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Rheological features of erythrocytes in acute myocardial infarction
M G Tozzi-Ciancarelli1, C Di Massimo, A Mascioli
1Department of Biomedical Sciences and Technology and Biometry, University of L'Aquila, Italy.
Insights
Myocardial infarction patients exhibit reduced erythrocyte filtration and increased blood viscosity. Erythrocyte membrane changes, not lipid peroxidation, likely cause these rheological alterations.
Area of Science:
- Cardiovascular Science
- Biophysics
- Hematology
Background:
- Oxidative stress is implicated in acute myocardial infarction (AMI).
- Altered blood rheology, including erythrocyte deformability and aggregation, may contribute to AMI.
- Changes in erythrocyte membrane properties are hypothesized to affect blood flow.
Purpose of the Study:
- To investigate erythrocyte rheological behavior and membrane properties in patients with myocardial infarction.
- To determine the relationship between blood viscosity, erythrocyte filtration, and erythrocyte membrane microviscosity in AMI patients.
Main Methods:
- Measured blood viscosity, plasma viscosity, and erythrocyte filtration in AMI patients.
- Assessed erythrocyte membrane microviscosity using fluorescence polarization.
- Analyzed lipid peroxidation in erythrocyte membranes.
Main Results:
- AMI patients showed decreased erythrocyte filtration and increased blood viscosity, with unchanged plasma viscosity.
- Erythrocyte membrane microviscosity analysis revealed increased rigidity at the lipid/protein boundary and increased fluidity in the deep lipid core.
- No significant changes in membrane protein dynamics or evidence of lipid peroxidation were found.
Conclusions:
- Physico-chemical alterations in the erythrocyte membrane, specifically increased rigidity and fluidity, may underlie the observed decreased erythrocyte filtration in myocardial infarction.
- These membrane perturbations, rather than lipid peroxidation, are likely contributors to the rheological changes observed in AMI patients.
Abstract:
There is evidence that oxidative insult plays a role in the development of acute myocardial infarction. Significance has also been attributed to changes in viscosity of the blood and in the deformability and aggregation of erythrocytes affecting their rheological behavior. In a group of patients with myocardial infarction we found a decreased erythrocyte filtration and an increased blood viscosity with no significant change in plasma viscosity. These changes were accompanied by alterations in the microviscosity of the erythrocyte membrane assessed by measuring the polarization of specific fluorescent molecules. From our data it is evident that there is an increase in the rigidity of the membrane at the lipid/protein boundary, with an associated increase in the fluidity of the deep lipid core of the membrane, while no changes were observed in the dynamic behavior of the membrane proteins. These physico-chemical perturbations in the membrane could be the basis for the decreased filtration of erythrocytes. We found, however, no evidence of lipid peroxidation in the erythrocyte membrane.