scholarly journals Desensitization of Adrenaline-Induced Red Blood Cell H+ Extrusion in Vitro After Chronic Exposure of Rainbow Trout to Moderate Environmental Hypoxia

1991 ◽  
Vol 156 (1) ◽  
pp. 233-248 ◽  
Author(s):  
S. THOMAS ◽  
R. KINKEAD ◽  
P. J. WALSH ◽  
C. M. WOOD ◽  
S. F. PERRY
Keyword(s):  
Rainbow Trout ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Whole Blood ◽  
Inverse Correlation ◽  
Adrenergic Stimulation ◽  
Plasma Adrenaline ◽  
Arterial Blood Gas ◽  
Arterial Blood

The sensitivity of red blood cell Na+/H+ exchange to exogenous adrenaline was assessed in vitro using blood withdrawn from catheterized rainbow trout (Oncorhynchus mykiss) maintained under normoxic conditions [water PO2, (PwO2)=20.66 kPa] or after exposure to moderate hypoxia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.

scholarly journals Time course of red blood cell intracellular pH recovery following short-circuiting in relation to venous transit times in rainbow trout, Oncorhynchus mykiss

2018 ◽  
Vol 315 (2) ◽  
pp. R397-R407 ◽  
Author(s):  
Till S. Harter ◽  
Alexandra G. May ◽  
William J. Federspiel ◽  
Claudiu T. Supuran ◽  
Colin J. Brauner
Keyword(s):  
Rainbow Trout ◽  
Blood Cell ◽  
Intracellular Ph ◽  
Red Blood Cell ◽  
Time Course ◽  
Ph Sensitive ◽  
Adrenergic Stimulation ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Athletic Ability

Accumulating evidence is highlighting the importance of a system of enhanced hemoglobin-oxygen (Hb-O2) unloading for cardiovascular O2 transport in teleosts. Adrenergically stimulated sodium-proton exchangers (β-NHE) create H+ gradients across the red blood cell (RBC) membrane that are short-circuited in the presence of plasma-accessible carbonic anhydrase (paCA) at the tissues; the result is a large arterial-venous pH shift that greatly enhances O2 unloading from pH-sensitive Hb. However, RBC intracellular pH (pHi) must recover during venous transit (31–90 s) to enable O2 loading at the gills. The halftimes ( t1/2) and magnitudes of RBC β-adrenergic stimulation, short-circuiting with paCA and recovery of RBC pHi, were assessed in vitro, on rainbow trout whole blood, and using changes in closed-system partial pressure of O2 as a sensitive indicator for changes in RBC pHi. In addition, the recovery rate of RBC pHi was assessed in a continuous-flow apparatus that more closely mimics RBC transit through the circulation. Results indicate that: 1) the t1/2 of β-NHE short-circuiting is likely within the residence time of blood in the capillaries, 2) the t1/2 of RBC pHi recovery is 17 s and within the time of RBC venous transit, and 3) after short-circuiting, RBCs reestablish the initial H+ gradient across the membrane and can potentially undergo repeated cycles of short-circuiting and recovery. Thus, teleosts have evolved a system that greatly enhances O2 unloading from pH-sensitive Hb at the tissues, while protecting O2 loading at the gills; the resulting increase in O2 transport per unit of blood flow may enable the tremendous athletic ability of salmonids.

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
Keyword(s):  
Rainbow Trout ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Whole Blood ◽  
Cell Metabolism ◽  
Plasma Concentrations ◽  
Co2 Production ◽  
Production Rates

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.

In vitro effects of temperature on red blood cell deformability and membrane stability in human and various vertebrate species

2021 ◽  
pp. 1-10
Author(s):  
Adam Attila Matrai ◽  
Gabor Varga ◽  
Bence Tanczos ◽  
Barbara Barath ◽  
Adam Varga ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Whole Blood ◽  
Mechanical Stability ◽  
Cell Deformability ◽  
Blood Samples ◽  
Effects Of Temperature ◽  
The Way ◽  
Rbc Deformability

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.

Reduction of Prion Infectivity in Packed Red Cells by Separation of Whole Blood and Washing of the Red Cell Fraction.

Blood ◽  
2007 ◽  
Vol 110 (11) ◽  
pp. 2890-2890
Author(s):  
Rodrigo Morales ◽  
Kimberley A. Buytaert-Hoefen ◽  
Eric T. Hansen ◽  
Dennis Hlavinka ◽  
Raymond Goodrich ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Whole Blood ◽  
Red Cells ◽  
Cell Fraction ◽  
Health Concern ◽  
Red Cell ◽  
New Variant

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.

Evaluation of overnight hold of whole blood at room temperature before component processing: effect of red blood cell (RBC) additive solutions on in vitro RBC measures

Transfusion ◽  
2011 ◽  
Vol 51 ◽  
pp. 15S-24S ◽  
Author(s):  
Pieter F. van der Meer ◽  
Jose A. Cancelas ◽  
Rebecca Cardigan ◽  
Dana V. Devine ◽  
Hans Gulliksson ◽  
...  
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Whole Blood ◽  
Room Temperature ◽  
Processing Effect

scholarly journals IN VITRO INTERACTIONS BETWEEN OXYGEN AND CARBON DIOXIDE TRANSPORT IN THE BLOOD OF THE SEA LAMPREY (PETROMYZON MARINUS)

1992 ◽  
Vol 173 (1) ◽  
pp. 25-41 ◽  
Author(s):  
R. A. Ferguson ◽  
N. Sehdev ◽  
B. Bagatto ◽  
B. L. Tufts
Keyword(s):  
Carbon Dioxide ◽  
Blood Cell ◽  
Red Blood Cells ◽  
Red Blood Cell ◽  
Whole Blood ◽  
Blood Cells ◽  
Sea Lamprey ◽  
Carbon Dioxide Transport ◽  
Dissociation Curves

In vitro experiments were carried out to examine the interactions between oxygen and carbon dioxide transport in the blood of the sea lamprey. Oxygen dissociation curves for whole blood obtained from quiescent lampreys had Hill numbers (nH) ranging from 1.52 to 1.89. The Bohr coefficient for whole blood was -0.17 when extracellular pH (pHe) was considered, but was much greater (-0.63) when red blood cell pH (pHi) was considered. The pHi was largely dependent on haemoglobin oxygen- saturation (SO2) and the pH gradient across the red blood cell membrane was often reversed when PCO2 was increased and/or SO2 was lowered. The magnitude of the increase in pHi associated with the Haldane effect ranged from 0.169 pH units at 2.9 kPa PCO2 to 0.453 pH units at a PCO2 of 0.2 kPa. Deoxygenated red blood cells had a much greater total CO2 concentration (CCO2) than oxygenated red blood cells, but the nonbicarbonate buffer value for the red blood cells was unaffected by oxygenation. Plasma CCO2 was not significantly different under oxygenated or deoxygenated conditions. Partitioning of CO2 carriage in oxygenated and deoxygenated blood supports recent in vivo observations that red blood cell CO2 carriage can account for much of the CCO2 difference between arterial and venous blood. Together, the results also suggest that oxygen and carbon dioxide transport may not be tightly coupled in the blood of these primitive vertebrates. Finally, red cell sodium concentrations were dependent on oxygen and carbon dioxide tensions in the blood, suggesting that sodium-dependent ion transport processes may contribute to the unique strategy for gas transport in sea lamprey blood.

In vitro analysis of volume and pH regulation in the red blood cells of a primitive air-breathing fish, the bowfin, Amia calva

1994 ◽  
Vol 72 (2) ◽  
pp. 280-286 ◽  
Author(s):  
B. L. Tufts ◽  
R. C. Drever ◽  
B. Bagatto ◽  
B. A. Cameron
Keyword(s):  
Rainbow Trout ◽  
Blood Cell ◽  
Red Blood Cells ◽  
Red Blood Cell ◽  
Blood Cells ◽  
Disulfonic Acid ◽  
Osmotic Swelling ◽  
Ph Range ◽  
Amia Calva

In the bowfin (Amia calva), a decrease in extracellular pH in vitro was associated with an increase in the water content and chloride concentration in the red blood cells that could be inhibited by the anion-exchange blocker, 4,4′-diisothiocyanatostilbene-2,2′-disulfonic acid (DIDS). After a step increase in CO2 tension, the extracellular total CO2 concentration was also significantly reduced by DIDS. Finally, over most of the experimental pH range, the red blood cell pH observed in the presence of DIDS was significantly elevated compared with that of controls. Taken together, these results indicate that as in most other fishes, chloride–bicarbonate exchange is clearly present and functional in bowfin red blood cells. Moreover, within the physiological pH range, ion movements across the anion exchanger have a marked influence on both the volume and the pH of bowfin red blood cells. In sharp contrast to the rainbow trout (Oncorhynchus mykiss), catecholamines had no effect on the volume, pH, or intracellular sodium concentration of red blood cells in the bowfin. Following osmotic swelling, rainbow trout red blood cells were able to regulate their volume back to control levels within 2 h. In the bowfin, however, there was no regulation of red blood cell volume after osmotic swelling. Thus, in contrast to many other fishes examined to date, it would appear that in the bowfin, the physiological mechanisms involved in the adrenergic response and in the regulatory volume decrease after osmotic swelling may be less active or possibly even absent in the red blood cells.

Adrenergic stimulation of glycolysis without change in glycolytic enzyme binding in rainbow trout (Oncorhynchus mykiss) erythrocytes

1994 ◽  
Vol 72 (5) ◽  
pp. 950-953 ◽  
Author(s):  
Dawn H. Sephton ◽  
William R. Driedzic
Keyword(s):  
Rainbow Trout ◽  
Oncorhynchus Mykiss ◽  
Whole Blood ◽  
Glycolytic Enzyme ◽  
Adrenergic Stimulation ◽  
Enzyme Binding ◽  
Rainbow Trout Oncorhynchus Mykiss ◽  
Cell Membrane Binding ◽  
Stimulation Of

Whole blood from rainbow trout (Oncorhynchus mykiss) was incubated in vitro with pharmacological levels of isoproterenol. The adrenergic stimulation of glycolysis in erythrocytes (RBCs) was assessed by monitoring the rate of 14C incorporation from [6-14C]-glucose into the acid-soluble RBC fraction. During a 3-h in vitro incubation, incorporation of label into the acid-soluble RBC fraction of isoproterenol-treated whole blood (0.25 ± 0.04 μmol glucose∙mL−1 RBC∙h−1) was higher than into untreated blood (0.08 ± 0.01 μmol glucose∙mL−1 RBC∙h−1). The percentage of cell membrane binding for phosphofructokinase, aldolase, and glyceraldehyde-3-phosphate dehydrogenase ranged from 17 to 35% and was not altered by adrenergic stimulation. Adrenergic stimulation activates glycolysis in rainbow trout RBCs but not through the modulation of enzyme binding.

scholarly journals The effects of repeated physical stress on the b-adrenergic response of the rainbow trout red blood cell

1996 ◽  
Vol 199 (3) ◽  
pp. 549-562 ◽  
Author(s):  
S Perry ◽  
S Reid ◽  
A Salama
Keyword(s):  
Rainbow Trout ◽  
Cyclic Amp ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Stress Responses ◽  
Physical Stress ◽  
Beta Adrenergic ◽  
Beta Adrenoceptors ◽  
Adrenergic Response

The effects of a 7-day period of daily physical stress (chasing until exhaustion) on the beta-adrenergic response of the rainbow trout (Oncorhynchus mykiss) red blood cell (rbc) were examined in vitro. Physical stress was associated with pronounced increases in the circulating levels of the catecholamine hormones (adrenaline and noradrenaline) measured on days 1, 3 and 7 of the stress regime. After 7 days, the numbers of high-affinity cell surface beta-adrenoceptors were reduced in the physically stressed fish when measured in vitro under conditions of normoxia (20 % reduction) or hypoxia (30 % reduction). Under hypoxic conditions, the binding affinity of the rbc beta-adrenoceptor was significantly higher in the stressed fish. Although the stressed fish had fewer beta-adrenoceptors, rbc adrenergic responsiveness was enhanced after 7 days of physical stress as determined from dose-response curves relating noradrenaline concentration to water and Na+ accumulation (indices of rbc adrenergic Na+/H+ exchange activity). The EC50 values (concentrations yielding half-maximal responses) for noradrenaline were lowered significantly by 1.7- to 3.9-fold in the blood from physically stressed fish. The enhanced adrenergic responsiveness of the rbcs appeared to be unrelated to changes in the initial steps of the beta-adrenergic signal transduction pathway leading to cyclic AMP production because physical stress was without effect on the magnitude or the dose-dependency of rbc cyclic AMP accumulation. To determine whether post-cyclic-AMP events were affected by physical stress, water and Na+ accumulation were measured in rbcs that had been incubated with the permeable cyclic AMP analogue 8-bromo cyclic AMP. The EC50 values for 8-bromo cyclic AMP were lowered by 1.6- to 1.7-fold in the blood from stressed fish. These experiments demonstrate that repeated physical stress significantly enhances the adrenergic responsiveness of the rainbow trout rbc, presumably by modifying the sensitivity of the Na+/H+ exchanger (or the steps immediately preceding exchanger activation) to cyclic AMP. The results are discussed with respect to the interrelationships between chronic and acute stress responses in fish.

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