Maximal exercise and erythrocyte epoxy fatty acids: a lipidomics study

Area of Science:

• Cardiovascular Physiology
• Lipidomics
• Exercise Science

Background:

• Fatty acid metabolites from CYP, LOX, and COX pathways impact cardiovascular function.
• Plasma analysis overlooks erythrocytes, a significant cell mass and potential reservoir for vasoactive lipids.
• Epoxy fatty acids within red blood cells (RBCs) may regulate vascular capacity upon release.

Purpose of the Study:

• To investigate the hypothesis that maximal physical activity alters epoxy fatty acid levels in RBCs.
• To explore the role of RBC lipidomics in the cardiovascular response to exercise.

Main Methods:

• A standardized maximal treadmill exercise test (Bruce protocol) was employed.
• Hemodynamic parameters (blood pressure, heart rate) and maximal workload (METs) were monitored.
• RBC lipidomics were analyzed using liquid chromatography-tandem mass spectrometry (LC-MS/MS) to quantify various lipid mediators.

Main Results:

• Maximal exercise led to increased levels of CYP-derived epoxy-mediators in RBCs, including epoxyoctadecenoic acids (EpOME), epoxyeicosatrienoic acids (EETs), and epoxydocosapentaenoic acids (EDPs).
• These increases correlated with rising heart rate, systolic blood pressure, and plasma lactate.
• No significant changes were observed in diols or metabolites from LOX, COX, and CYP hydroxylase pathways at maximal exercise intensity.

Conclusions:

• Maximal physical activity significantly influences the epoxy fatty acid profile within red blood cells.
• CYP epoxy-metabolites in RBCs are implicated as potential contributors to cardiovascular adjustments during maximal exertion.
• This research underscores the functional relevance of RBC lipid metabolism in exercise physiology.