scholarly journals Adrenergic inhibition of carbon dioxide excretion by trout red blood cells in vitro is mediated by activation of Na+/H+ exchange

1991 ◽  
Vol 157 (1) ◽  
pp. 367-380
Author(s):  
S. F. Perry ◽  
C. M. Wood ◽  
S. Thomas ◽  
P. J. Walsh
Keyword(s):  
Carbon Dioxide ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Beta Adrenoceptor ◽  
Alpha Adrenoceptor ◽  
Adrenoceptor Antagonist ◽  
Exchange Inhibitor ◽  
Adrenoceptor Agonist ◽  
Co2 Excretion

We have used a sensitive new technique to assess the mechanism(s) of adrenergic inhibition of rainbow trout (Oncorhynchus mykiss) red blood cell (RBC) carbon dioxide excretion in vitro. The effect was only apparent using blood acidified to simulate metabolic acidosis. Red blood cell CO2 excretion was inhibited in a dose-dependent manner by physiologically relevant concentrations of noradrenaline (10–1000 nmol l-1) or adrenaline (100–1000 nmol l-1). The beta-adrenoceptor antagonist propranolol abolished the inhibitory effect of adrenaline, whereas the alpha-adrenoceptor antagonist phentolamine was without effect. The action of noradrenaline on RBC CO2 excretion was mimicked by the beta-adrenoceptor agonist isoproterenol, but not by the alpha-adrenoceptor agonist phenylephrine. Therefore, adrenergic inhibition of CO2 excretion is mediated by RBC beta-adrenoceptors, presumably of the beta 1 subtype. The Na+/H+ exchange inhibitor amiloride effectively blocked adrenergic stimulation of Na+/H+ exchange (as indicated from measurements of pHe and RBC pHi) and entirely prevented the inhibition of CO2 excretion. Noradrenaline significantly reduced the rate of CO2 excretion even in the presence of the Cl-/HCO3- exchange inhibitor SITS. Therefore, adrenergic inhibition of CO2 excretion is accomplished via activation of RBC Na+/H+ exchange rather than by a direct inhibition of Cl-/HCO3- exchange. The observed relationship between CO2 excretion rates and the RBC transmembrane pH difference (pHe-pHi) and the occurrence of the inhibition only at low pHe provide further evidence of the linkage with RBC Na+/H+ exchange. We suggest that adrenergic activation of RBC Na+/H+ exchange impedes CO2 excretion by causing a rise in intracellular HCO3- levels concurrent with a reduction of intracellular PCO2. The net result is a reduced gradient for HCO3- entry into the RBC in conjunction with a diminution of the outwardly directed PCO2 gradient. Thus, the rate of formation of CO2 from the dehydration of plasma HCO3- is reduced and, in turn, a portion of this CO2 is not excreted but recycled through the red blood cell.

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.

Atypical beta-adrenoceptor- (beta 3-adrenoceptor) mediated relaxation of canine isolated bronchial smooth muscle

1993 ◽  
Vol 74 (1) ◽  
pp. 297-302 ◽  
Author(s):  
J. Tamaoki ◽  
F. Yamauchi ◽  
A. Chiyotani ◽  
I. Yamawaki ◽  
S. Takeuchi ◽  
...  
Keyword(s):  
Smooth Muscle ◽  
Rank Order ◽  
Bronchial Smooth Muscle ◽  
Beta Adrenoceptors ◽  
Beta Adrenoceptor ◽  
Adrenoceptor Antagonist ◽  
Adrenoceptor Agonist ◽  
Relaxant Response ◽  
Brl 37344

To determine whether atypical beta-adrenoceptors (beta 3-adrenoceptors) exist in the airway smooth muscle, we studied isolated bronchial segments from dogs under isometric conditions in vitro. Addition of beta-adrenoceptor agonists produced a concentration-dependent relaxation of tissues precontracted with 10(-5) M acetylcholine, rank-order potency being isoproterenol (1) > or = salbutamol (0.95) > or = BRL 37344, a beta 3-selective adrenoceptor agonist (0.83) > norepinephrine (0.10). Under the condition that alpha- and beta 1-adrenoceptors had been blocked, the relaxant response to salbutamol was competitively antagonized by the beta 2-adrenoceptor antagonist ICI 118551 and the pA2 was 7.01 +/- 0.25 (SE), whereas the response to BRL 37344 was resistant, with an apparent pA2 of 5.66. However, cyanopindolol, an antagonist for atypical beta-adrenoceptors, antagonized the BRL-induced relaxation in a competitive manner, with a pA2 of 6.74 +/- 0.11. This pA2 was lower than that when salbutamol was used as an agonist (P < 0.05). Intracellular adenosine 3',5'-cyclic monophosphate (cAMP) levels were increased by BRL 37344 in a concentration-dependent fashion. These results suggest that beta 3-adrenoceptors may exist in canine bronchial smooth muscle and that the stimulation of this type of receptor causes a bronchodilation through a cAMP-dependent pathway.

scholarly journals Effect of burst swimming and adrenaline infusion on O2 consumption and CO2 excretion in rainbow trout, Salmo gairdneri

1987 ◽  
Vol 131 (1) ◽  
pp. 427-434
Author(s):  
J. F. Steffensen ◽  
B. L. Tufts ◽  
D. J. Randall
Keyword(s):  
Carbon Dioxide ◽  
Oxygen Consumption ◽  
Rainbow Trout ◽  
Blood Cell ◽  
Red Blood Cell ◽  
Respiratory Exchange Ratio ◽  
Salmo Gairdneri ◽  
Adrenaline Infusion ◽  
Burst Swimming ◽  
Co2 Excretion

1. Immediately following burst swimming, the oxygen consumption of rainbow trout increased by 71%, carbon dioxide excretion by 104% and the respiratory exchange ratio by 17%. 80 min after burst swimming all of these parameters had returned to levels which were not significantly different from control values. 2. Infusion of adrenaline into resting fish had no significant effect on oxygen consumption or carbon dioxide excretion and therefore there was no significant change in the respiratory exchange ratio. 3. This infusion of adrenaline caused a significant elevation in the red blood cell pH which was still present 80 min later. 4. The present results contrast with those of van den Thillart, Randall & Lin (1983), who demonstrated carbon dioxide retention after burst swimming. While it is possible that catecholamines may inhibit bicarbonate flux through the red blood cell, our experiments indicate that this inhibition would not result in detectable changes in carbon dioxide excretion or, therefore, in the respiratory exchange ratio.

Investigation of the Free and Total Thyroxine-binding Capacity of Plasma Proteins in Thyroid Disorders

1971 ◽  
Vol 10 (04) ◽  
pp. 299-304
Author(s):  
József Takó ◽  
János Fischer ◽  
Jusztina Juhász ◽  
Ilona Sztraka ◽  
István Kapus ◽  
...  
Keyword(s):  
Blood Cell ◽  
Thyroid Function ◽  
Oral Contraceptives ◽  
Red Blood Cell ◽  
Plasma Proteins ◽  
Binding Capacity ◽  
Thyroid Disorders ◽  
Thyroid Function Tests ◽  
Total Thyroxine

SummaryThe results of thyroid function tests have been compared with data on the thyroxine-binding capacity of plasma proteins in hyper-, hypo- and euthyroid cases, the latter including women taking oral contraceptives (Infecundin). It was found that there exists a significant correlation of exponential nature between the in vitro red blood cell 125I-triiodothyronine uptake (RCU) and the free thyroxine-binding capacity of the thyroxine-inding globulin (TBG).

Patents on Red Blood Cell Manufacturing In Vitro

2011 ◽  
Vol 1 (2) ◽  
pp. 173-181
Author(s):  
Laurence Guyonneau-Harmand ◽  
Luc Douay
Keyword(s):  
Blood Cell ◽  
Red Blood Cell ◽  
Cell Manufacturing

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.

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