Red blood cell ATP release correlates with red blood cell hemolysis

Author(s):  
Brian S. Ferguson ◽  
Leslie E. Neidert ◽  
Matthew J. Rogatzki ◽  
Keith R. Lohse ◽  
L. Bruce Gladden ◽  
...  

The precise matching of blood flow to skeletal muscle during exercise remains an important area of investigation. Release of adenosine triphosphate (ATP) from red blood cells (RBCs) is postulated to mediate peripheral vascular tone in response to shear stress, hypoxia, and mechanical deformation. We tested the following hypotheses: 1) RBCs of different densities contain different quantities of ATP; 2) hypoxia is a stimulus for ATP release from RBCs; and 3) hypoxic ATP release from RBCs is related to RBC lysis. Human blood was drawn from male and female volunteers (n=11); the RBCs were isolated and washed. A Percoll gradient was used to separate RBCs by cellular density. Density groups were then re-suspended to 4% hematocrit and exposed to normoxia or hypoxia in a tonometer. Equilibrated samples were drawn and centrifuged; paired analyses of ATP (luminescence via a luciferase-catalyzed reaction) and hemolysis (Harboe spectrophotometric absorbance assay) were measured in the supernatant. ATP release was not different among low-density (LD) cells versus middle-density (MD) versus high-density (HD) cells. Similarly, hemoglobin (Hb) release was not different among the RBC subsets. No difference was found for either ATP release or Hb release following matched exposure to normoxic or hypoxic gas. [ATP] and [Hb] for all subsets combined were linearly correlated (r=0.59, p<0.001). With simultaneous probing for Hb and ATP in the supernatant of each sample, we conclude that ATP release from RBCs can be explained by hemolysis and that hypoxia per se does not stimulate either ATP release or Hb release from RBCs.

2007 ◽  
Vol 292 (6) ◽  
pp. H3038-H3042 ◽  
Author(s):  
Michael D. Rozier ◽  
Vincent J. Zata ◽  
Mary L. Ellsworth

Upon exposure to low Po2, the red blood cells of most species, including humans, release increased amounts of ATP that ultimately serves as a regulator of vascular tone matching oxygen supply with demand. In pathological conditions such as malaria and sepsis, a maldistribution of perfusion exists with its severity often correlated with the extent of elevation of serum lactate frequently in the absence of an alteration in pH. We hypothesized that the increased levels of lactate might impair the ability of red blood cells to appropriately respond to conditions of low Po2, thus preventing its important blood flow regulatory role. Using an in vitro system and rabbit red blood cells, we evaluated the capacity of cells incubated with lactate to release increased amounts of ATP in response to acute exposure to low Po2. We found that in the presence of lactate, the red blood cells did not release ATP. However, when sodium dichloroacetate, a drug used clinically to lower blood lactate levels, was added, ATP release was restored to levels that were not different from that of control cells (no lactate), even though intracellular levels of ATP were not. These results support the presence of a distinct flow regulatory pool of ATP within the red blood cell that can be independently regulated, and that lactate interferes with the ATP production within this pool, thereby diminishing the amount of ATP available for release on exposure to low Po2. Therefore, if lactate levels can be reduced, the vascular regulatory capacity of the red blood cell should be restored, thus enabling the appropriate matching of oxygen supply with oxygen demand.


Lab on a Chip ◽  
2021 ◽  
Author(s):  
Wenxiu Zhao ◽  
Haibo Yu ◽  
Yangdong Wen ◽  
Hao Luo ◽  
Boliang Jia ◽  
...  

Counting the number of red blood cells (RBCs) in blood samples is a common clinical diagnostic procedure, but conventional methods are unable to provide the size and other physical properties...


Lab on a Chip ◽  
2021 ◽  
Author(s):  
Yuncheng Man ◽  
Debnath Maji ◽  
Ran An ◽  
Sanjay Ahuja ◽  
Jane A Little ◽  
...  

Alterations in the deformability of red blood cells (RBCs), occurring in hemolytic blood disorders such as sickle cell disease (SCD), contributes to vaso-occlusion and disease pathophysiology. However, there are few...


2016 ◽  
Vol 806 ◽  
pp. 102-128 ◽  
Author(s):  
D. Matsunaga ◽  
Y. Imai ◽  
C. Wagner ◽  
T. Ishikawa

The reorientation phenomenon of a single red blood cell during sedimentation is simulated using the boundary element method. The cell settles downwards due to a density difference between the internal and external fluids, and it changes orientation toward a vertical orientation regardless of Bond number or viscosity ratio. The reorientation phenomenon is explained by a shape asymmetry caused by the gravitational driving force, and the shape asymmetry increases almost linearly with the Bond number. When velocities are normalised by the driving force, settling/drifting velocities are weak functions of the Bond number and the viscosity ratio, while the angular velocity of the reorientation drastically changes with these parameters: the angular velocity is smaller for lower Bond number or higher viscosity ratio. As a consequence, trajectories of the sedimentation are also affected by the angular velocity, and blood cells with slower reorientation travel longer distances in the drifting direction. We also explain the mechanism of the reorientation using an asymmetric dumbbell. From the analysis, we show that the magnitude of the angular velocity is explained by two main factors: the shape asymmetry and the instantaneous orientation angle.


1999 ◽  
Vol 277 (2) ◽  
pp. H508-H514 ◽  
Author(s):  
Charmaine B. S. Henry ◽  
Brian R. Duling

The endothelial cell glycocalyx influences blood flow and presents a selective barrier to movement of macromolecules from plasma to the endothelial surface. In the hamster cremaster microcirculation, FITC-labeled Dextran 70 and larger molecules are excluded from a region extending almost 0.5 μm from the endothelial surface into the lumen. Red blood cells under normal flow conditions are excluded from a region extending even farther into the lumen. Examination of cultured endothelial cells has shown that the glycocalyx contains hyaluronan, a glycosaminoglycan which is known to create matrices with molecular sieving properties. To test the hypothesis that hyaluronan might be involved in establishing the permeation properties of the apical surface glycocalyx in vivo, hamster microvessels in the cremaster muscle were visualized using video microscopy. After infusion of one of several FITC-dextrans (70, 145, 580, and 2,000 kDa) via a femoral cannula, microvessels were observed with bright-field and fluorescence microscopy to obtain estimates of the anatomic diameters and the widths of fluorescent dextran columns and of red blood cell columns (means ± SE). The widths of the red blood cell and dextran exclusion zones were calculated as one-half the difference between the bright-field anatomic diameter and the width of the red blood cell column or dextran column. After 1 h of treatment with active Streptomyces hyaluronidase, there was a significant increase in access of 70- and 145-kDa FITC-dextrans to the space bounded by the apical glycocalyx, but no increase in access of the red blood cells or in the anatomic diameter in capillaries, arterioles, and venules. Hyaluronidase had no effect on access of FITC-Dextrans 580 and 2,000. Infusion of a mixture of hyaluronan and chondroitin sulfate after enzyme treatment reconstituted the glycocalyx, although treatment with either molecule separately had no effect. These results suggest that cell surface hyaluronan plays a role in regulating or establishing permeation of the apical glycocalyx to macromolecules. This finding and our prior observations suggest that hyaluronan and other glycoconjugates are required for assembly of the matrix on the endothelial surface. We hypothesize that hyaluronidase creates a more open matrix, enabling smaller dextran molecules to penetrate deeper into the glycocalyx.


2018 ◽  
Vol 42 (3) ◽  
pp. 151-157 ◽  
Author(s):  
Antony P McNamee ◽  
Kieran Richardson ◽  
Jarod Horobin ◽  
Lennart Kuck ◽  
Michael J Simmonds

Introduction: Accumulating evidence demonstrates that subhaemolytic mechanical stresses, typical of circulatory support, induce physical and biochemical changes to red blood cells. It remains unclear, however, whether cell age affects susceptibility to these mechanical forces. This study thus examined the sensitivity of density-fractionated red blood cells to sublethal mechanical stresses. Methods: Red blood cells were isolated and washed twice, with the least and most dense fractions being obtained following centrifugation (1500 g × 5 min). Red blood cell deformability was determined across an osmotic gradient and a range of shear stresses (0.3–50 Pa). Cell deformability was also quantified before and after 300 s exposure to shear stresses known to decrease (64 Pa) or increase (10 Pa) red blood cell deformability. The time course of accumulated sublethal damage that occurred during exposure to 64 Pa was also examined. Results: Dense red blood cells exhibited decreased capacity to deform when compared with less dense cells. Cellular response to mechanical stimuli was similar in trend for all red blood cells, independent of density; however, the magnitude of impairment in cell deformability was exacerbated in dense cells. Moreover, the rate of impairment in cellular deformability, induced by 64 Pa, was more rapid for dense cells. Relative improvement in red blood cell deformability, due to low-shear conditioning (10 Pa), was consistent for both cell populations. Conclusion: Red blood cell populations respond differently to mechanical stimuli: older (more dense) cells are highly susceptible to sublethal mechanical trauma, while cell age (density) does not appear to alter the magnitude of improved cell deformability following low-shear conditioning.


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