correlated inversely with ammonia and lactate release in these patients. The results indicate that glutamate extraction is closely connected with glucose and lactate extraction and ammonia binding via glutamine formation in the hearts of CAD patients and, thus, with the energy supply of ischaemic myocardium. An assessment of myocardial exchange of the nitrogenous compounds we have studied, complimentary to lactate, is a promising biochemical test for the identification of ischaemic heart disease in man.

Nuclear Magnetic Resonance–Based Metabolomics of Human Filtered Serum: A Great White Hope in Appraisal of Chronic Stable Angina and Myocardial Infarction

“…The present study demonstrates an increased lactate level in CAD patients compared to NC, which is consistent with earlier reports (25)(26)(27)(28). The myocardial enrichment pattern is evident for metabolites related to myocardial anaerobic metabolic end product lactate.…”

Metabolite profiling of blood from individuals undergoing planned myocardial infarction reveals early markers of myocardial injury

“…Finally, metabolite changes observed in humans modulated the response to hypoxic injury in vitro, which suggests that these metabolites not only serve as markers, but may also modulate the evolving response to ischemia in vivo. The metabolic, structural, and functional consequences of ischemia and/or reperfusion have been examined in a wide variety of experimental animal models, including regional ischemia after coronary vessel occlusion in dogs (29)(30)(31) and swine (32)(33)(34)(35) as well as in humans with coronary disease (36)(37)(38)(39)(40) or undergoing heart surgery (41-43). However, prior studies have generally assayed relatively limited subsets of metabolites in focused approaches.…”

Extracellular Amino Acids as Markers of Myocardial Ischemia during Cardioplegic Heart Arrest

“…Among those, the myocardium-specific troponin T is released in reversible and irreversible cell damage [4, 5, 6, 7, 8, 9, 10, 11]. Another sensitive, although unspecific set of markers for myocardial damage is free amino acids [12, 13]. Some are released massively in response to decreased oxygen tension [14].…”