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Comparing the impact of an acute exercise bout on plasma amino acid composition, intraerythrocytic Ca2+ handling, and red cell function in athletes and untrained subjects
- Source :
- Cell Calcium
- Publication Year :
- 2016
-
Abstract
- The N-methyl d-aspartate receptors (NMDARs) mediating Ca(2+) uptake upon stimulation with glutamate and glycine were recently discovered in red blood cells (RBC) of healthy humans. Activation of these receptors with agonists triggered transient Ca(2+)-dependent decrease in hemoglobin oxygen affinity in RBC suspension. The aim of this study was to assess the potential physiological relevance of this phenomenon. Two groups formed by either healthy untrained volunteers or endurance athletes were subjected to a stepwise incremental cycling test to exhaustion. Plasma glutamate levels, activity of the NMDARs, and hemoglobin O2 affinity were measured in blood samples obtained before and after the exercise in both groups. Increase in plasma glutamate levels following exercise was observed in both groups. Transient Ca(2+) accumulation in response to the NMDAR stimulation with NMDA and glycine was followed by facilitated Ca(2+) extrusion from the RBC and compensatory decrease in cytosolic Ca(2+) levels. Short-term activation of the receptors triggered a transient decrease in O2 affinity of hemoglobin in both groups. These exercise-induced responses were more pronounced in athletes compared to the untrained subjects. Athletes were initially presented with lower basal intracellular Ca(2+) levels and hemoglobin oxygen affinity compared to non-trained controls. High basal plasma glutamate levels were associated with induction of hemolysis and formation of echinocytes upon stimulation with the receptor agonists. These findings suggest that glutamate release occurring during exhaustive exercise bouts may acutely facilitate O2 liberation from hemoglobin and improve oxygen delivery to the exercising muscle.
- Subjects :
- 0301 basic medicine
Adult
Male
medicine.medical_specialty
Erythrocytes
Physiology
Stimulation
Red blood cells
NMDA receptors
1307 Cell Biology
03 medical and health sciences
chemistry.chemical_compound
Young Adult
Internal medicine
medicine
1312 Molecular Biology
Humans
Amino Acids
Oxygen delivery
Receptor
Molecular Biology
Exercise
Red Cell
Chemistry
Erythrocyte Membrane
Glutamate receptor
Glutathione
Cell Biology
1314 Physiology
10081 Institute of Veterinary Physiology
030104 developmental biology
Endocrinology
Biochemistry
Athletes
10076 Center for Integrative Human Physiology
Glycine
NMDA receptor
570 Life sciences
biology
Female
Calcium
Hemoglobin
Subjects
Details
- ISSN :
- 01434160
- Database :
- OpenAIRE
- Journal :
- Cell Calcium
- Accession number :
- edsair.doi.dedup.....dddca0bfa3139267ccc130b444bd1501
- Full Text :
- https://doi.org/10.1016/j.ceca.2016.05.005