scholarly journals Axial and Nonaxial Migration of Red Blood Cells in a Microtube

Micromachines ◽  
2021 ◽  
Vol 12 (10) ◽  
pp. 1162
Author(s):  
Naoki Takeishi ◽  
Hiroshi Yamashita ◽  
Toshihiro Omori ◽  
Naoto Yokoyama ◽  
Masako Sugihara-Seki

Human red blood cells (RBCs) are subjected to high viscous shear stress, especially during microcirculation, resulting in stable deformed shapes such as parachute or slipper shape. Those unique deformed RBC shapes, accompanied with axial or nonaxial migration, cannot be fully described according to traditional knowledge about lateral movement of deformable spherical particles. Although several experimental and numerical studies have investigated RBC behavior in microchannels with similar diameters as RBCs, the detailed mechanical characteristics of RBC lateral movement—in particular, regarding the relationship between stable deformed shapes, equilibrium radial RBC position, and membrane load—has not yet been fully described. Thus, we numerically investigated the behavior of single RBCs with radii of 4 μm in a circular microchannel with diameters of 15 μm. Flow was assumed to be almost inertialess. The problem was characterized by the capillary number, which is the ratio between fluid viscous force and membrane elastic force. The power (or energy dissipation) associated with membrane deformations was introduced to quantify the state of membrane loads. Simulations were performed with different capillary numbers, viscosity ratios of the internal to external fluids of RBCs, and initial RBC centroid positions. Our numerical results demonstrated that axial or nonaxial migration of RBC depended on the stable deformed RBC shapes, and the equilibrium radial position of the RBC centroid correlated well with energy expenditure associated with membrane deformations.

PLoS ONE ◽  
2010 ◽  
Vol 5 (2) ◽  
pp. e9447 ◽  
Author(s):  
Agnieszka Dyrda ◽  
Urszula Cytlak ◽  
Anna Ciuraszkiewicz ◽  
Agnieszka Lipinska ◽  
Anne Cueff ◽  
...  

1990 ◽  
Vol 265 (27) ◽  
pp. 16035-16038 ◽  
Author(s):  
P Bütikofer ◽  
Z W Lin ◽  
D T Chiu ◽  
B Lubin ◽  
F A Kuypers

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Ratnasekhar Ch ◽  
Guillaume Rey ◽  
Sandipan Ray ◽  
Pawan K. Jha ◽  
Paul C. Driscoll ◽  
...  

AbstractCircadian clocks coordinate mammalian behavior and physiology enabling organisms to anticipate 24-hour cycles. Transcription-translation feedback loops are thought to drive these clocks in most of mammalian cells. However, red blood cells (RBCs), which do not contain a nucleus, and cannot perform transcription or translation, nonetheless exhibit circadian redox rhythms. Here we show human RBCs display circadian regulation of glucose metabolism, which is required to sustain daily redox oscillations. We found daily rhythms of metabolite levels and flux through glycolysis and the pentose phosphate pathway (PPP). We show that inhibition of critical enzymes in either pathway abolished 24-hour rhythms in metabolic flux and redox oscillations, and determined that metabolic oscillations are necessary for redox rhythmicity. Furthermore, metabolic flux rhythms also occur in nucleated cells, and persist when the core transcriptional circadian clockwork is absent in Bmal1 knockouts. Thus, we propose that rhythmic glucose metabolism is an integral process in circadian rhythms.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Diego Sbardella ◽  
Grazia Raffaella Tundo ◽  
Luisa Campagnolo ◽  
Giuseppe Valacchi ◽  
Augusto Orlandi ◽  
...  

An amendment to this paper has been published and can be accessed via a link at the top of the paper.


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