Characterization of red blood cell metabolism in rainbow trout

1990 ◽  
Vol 154 (1) ◽  
pp. 475-489 ◽  
Author(s):  
P. J. Walsh ◽  
C. M. Wood ◽  
S. Thomas ◽  
S. F. Perry

Red blood cell metabolism was studied in vitro using whole blood obtained by catheter from resting rainbow trout (Oncorhynchus mykiss). Preparations were viable as shown by stable NTP, metabolite and catecholamine levels and acid-base status, all of which remained at in vivo levels over the 2 h incubation period. Enzymes diagnostic of glycolysis, the tricarboxylic acid (TCA) cycle and phosphagen metabolism were all present in significant amounts in red blood cells. In direct comparisons of 14C-labelled substrates at normal resting plasma concentrations, rates of CO2 production were in the order: glucose greater than lactate greater than alanine greater than oleate. Total CO2 production rates from these four oxidative substrates did not equal directly measured O2 consumption rates, indicating that other substrates may also be important in vivo. Oxidative pathway Km values for glucose (8.4 mmol l-1), lactate (3.3 mmol l-1) and alanine (0.8 mmol l-1) were well within the normal physiological ranges of plasma concentrations. Glucose concentration did not affect lactate oxidation rates, but there was some inhibition (27%) of glucose oxidation by high lactate concentrations (20 mmol l-1). The observed Km values and competitive interactions suggest that changes in plasma concentrations associated with environmental stresses can considerably alter the relative rates of oxidation of glucose and lactate in vivo. Considerable pentose-phosphate shunt activity was detected in red cells, as indicated by high activities of glucose-6-phosphate dehydrogenase and 6-phosphogluconate dehydrogenase and high CO2 production rates from (1–14C)-labelled glucose. Even in the presence of normal O2 levels, a significant percentage (28%) of glucose metabolism was directed to lactate production. Taken together, these results demonstrate that rainbow trout whole blood incubated in vitro constitutes a dynamic and viable system for metabolic studies at the pathway level.

1991 ◽  
Vol 156 (1) ◽  
pp. 233-248 ◽  
Author(s):  
S. THOMAS ◽  
R. KINKEAD ◽  
P. J. WALSH ◽  
C. M. WOOD ◽  
S. F. PERRY

The sensitivity of red blood cell Na+/H+ exchange to exogenous adrenaline was assessed in vitro using blood withdrawn from catheterized rainbow trout (Oncorhynchus mykiss) maintained under normoxic conditions [water PO2, (PwO2)=20.66 kPa] or after exposure to moderate hypoxia (PwO2=6.67-9.33 kPa) for 48 h, which chronically elevated plasma adrenaline, but not noradrenaline, levels. Peak changes in whole-blood extracellular pH over a 30 min period after adding 50–1000 nmoll−1 adrenaline were employed as an index of sensitivity; the blood was pre-equilibrated to simulate arterial blood gas tensions in severely hypoxic fish (PaO2=2.0 kPa, PaCO2=0.31 kPa). Blood pooled from normoxic fish displayed a dose-dependent reduction in whole-blood pH after addition of adrenaline. Blood pooled from three separate groups of hypoxic fish, however, displayed diminished sensitivity to adrenaline, ranging from complete desensitization to a 60%reduction of the response. Subsequent experiments performed on blood from individual (i.e. not pooled) normoxic or hypoxic fish demonstrated an inverse correlation between the intensity of H+ extrusion (induced by exogenous adrenaline addition) and endogenous plasma adrenaline levels at the time of blood withdrawal. However, acute increases in plasma adrenaline levels in vitro did not affect the responsiveness of the red blood cell to subsequent adrenergic stimulation. The intensity of H+ extrusion was inversely related to the PaO2in vivo between 2.67 and 10.66 kPa, and directly related to the logarithm of the endogenous plasma adrenaline level. The results suggest that desensitization of Na+/H+ exchange in chronically hypoxic fish is related to persistent elevation of levels of this catecholamine. This desensitization can be reversed in vitro as a function of time, but only when blood is maintained under sufficiently aerobic conditions.


Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2890-2890
Author(s):  
Rodrigo Morales ◽  
Kimberley A. Buytaert-Hoefen ◽  
Eric T. Hansen ◽  
Dennis Hlavinka ◽  
Raymond Goodrich ◽  
...  

Abstract Although prion diseases are rare in humans, the established link between a new variant form of CJD (vCJD) and the consumption of cattle meat contaminated by BSE have raised concerns about a possible outbreak of a large epidemic in the human population. Over the past few years, BSE has become a significant health concern in several countries, and it now seems apparent that vCJD can also be iatrogenically transmitted from human to human by blood transfusion. Exacerbating this state of affairs is the lack of a reliable test to identify individuals incubating the disease during the long and silent period from the onset of infection to the appearance of clinical symptoms. The purpose of this research study was to evaluate the effectiveness of separation of whole blood and washing of the red cell fraction for the removal of infectious scrapie prion protein (PrPSc) from red blood cell (RBC) suspensions. Samples of human, whole blood were spiked with 5 × 106 LD50 263K PrPSc. Analysis of the treated sample supernatants by Western blot revealed that approximately >88% of the PrPSc was removed with the initial plasma expression and the equivalent of 6% was detected in a saline wash (300 mL; 0.9% saline). The final sample of RBCs revealed no detectable levels of PrPSc by Western blots. Further analysis of the treated RBCs using the PMCA assay indicated detectable amounts of PrPSc only after 2 consecutive amplification rounds. Semi-quantitative analysis of PMCA amplification enabled us to estimate that the treated RBCs contained less than 1 × 104 LD50 PrPSc. This corresponded to removal levels exceeding ≥99% of spiked material in whole blood. These in vitro estimations were confirmed by in vivo infectivity studies in a hamster model of disease transmission. Results from in vivo studies displayed significant differences in the incubation periods of the spiked blood inoculated hamsters (100.1 ± 1.7) versus washed RBCs (135.8 ± 6.7). Moreover, a substantial difference in the attack rate (6/15: 40% in washed RBC, versus 13/13: 100% in spiked blood) further indicated a substantial removal of infectious prions. Comparison of this data with results of animals inoculated with different dilutions of infectious material, indicated a >99.94% reduction of infectivity. Washed, packed human red cells produced by this procedure were able to be stored in standard additive solutions (AS-3) for 42 days while still meeting all in vitro blood bank standards for acceptable red cell quality. Conclusion This data suggests that separation of plasma coupled with a simple, low volume wash of red cells may represent an efficient method to remove prions from red blood cell fractions, thus reducing possible infectivity of these products.


Author(s):  
Adam Attila Matrai ◽  
Gabor Varga ◽  
Bence Tanczos ◽  
Barbara Barath ◽  
Adam Varga ◽  
...  

BACKGROUND: The effects of temperature on micro-rheological variables have not been completely revealed yet. OBJECTIVE: To investigate micro-rheological effects of heat treatment in human, rat, dog, and porcine blood samples. METHODS: Red blood cell (RBC) - buffer suspensions were prepared and immersed in a 37, 40, and 43°C heat-controlled water bath for 10 minutes. Deformability, as well as mechanical stability of RBCs were measured in ektacytometer. These tests were also examined in whole blood samples at various temperatures, gradually between 37 and 45°C in the ektacytometer. RESULTS: RBC deformability significantly worsened in the samples treated at 40 and 43°C degrees, more expressed in human, porcine, rat, and in smaller degree in canine samples. The way of heating (incubation vs. ektacytometer temperation) and the composition of the sample (RBC-PBS suspension or whole blood) resulted in the different magnitude of RBC deformability deterioration. Heating affected RBC membrane (mechanical) stability, showing controversial alterations. CONCLUSION: Significant changes occur in RBC deformability by increasing temperature, showing inter-species differences. The magnitude of alterations is depending on the way of heating and the composition of the sample. The results may contribute to better understanding the micro-rheological deterioration in hyperthermia or fever.


PLoS ONE ◽  
2015 ◽  
Vol 10 (8) ◽  
pp. e0136885 ◽  
Author(s):  
Stéphane Kerbrat ◽  
Benoit Vingert ◽  
Marie-Pierre Junier ◽  
Flavia Castellano ◽  
François Renault-Mihara ◽  
...  

1972 ◽  
Vol 51 (3) ◽  
pp. 566-574 ◽  
Author(s):  
Frank G. De Furia ◽  
Denis R. Miller ◽  
Anthony Cerami ◽  
James M. Manning

1987 ◽  
Author(s):  
M T Santos ◽  
J Aznar ◽  
J Valles ◽  
J L Perez-Reguejo

RBC stimulate the initial stages of platelet activation by collagen as evaluated by the BASIC wave (Perez-Requejo et al. Thromb Haemostas 54:799 1985). In order to get some insight into the mechanisms of platelet-RBC interactions, a BASIC wave was induced by lug/ml of collagen after mixing "in vitro" platelets and RBC obtained both before and two hours after a single dose of 500 mg of ASA from normal subjects. The TXB2 formed was also evaluated. The results show (Table) that non aspirinized RBC (non-ASA-RBC) increase the BASIC wave intensity of aspirinized platelets (ASA-PRP) by a cyclooxygenase-independent pathway since no increase in TXB2 was observed (Exp 1), while both non-ASA-RBC (Exp 2) and ASA-RBC (Exp 3) activate non-ASA platelets with theparticipation of the cyclooxygenase system, since an increase in TXA2 was found.A comparison of the effect of non-ASA-RBC (Exp 1) and ASA-RBC (Exp 4) on aspirinized platelets shows that ASA modifies the RBC behaviour associated with estimulation of platelets by a cyclooxygenase-independent pathway. This effect of ASA on RBC is nottransient and lasts at least 48 hours after ASA ingestion. In addition, when asmall proportion of nonASA platelets (10%) is mixed with aspirinized platelets(90%) and ASA-RBC - a situation that can be encountered "in vivo" inthe hours following ASA ingestion - the intensity of the BASIC wave is 89% of that obtained when all the platelets are non aspirinized. This RBC effect on the mixtureof ASA and nonASA platelets, may help explain the sometimes contradictory effect of ASA as an antithrombotic agent.


Blood ◽  
1999 ◽  
Vol 94 (6) ◽  
pp. 1915-1925 ◽  
Author(s):  
Reuben Kapur ◽  
Ryan Cooper ◽  
Xingli Xiao ◽  
Mitchell J. Weiss ◽  
Peter Donovan ◽  
...  

Abstract Stem cell factor (SCF) is expressed as an integral membrane growth factor that may be differentially processed to produce predominantly soluble (S) (SCF248) or membrane-associated (MA) (SCF220) protein. A critical role for membrane presentation of SCF in the hematopoietic microenvironment (HM) has been suggested from the phenotype of the Steel-dickie(Sld) mice, which lack MA SCF, and by studies performed in our laboratory (and by others) using long-term bone marrow cultures and transgenic mice expressing different SCF isoforms.Steel17H (Sl17H) is an SCF mutant that demonstrates melanocyte defects and sterility in males but not in females. The Sl17H allele contains a intronic mutation resulting in the substitution of 36 amino acids (aa’s) in the SCF cytoplasmic domain with 28 novel aa’s. This mutation, which affects virtually the entire cytoplasmic domain of SCF, could be expected to alter membrane SCF presentation. To investigate this possibility, we examined the biochemical and biologic properties of the Sl17H-encoded protein and its impact in vivo and in vitro on hematopoiesis and on c-Kit signaling. We demonstrate that compound heterozygous Sl/Sl17H mice manifest multiple hematopoietic abnormalities in vivo, including red blood cell deficiency, bone marrow hypoplasia, and defective thymopoiesis. In vitro, both S and MA Sl17H isoforms of SCF exhibit reduced cell surface expression on stromal cells and diminished biological activity in comparison to wild-type (wt) SCF isoforms. These alterations in presentation and biological activity are associated with a significant reduction in the proliferation of an SCF-responsive erythroid progenitor cell line and in the activation of phosphatidylinositol 3-Kinase/Akt and mitogen-activated protein-Kinase signaling pathways. In vivo, transgene expression of the membrane-restricted (MR) (SCFX9/D3) SCF in Sl/Sl17H mutants results in a significant improvement in peripheral red blood cell counts in comparison toSl/Sl17H mice.


Blood ◽  
1999 ◽  
Vol 94 (9) ◽  
pp. 3037-3047 ◽  
Author(s):  
Jack Levin ◽  
Jin-Peng Peng ◽  
Georgiann R. Baker ◽  
Jean-Luc Villeval ◽  
Patrick Lecine ◽  
...  

Abstract Expression of the p45 subunit of transcription factor NF-E2 is restricted to selected blood cell lineages, including megakaryocytes and developing erythrocytes. Mice lacking p45 NF-E2 show profound thrombocytopenia, resulting from a late arrest in megakaryocyte differentiation, and a number of red blood cell defects, including anisocytosis and hypochromia. Here we report results of studies aimed to explore the pathophysiology of these abnormalities. Mice lacking NF-E2 produce very few platelet-like particles that display highly disorganized ultrastructure and respond poorly to platelet agonists, features consistent with the usually lethal hemorrhage in these animals. Thrombocytopenia was evident during fetal life and was not corrected by splenectomy in adults. Surprisingly, fetal NF-E2–deficient megakaryocyte progenitors showed reduced proliferation potential in vitro. Thus, NF-E2 is required for regulated megakaryocyte growth as well as for differentiation into platelets. All the erythroid abnormalities were reproduced in lethally irradiated wild-type recipients of hematopoietic cells derived from NF-E2-null fetuses. Whole blood from mice lacking p45 NF-E2 showed numerous small red blood cell fragments; however, survival of intact erythrocytes in vivo was indistinguishable from control mice. Considered together, these observations indicate a requirement for NF-E2 in generating normal erythrocytes. Despite impressive splenomegaly at baseline, mice lacking p45 NF-E2 survived splenectomy, which resulted in increased reticulocyte numbers. This reveals considerable erythroid reserve within extra-splenic sites of hematopoiesis and suggests a role for the spleen in clearing abnormal erythrocytes. Our findings address distinct aspects of the requirements for NF-E2 in blood cell homeostasis and establish its roles in proper differentiation of megakaryocytes and erythrocytes.


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