scholarly journals Red cell rheology in stomatocyte-echinocyte transformation: roles of cell geometry and cell shape

Blood ◽  
1986 ◽  
Vol 67 (4) ◽  
pp. 1110-1118 ◽  
Author(s):  
WH Reinhart ◽  
S Chien
Keyword(s):  
Cell Volume ◽  
Surface Area ◽  
Optimum Shape ◽  
Red Cell ◽  
Drug Induced ◽  
Filtration Resistance ◽  
Shear Rates ◽  
Geometric Factors ◽  
Shape Changes

Abstract The influence of the shape of the red blood cell during stomatocyte- echinocyte transformation on its deformability was studied by microsieving through pores with diameters of 2.6, 4.5, and 6.9 micron. A stomatocytic transformation was produced by chlorpromazine (0.02, 0.1, and 0.5 mmol/L) and an echinocytic transformation by sodium salicylate (7.5, 30, and 120 mmol/L). For spherostomatocytes, an increase in filtration resistance through 2.6 and 4.5 micron pores was observed, whereas for spheroechinocytes, a decrease in filtration resistance through 2.6 micron pores was found. Larger pores (6.9 micron) were not sensitive to those shape changes. The changes in deformability can be explained by the fact that the surface area of (sphero)-stomatocytes decreased, whereas that of (sphero)-echinocytes increased; the cell volume remained essentially constant. Echinocytes produced by 24-hour adenosine triphosphate depletion differed from drug- induced echinocytes: they had an increased cell volume at constant surface area and consequently an increased filtration resistance through 2.6- and 4.5-micron filter pores. Shape changes with spicule formation are therefore not a homogeneous entity, and cell geometric factors (eg, surface area and volume) must be assessed with care. The viscosity of red cell suspensions at a hematocrit level of 45% was higher for drug-induced echinocytes than discocytes or stomatocytes at all shear rates tested. We conclude that the normal discocyte represents an optimum shape for the flow in vivo since a stomatocytic transformation could impair the passage through the microcirculation (decrease in cell filterability) and an echinocytic transformation could impair the flow in larger vessels (increase in blood viscosity).

scholarly journals Red cell rheology in stomatocyte-echinocyte transformation: roles of cell geometry and cell shape

Blood ◽  
1986 ◽  
Vol 67 (4) ◽  
pp. 1110-1118
Author(s):  
WH Reinhart ◽  
S Chien
Keyword(s):  
Cell Volume ◽  
Surface Area ◽  
Optimum Shape ◽  
Red Cell ◽  
Drug Induced ◽  
Filtration Resistance ◽  
Shear Rates ◽  
Geometric Factors ◽  
Shape Changes

The influence of the shape of the red blood cell during stomatocyte- echinocyte transformation on its deformability was studied by microsieving through pores with diameters of 2.6, 4.5, and 6.9 micron. A stomatocytic transformation was produced by chlorpromazine (0.02, 0.1, and 0.5 mmol/L) and an echinocytic transformation by sodium salicylate (7.5, 30, and 120 mmol/L). For spherostomatocytes, an increase in filtration resistance through 2.6 and 4.5 micron pores was observed, whereas for spheroechinocytes, a decrease in filtration resistance through 2.6 micron pores was found. Larger pores (6.9 micron) were not sensitive to those shape changes. The changes in deformability can be explained by the fact that the surface area of (sphero)-stomatocytes decreased, whereas that of (sphero)-echinocytes increased; the cell volume remained essentially constant. Echinocytes produced by 24-hour adenosine triphosphate depletion differed from drug- induced echinocytes: they had an increased cell volume at constant surface area and consequently an increased filtration resistance through 2.6- and 4.5-micron filter pores. Shape changes with spicule formation are therefore not a homogeneous entity, and cell geometric factors (eg, surface area and volume) must be assessed with care. The viscosity of red cell suspensions at a hematocrit level of 45% was higher for drug-induced echinocytes than discocytes or stomatocytes at all shear rates tested. We conclude that the normal discocyte represents an optimum shape for the flow in vivo since a stomatocytic transformation could impair the passage through the microcirculation (decrease in cell filterability) and an echinocytic transformation could impair the flow in larger vessels (increase in blood viscosity).

Body composition in vivo. VII. Relation between red cell volume and total body water in ewes

1965 ◽  
Vol 16 (4) ◽  
pp. 661 ◽  
Author(s):  
BA Panaretto ◽  
DA Little
Keyword(s):  
Body Composition ◽  
Cell Volume ◽  
Total Body Water ◽  
Mean Value ◽  
Body Water ◽  
Red Cell ◽  
Red Cell Volume ◽  
Total Body ◽  
Body Parameters

The relationship between total body water and red cell volume was determined in a group of non-pregnant crossbred ewes, in an endeavour to obtain a method which did not necessitate the use of radioisotopes for determining body composition. Total body water could be predicted from red cell volume. The 95% confidence interval for a mean value for total body water, predicted from the red cell volume, was ±18.8% of the mean. All other relations which can be derived between the red cell volume and other body parameters depended on this relation. The calculation of body composition from measurements of the red cell volume is discussed.

Effect of changes in the red cell volume on the carbon dioxide titration curve in vivo in the rat

1981 ◽  
Vol 59 (5) ◽  
pp. 500-503
Author(s):  
S. Kaufman ◽  
C. T. Kappagoda
Keyword(s):  
Carbon Dioxide ◽  
Cell Volume ◽  
Titration Curve ◽  
The Body ◽  
Red Cell ◽  
Red Cell Volume ◽  
Titration Curves

Acute in vivo CO2 titration curves were performed on rats anaesthetized with pentobarbitone. The slope of the in vivo CO2 titration curve in the rat was found to be similar to that previously reported in the dog and in man. Removal of approximately 30% of the haemoglobin of the body did not influence significantly the slope of the in vivo CO2 titration curve in the rat.

Effects of leukotrienes on isolated rat glomeruli and cultured mesangial cells

1986 ◽  
Vol 250 (5) ◽  
pp. F838-F844
Author(s):  
R. Barnett ◽  
P. Goldwasser ◽  
L. A. Scharschmidt ◽  
D. Schlondorff
Keyword(s):  
Surface Area ◽  
Mesangial Cells ◽  
Shape Change ◽  
Ang Ii ◽  
Planar Surface ◽  
Glomerular Function ◽  
Shape Changes ◽  
Isolated Rat

Several vasoactive substances influence glomerular function in vivo and alter glomerular surface area and prostaglandin (PG) synthesis in vitro. Leukotrienes (LT) LTC4 and LTD4 may also influence glomerular function in vivo and in the isolated perfused kidney. We therefore compared the effects of LT with those of angiotensin II (ANG II), arginine vasopressin (AVP), and platelet activating factor (PAF) on planar surface area of isolated rat glomeruli and the shape change of cultured mesangial cells and their PG synthesis. ANG II, AVP, and PAF decreased the surface area of isolated rat glomeruli by 10-14% with comparable changes induced by LTC4 and LTD4. Half-maximal effects of LTs were observed at approximately 10(-7) M. Incubation of cultured rat mesangial cells with LTC4 or LTD4 at 10(-7) and 10(-8) M was also associated with shape changes of the cells resulting in significant reductions in planar surface area in a dose- and time-dependent fashion similar to that noted previously with other vasoactive agents. In cells grown on a flexible silicone rubber support, LTD4 resulted in rapid increases in wrinkling of the mobile surface indicating that the shape change may represent cell contraction. The LT-mediated decrease in surface area of glomeruli and mesangial cells was partially antagonized by the LT inhibitor FPL-55712. In contrast to the 11- and 7-fold enhancement of PGE2 synthesis in cultured mesangial cells by ANG II or PAF, neither LTC4 nor LTD4 affected PGE2 production. These results demonstrate that LTC4 and LTD4 cause mesangial shape changes that in the whole glomerulus may decrease glomerular surface area.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals The water channel aquaporin-1 partitions into exosomes during reticulocyte maturation: implication for the regulation of cell volume

Blood ◽  
2009 ◽  
Vol 114 (18) ◽  
pp. 3928-3934 ◽  
Author(s):  
Lionel Blanc ◽  
Jing Liu ◽  
Michel Vidal ◽  
Joel Anne Chasis ◽  
Xiuli An ◽  
...  
Keyword(s):  
Cell Volume ◽  
In Vitro Maturation ◽  
Environmental Changes ◽  
Water Channel ◽  
Red Cell ◽  
Aquaporin 1 ◽  
Reticulocyte Maturation ◽  
Total Pool

Abstract Aquaporin-1 (AQP-1), the universal water channel, is responsible for rapid response of cell volume to changes in plasma tonicity. In the membrane of the red cell the concentration of the protein is tightly controlled. Here, we show that AQP-1 is partially lost during in vitro maturation of mouse reticulocytes and that it is associated with exosomes, released throughout this process. AQP-1 in young reticulocytes localizes to the plasma membrane and also in endosomal compartments and exosomes, formed both in vitro and in vivo. During maturation a part of the total pool of AQP-1 is differentially sorted and released via the exosomal pathway. A proteasome inhibitor, MG132, suppresses secretion of AQP-1, implying that ubiquitination is a sorting signal for its release. We further show that modulation of medium tonicity in vitro regulates the secretion of AQP-1, thus showing that extracellular osmotic conditions can drive sorting of selected proteins by the exosomal pathway. These results lead us to suggest that AQP-1 sorting into exosomes may be the mechanism by which the reticulocyte adapts to environmental changes during its maturation.

scholarly journals Physical Properties of Red Cells as Related to Effects in Vivo. II. Effect of Thermal Treatment on Rigidity of Red Cells, Stroma and the Sickle Cell

Blood ◽  
1968 ◽  
Vol 32 (6) ◽  
pp. 862-871 ◽  
Author(s):  
THOMAS HALE HAM ◽  
RICHARD W. SAYRE ◽  
REBECCA F. DUNN ◽  
JOHN R. MURPHY
Keyword(s):  
Thermal Treatment ◽  
Sickle Cell ◽  
Osmotic Fragility ◽  
Red Cells ◽  
Red Cell ◽  
Sickle Cells ◽  
Sonic Treatment ◽  
Physiologic Saline ◽  
Shape Changes

Abstract Heating of human or dog red cells at 49 C. for 15 minutes or 60 minutes increased resistance to packing by a centrifugal force, increased viscosity and deformed them. After 15 minutes of heating, osmotic fragility was usually normal but was elevated after 60 minutes with the formation of spheroidal cells. The increase in viscosity caused by heating red cells at 49 C. for 60 minutes did not appear to result from the effect of heat on the hemoglobin or the hemolysis products of red cells disrupted by sonic treatment. The heating of intact human or dog red cell stroma in serum, or stroma washed multiple times in physiologic saline however, regularly increased their viscosity and produced buds and microstroma. The rigidity of stroma was increased by heating, probably accounting for the increased viscosity of heated intact red cells. The rigidity of heated stroma of red cells was further demonstrated by showing that the shape changes of the sickling process could be prevented in large part by the heating of sickle cells. Heating did not, however, prevent tactoid formation in stroma-free sickle-cell hemoglobin solutions.

Effects of NO-Donors on Thrombus Formation and Microcirculation in Cerebral Vessels of the Rat

1996 ◽  
Vol 76 (01) ◽  
pp. 111-117 ◽  
Author(s):  
Yasuto Sasaki ◽  
Junji Seki ◽  
John C Giddings ◽  
Junichiro Yamamoto
Keyword(s):  
Blood Flow ◽  
Thrombus Formation ◽  
Dependent Manner ◽  
Red Cell ◽  
Cell Velocity ◽  
Red Cell Velocity ◽  
The Mean ◽  
Wall Shear ◽  
Dose Dependent

SummarySodium nitroprusside (SNP) and 3-morpholinosydnonimine (SIN-1), are known to liberate nitric oxide (NO). In this study the effects of SNP and SIN-1 on thrombus formation in rat cerebral arterioles and venules in vivo were assessed using a helium-neon (He-Ne) laser. SNP infused at doses from 10 Μg/kg/h significantly inhibited thrombus formation in a dose dependent manner. This inhibition of thrombus formation was suppressed by methylene blue. SIN-1 at a dose of 100 Μg/kg/h also demonstrated a significant antithrombotic effect. Moreover, treatment with SNP increased vessel diameter in a dose dependent manner and enhanced the mean red cell velocity measured with a fiber-optic laser-Doppler anemometer microscope (FLDAM). Blood flow, calculated from the mean red cell velocity and vessel diameters was increased significantly during infusion. In contrast, mean wall shear rates in the arterioles and venules were not changed by SNP infusion. The results indicated that SNP and SIN-1 possessed potent antithrombotic activities, whilst SNP increased cerebral blood flow without changing wall shear rate. The findings suggest that the NO released by SNP and SIN-1 may be beneficial for the treatment and protection of cerebral infarction

Studies on the Haemostatic Defect in a Complicated Syndrome

1995 ◽  
Vol 74 (05) ◽  
pp. 1244-1251 ◽  
Author(s):  
H Stormorken ◽  
H Holmsen ◽  
R Sund ◽  
K S Sakariassen ◽  
T Hovig ◽  
...  
Keyword(s):  
Ex Vivo ◽  
Bleeding Tendency ◽  
Clot Retraction ◽  
Abnormal Finding ◽  
Shear Rates ◽  
Perfusion Chamber ◽  
Coagulant Activity ◽  
5 Ht Uptake ◽  
And Storage

SummaryThe Stormorken syndrome is a multifacetted syndrome including a bleeding tendency. No deviations were found in the coagulation- or fibrinolytic systems. Platelet number was low normal, and size abnormal, whereas EM findings were unremarkable. Survival time was half normal. Clot retraction was initially rapid, but clearly decreased, whereas prothrombin consumption was also initially rapid, but complete. Membrane GP’s were normal, so was AA metabolism, PI-cycle, granule storage and secretion, and c-AMP function, whereas 5-HT uptake and storage was decreased. Optical platelet aggregation was low normal with all physiological agonists. The only clearly abnormal finding was that coagulant activity was present on non stimulated platelets at the same level as kaolin-stimulated normal platelets. This indicated a platelet abnormality which should lead to a thrombogenic, not to a haemorrhagic trait. This paradox may have its origin in rheology, because when challenged with in vivo shear rates in an ex vivo perfusion chamber, platelet cohesion was abnormally low. Further studies to better delineate the membrane abnormality are underway.

LACK OF EFFECT OF CORTICOSTEROIDS ON THE IN VIVO DISAPPEARANCE OF SULFHYDRYL-INHIBITED AND ANTIBODY-COATED ERYTHROCYTES

1964 ◽  
Vol 47 (3_Suppl) ◽  
pp. S28-S36
Author(s):  
Kailash N. Agarwal
Keyword(s):  
Red Cells ◽  
List Type ◽  
Red Cell

ABSTRACT Red cells were incubated in vitro with sulfhydryl inhibitors and Rhantibody with and without prior incubation with prednisolone-hemisuccinate. These erythrocytes were labelled with Cr51 and P32 and their disappearance in vivo after autotransfusion was measured. Prior incubation with prednisolone-hemisuccinate had no effect on the rate of red cell disappearance. The disappearance of the cells was shown to take place without appreciable intravascular destruction.

INFLUENCE OF GROWTH REGULATORS AND LED IRRADIATORS ON PINE STRAWBERRY ADAPTATION

1970 ◽  
pp. 12-15
Author(s):  
M. G. Markova ◽  
E. N. Somova
Keyword(s):  
Surface Area ◽  
Growth Regulators ◽  
Leaf Surface ◽  
Combined Treatment ◽  
Fragaria X Ananassa ◽  
Leaf Surface Area ◽  
External Conditions ◽  
Light Effects ◽  
Control Version

Work on going through the adaptation stage of rooted micro-stalks comes down to searching for new growth regulators and studying the influence of external conditions, which include, among other things, light effects. The data of 2018-2019 on the effect of growth regulators Siliplant, EcoFus and experimental LED phytoradiators on the adaptation of rooted micro-stalks of garden strawberries (Fragaria x ananassa duch) in vivo are presented. The object of research is rooted micro-stalks of garden strawberries of the Korona variety. It was revealed that, at the adaptation stage of rooted micro-stalks of strawberries, the most effective was the treatment of plants by spraying with Siliplant at a concentration of 1.0 ml/l and the combined treatment with Siliplant and EcoFus at concentrations of 0.5 ml/l: regardless of lighting, the survival rate averaged 99.4 - 99.7%, the leaf surface area increased significantly from 291.85 mm2 to 334.4 mm2. The number of normally developed leaves of strawberry microplants increased significantly after treatment with all preparations from 3.5 to 6.0, 5.8 and 6.5 pcs/plant, and a significant increase in the height of strawberry rosettes was facilitated by treatment with Siliplant and Siliplant together with EcoFus. Regardless of growth regulators, the most effective was the experimental LED phyto-irradiator with a changing spectrum, which contributed to an increase in leaf surface area, height of rosettes and the number of normally developed leaves in strawberry microplants. When illuminated with a flashing phytoradiator, these indicators are lower than in the control version, but not significantly. By the end of the rooting stage, all microplants of garden strawberries corresponded to GOST R 54051-2010.

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