Kinetics of chloride transport across fish red blood cell membranes

1995 ◽  
Vol 198 (10) ◽  
pp. 2237-2244 ◽  
Author(s):  
F Jensen ◽  
J Brahm
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Atlantic Cod ◽  
Chloride Transport ◽  
Band 3 ◽  
Transport Kinetics ◽  
Human Values ◽  
Cl Transport ◽  
Kinetics Of

The continuous flow tube method was used to investigate the kinetics of chloride transport, and its potential oxygenation-dependency, in red blood cells (RBCs) from four teleost fish species and man. A significant interspecific variation in Cl- transport kinetics was found. At 15 °C, the rate constant k for unidirectional 36Cl- efflux was significantly lower in RBCs from eel and carp than in RBCs from rainbow trout and Atlantic cod. The values of k of cod RBCs at 15 °C and of human RBCs at 37 °C were not significantly different. The volume and surface area of the RBCs were evaluated and used to calculate the apparent membrane permeability to Cl- (PCl). The magnitude of PCl followed the sequence: eel<carp<trout¾cod. PCl values in trout and cod at 15 °C were similar to human values at 37 °C. An extrapolation of human values to 15 °C revealed that the Cl- shift at this temperature was considerable faster in all four teleosts than in man. This illustrates appropriate adaption of band-3-mediated anion transport to the different temperature regimes encountered by fish and mammals. The Cl- transport kinetics did not differ significantly between oxygenated and deoxygenated RBCs in any of the species examined. The apparent absence of any effect of a change in haemoglobin oxygen-saturation may be related to the presence of a flexible link which results in minimal interaction between the membrane domain (mediating Cl- transport) and the cytoplasmic domain (to which oxygenation-dependent haemoglobin binding occurs) of band 3. In carp, Cl- transport kinetics were not influenced by pH over the extracellular pH (pHe) range 7.6­8.36, which spans the in vivo pHe range. The data are discussed in relation to the rate-limiting role of red blood cell HCO3-/Cl- exchange for CO2 excretion.

K562 cell anion exchange differs markedly from that of mature red blood cells

1983 ◽  
Vol 244 (1) ◽  
pp. C68-C74 ◽  
Author(s):  
F. Y. Law ◽  
R. Steinfeld ◽  
P. A. Knauf
Keyword(s):  
Blood Cell ◽  
Red Blood Cells ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Chloride Transport ◽  
K562 Cells ◽  
Band 3 ◽  
Anion Transport ◽  
Leukemic Cells ◽  
Anion Transport System

Human K562 leukemic cells exhibit several erythroid properties, including synthesis and expression of the major red blood cell sialoglycoprotein, glycophorin. This has led us to ask if these cells express a functional anion transport system analogous to that which is associated with the other major erythrocyte glycoprotein, band 3. The chloride-36 exchange flux in K562 cells is less than 0.6% of that which would be expected in mature erythrocytes under similar conditions. Unlike red blood cells, K562 cells do not exhibit a high chloride-sulfate selectivity, and various agents that inhibit red blood cell chloride exchange are all much less effective in K562 cells. On the basis of these flux measurements, K562 cells probably contain less than 600 fully functional red blood cell-like band 3 molecules per cell, in contrast to about a million molecules in the mature red blood cell. The possible-existence of greatly altered band 3 molecules with a reduced turnover rate and/or a reduced affinity for chloride and for various inhibitors is unlikely but cannot be completely excluded. Anion transport was also measured in K562 cells that had been induced to increase hemoglobin synthesis by various chemical agents. Even under these conditions, chloride fluxes indicated no substantial increase in the number of functional anion transport sites or their chloride transport rate.

Asynchronous synthesis of membrane skeletal proteins during terminal maturation of murine erythroblasts

Blood ◽  
1992 ◽  
Vol 80 (2) ◽  
pp. 530-539 ◽  
Author(s):  
M Hanspal ◽  
JS Hanspal ◽  
R Kalraiya ◽  
SC Liu ◽  
KE Sahr ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Messenger Rna ◽  
Membrane Skeleton ◽  
Band 3 ◽  
Metabolic Labeling ◽  
Mrna Levels ◽  
Long Term Stability

To study the changes in the synthesis of the major membrane skeletal proteins, their assembly on the membrane, and their turnover during terminal red blood cell maturation in vivo, we have compared early proerythroblasts and late erythroblasts obtained from the spleens of mice at different times after infection with the anemia-inducing strain of Friend virus (FVA). Metabolic labeling of these cells indicates striking differences between early and late erythroblasts. In early erythroblasts, spectrin and ankyrin are synthesized in large amounts in the cytosol with proportionately high levels of spectrin and ankyrin messenger RNA (mRNA). In contrast, only small amounts of these polypeptides are incorporated into the skeleton, which is markedly unstable. In late erythroblasts, however, the synthesis of spectrin and ankyrin and their mRNA levels are substantially reduced, yet the net amounts of these polypeptides assembled in the membrane skeleton are markedly increased, and the membrane skeleton becomes stable with no detectable protein turnover. The mRNA levels and the synthesis of the band 3 and 4.1 proteins are increased considerably in terminally differentiated normoblasts with a concomitant increase in the net amount and the half-life of the newly assembled spectrin and ankyrin. Thus, the increased accumulation of spectrin and ankyrin at the late erythroblast stage is a consequence of an increased recruitment of these proteins on the membrane and an increase in their stability rather than a transcriptional upregulation. This is in contrast to band 3 and 4.1 proteins, which accumulate in direct proportion to their mRNA levels and rates of synthesis. These results suggest a key role for the band 3 and 4.1 proteins in conferring a long-term stability to the membrane skeleton during terminal red blood cell differentiation.

scholarly journals CATECHOLAMINE-ACTIVATED SODIUM/PROTON EXCHANGE IN THE RED BLOOD CELLS OF THE MARINE TELEOST GADUS MORHUA

1994 ◽  
Vol 192 (1) ◽  
pp. 253-267 ◽  
Author(s):  
M Berenbrink ◽  
C Bridges
Keyword(s):  
Blood Cell ◽  
Red Blood Cells ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Proton Exchange ◽  
Buffer System ◽  
Sodium Proton Exchanger

The effects of catecholamines on the pH and the cellular ion and water content were investigated in red blood cells from the Atlantic cod (Gadus morhua). Noradrenaline induced a rapid decrease in the extracellular pH (pHe) of red blood cells suspended in a CO2/bicarbonate or in a CO2/bicarbonate-free buffer system. The noradrenaline-induced changes in pHe were a saturable function of the external sodium ion concentration and were inhibited by amiloride but not by DIDS (4,4'-diisothiocyanatostilbene-2,2'-disulphonic acid, final concentration of both 10(-4) mol l-1). The catecholamine-induced extracellular acidification was accompanied by an intracellular alkalization and protons were moved from their electrochemical equilibrium. Proton extrusion was associated with an increase in the red blood cell sodium and chloride concentrations. In the presence of DIDS, the chloride movements were blocked and the net proton efflux under these conditions matched the net sodium influx. The results strongly suggested the activation of a sodium/proton exchanger by catecholamines in the red blood cells of the Atlantic cod. The red blood cell receptor affinity for adrenaline was three times higher than that for noradrenaline. Comparison with data in the literature for in vivo catecholamine concentrations indicated that adrenaline was more effective than noradrenaline in activating the red blood cell sodium/proton exchanger in the Atlantic cod in vivo.

scholarly journals Asynchronous synthesis of membrane skeletal proteins during terminal maturation of murine erythroblasts

Blood ◽  
1992 ◽  
Vol 80 (2) ◽  
pp. 530-539 ◽  
Author(s):  
M Hanspal ◽  
JS Hanspal ◽  
R Kalraiya ◽  
SC Liu ◽  
KE Sahr ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Messenger Rna ◽  
Membrane Skeleton ◽  
Band 3 ◽  
Metabolic Labeling ◽  
Mrna Levels ◽  
Long Term Stability

Abstract To study the changes in the synthesis of the major membrane skeletal proteins, their assembly on the membrane, and their turnover during terminal red blood cell maturation in vivo, we have compared early proerythroblasts and late erythroblasts obtained from the spleens of mice at different times after infection with the anemia-inducing strain of Friend virus (FVA). Metabolic labeling of these cells indicates striking differences between early and late erythroblasts. In early erythroblasts, spectrin and ankyrin are synthesized in large amounts in the cytosol with proportionately high levels of spectrin and ankyrin messenger RNA (mRNA). In contrast, only small amounts of these polypeptides are incorporated into the skeleton, which is markedly unstable. In late erythroblasts, however, the synthesis of spectrin and ankyrin and their mRNA levels are substantially reduced, yet the net amounts of these polypeptides assembled in the membrane skeleton are markedly increased, and the membrane skeleton becomes stable with no detectable protein turnover. The mRNA levels and the synthesis of the band 3 and 4.1 proteins are increased considerably in terminally differentiated normoblasts with a concomitant increase in the net amount and the half-life of the newly assembled spectrin and ankyrin. Thus, the increased accumulation of spectrin and ankyrin at the late erythroblast stage is a consequence of an increased recruitment of these proteins on the membrane and an increase in their stability rather than a transcriptional upregulation. This is in contrast to band 3 and 4.1 proteins, which accumulate in direct proportion to their mRNA levels and rates of synthesis. These results suggest a key role for the band 3 and 4.1 proteins in conferring a long-term stability to the membrane skeleton during terminal red blood cell differentiation.

Effects of Preloading of Stannous Compounds on the Distribution of 99mTc-Pertechnetate

1977 ◽  
Vol 16 (01) ◽  
pp. 26-29 ◽  
Author(s):  
D. D. Greenberg ◽  
P. Som ◽  
G. E. Meinken ◽  
D. F. Sacker ◽  
H. L. Atkins ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Plasma Ratio ◽  
99Mtc Pertechnetate ◽  
Time Period ◽  
Stannous Ion ◽  
Distribution Studies

Summary 99mTc-pertechnetate distribution studies were performed in rabbits and mice following pretreatment between 5—336 hours with various routinely used stannous complexes (HSA, MAA, GHT, DTPA, PYPs) containing different amounts of Sn++ (0.17 —15.0 μ mg/kg). Beyond a concentration of 0.26 mg/kg of Sn++ an alteration in 99mTc-pertechnetate distribution was observed. The red blood cell was found to be the most prominent target. An in-vivo reduction of 99mTc-pertechnetate apparently occurred by the presence of stannous ion within the red blood cell. Preloading time period between 5—24 hours did not alter the uptake of RBC/plasma ratio. Beyond that period it decreased slowly and still persisted up to 2 weeks following pretreatment. RBC/ plasma ratio of 99mTcO4 - increased with increased Sn++ content of various commercially available pharmaceutical kits.

scholarly journals Anti-tumor effects of RTX-240: an engineered red blood cell expressing 4-1BB ligand and interleukin-15

2021 ◽  
Author(s):  
Shannon L. McArdel ◽  
Anne-Sophie Dugast ◽  
Maegan E. Hoover ◽  
Arjun Bollampalli ◽  
Enping Hong ◽  
...  
Keyword(s):  
T Cells ◽  
T Cell ◽  
Blood Cell ◽  
Nk Cells ◽  
Red Blood Cell ◽  
Safety Profile ◽  
Nk Cell ◽  
Cell Activity ◽  
In Vivo Studies

AbstractRecombinant agonists that activate co-stimulatory and cytokine receptors have shown limited clinical anticancer utility, potentially due to narrow therapeutic windows, the need for coordinated activation of co-stimulatory and cytokine pathways and the failure of agonistic antibodies to recapitulate signaling by endogenous ligands. RTX-240 is a genetically engineered red blood cell expressing 4-1BBL and IL-15/IL-15Rα fusion (IL-15TP). RTX-240 is designed to potently and simultaneously stimulate the 4-1BB and IL-15 pathways, thereby activating and expanding T cells and NK cells, while potentially offering an improved safety profile through restricted biodistribution. We assessed the ability of RTX-240 to expand and activate T cells and NK cells and evaluated the in vivo efficacy, pharmacodynamics and tolerability using murine models. Treatment of PBMCs with RTX-240 induced T cell and NK cell activation and proliferation. In vivo studies using mRBC-240, a mouse surrogate for RTX-240, revealed biodistribution predominantly to the red pulp of the spleen, leading to CD8 + T cell and NK cell expansion. mRBC-240 was efficacious in a B16-F10 melanoma model and led to increased NK cell infiltration into the lungs. mRBC-240 significantly inhibited CT26 tumor growth, in association with an increase in tumor-infiltrating proliferating and cytotoxic CD8 + T cells. mRBC-240 was tolerated and showed no evidence of hepatic injury at the highest feasible dose, compared with a 4-1BB agonistic antibody. RTX-240 promotes T cell and NK cell activity in preclinical models and shows efficacy and an improved safety profile. Based on these data, RTX-240 is now being evaluated in a clinical trial.

scholarly journals Absence of the Adaptor Protein PEA-15 Is Associated with Altered Pattern of Th Cytokines Production by Activated CD4+ T Lymphocytes In Vitro, and Defective Red Blood Cell Alloimmune Response In Vivo

PLoS ONE ◽  
2015 ◽  
Vol 10 (8) ◽  
pp. e0136885 ◽  
Author(s):  
Stéphane Kerbrat ◽  
Benoit Vingert ◽  
Marie-Pierre Junier ◽  
Flavia Castellano ◽  
François Renault-Mihara ◽  
...  
Keyword(s):  
T Lymphocytes ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Adaptor Protein

In vivo microvascular structural and functional consequences of muscle length changes

1997 ◽  
Vol 272 (5) ◽  
pp. H2107-H2114 ◽  
Author(s):  
D. C. Poole ◽  
T. I. Musch ◽  
C. A. Kindig
Keyword(s):  
Blood Flow ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Oxygen Delivery ◽  
Sarcomere Length ◽  
Flow Dynamics ◽  
Capillary Diameter ◽  
Luminal Diameter ◽  
Length Changes

As muscles are stretched, blood flow and oxygen delivery are compromised, and consequently muscle function is impaired. We tested the hypothesis that the structural microvascular sequellae associated with muscle extension in vivo would impair capillary red blood cell hemodynamics. We developed an intravital spinotrapezius preparation that facilitated direct on-line measurement and alteration of sarcomere length simultaneously with determination of capillary geometry and red blood cell flow dynamics. The range of spinotrapezius sarcomere lengths achievable in vivo was 2.17 +/- 0.05 to 3.13 +/- 0.11 microns. Capillary tortuosity decreased systematically with increases of sarcomere length up to 2.6 microns, at which point most capillaries appeared to be highly oriented along the fiber longitudinal axis. Further increases in sarcomere length above this value reduced mean capillary diameter from 5.61 +/- 0.03 microns at 2.4-2.6 microns sarcomere length to 4.12 +/- 0.05 microns at 3.2-3.4 microns sarcomere length. Over the range of physiological sarcomere lengths, bulk blood flow (radioactive microspheres) decreased approximately 40% from 24.3 +/- 7.5 to 14.5 +/- 4.6 ml.100 g-1.min-1. The proportion of continuously perfused capillaries, i.e., those with continuous flow throughout the 60-s observation period, decreased from 95.9 +/- 0.6% at the shortest sarcomere lengths to 56.5 +/- 0.7% at the longest sarcomere lengths and was correlated significantly with the reduced capillary diameter (r = 0.711, P < 0.01; n = 18). We conclude that alterations in capillary geometry and luminal diameter consequent to increased muscle sarcomere length are associated with a reduction in mean capillary red blood cell velocity and a greater proportion of capillaries in which red blood cell flow is stopped or intermittent. Thus not only does muscle stretching reduce bulk blood (and oxygen) delivery, it also alters capillary red blood cell flow dynamics, which may further impair blood-tissue oxygen exchange.

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