Relationship between the Maximum Velocity and Sodium Affinity of the Erythrocyte Sodium Pump and its Rate Constant in Blood

1990 ◽  
Vol 79 (6) ◽  
pp. 625-630 ◽  
Author(s):  
T. H. Thomas ◽  
S. MacPhail ◽  
V. Mott ◽  
R. Wilkinson

1. Young and mature erythrocytes from 15 normal subjects were used to compare the sodium pump rate constant measured in whole blood with the more definitive sodium affinity constant and maximum velocity of the sodium pump measured in artificial media using sodium-loaded cells. 2. Similar values were obtained from both erythrocyte fractions for the sodium affinity constant and maximum velocity and also by using two different plots. The median error in the estimate of individual sodium affinity constants and maximum velocities from regression analysis was about 20% and the precision was not improved by combining the data points for the two erythrocyte fractions. 3. The rate constant in whole blood was closely related to the sodium affinity constant and maximum velocity of the sodium pump (r = 0.75), suggesting that it was a reasonable overall assessment of available sodium pump activity. 4. Differences in the rate constant between subjects were due to differences in both the maximum velocity and sodium affinity constant of the sodium pump so that the rate constant could not be used as a guide to the underlying sodium pump physiology.

1990 ◽  
Vol 79 (6) ◽  
pp. 631-638 ◽  
Author(s):  
S. MacPhail ◽  
T. H. Thomas ◽  
R. Wilkinson ◽  
J. M. Davison ◽  
W. Dunlop

1. Normotensive primigravid pregnant women were studied longitudinally during pregnancy and 20 weeks after delivery. 2. Erythrocyte sodium content, ouabain-sensitive sodium flux and sodium pump rate constant were measured in whole blood, and the maximum velocity and sodium affinity of the sodium pump were measured in vitro. 3. Erythrocyte sodium content decreased and the sodium pump rate constant increased up to 26 weeks gestation. The increase in rate constant was due to an increase in the affinity of the sodium pump for sodium up to 20 weeks gestation. After 20 weeks gestation there was an increase in maximum velocity and a decrease in sodium affinity of the sodium pump but no further change in the sodium pump rate constant. 4. At 14 weeks gestation the sodium pump rate constant was correlated with both the maximum velocity and sodium affinity constant. After this time the relationship was much more variable and there was no correlation with the sodium affinity constant. The comparison of measurements of the sodium pump in whole blood and in vitro gave no evidence of sodium pump inhibition. 5. The erythrocyte sodium pump changed throughout gestation with different components to the change, but, overall, available sodium pump activity in blood increased and sodium content decreased.


1990 ◽  
Vol 79 (4) ◽  
pp. 365-369 ◽  
Author(s):  
P. A. Rutherford ◽  
T. H. Thomas ◽  
R. Wilkinson

1. Sodium-lithium countertransport activity in a standard assay, its sodium affinity constant and maximum velocity were measured in erythrocytes from normal subjects and from essential hypertensive patients with and without a family history of hypertension. 2. In normal subjects the sodium concentration used in the standard assay was similar to the sodium affinity constant so that the activity measured in this assay was less than the maximum velocity. 3. In patients with essential hypertension and a positive family history, 33% had a sodium-lithium countertransport activity greater than the upper limit of the normal control range (0.4 mmol of Li+ h−1 l−1 of cells). 4. The reason for the raised sodium-lithium countertransport activity was an increased sodium affinity (lower sodium affinity constant) at the outside ion-binding site. 5. Of the patients with essential hypertension and a positive family history but sodium-lithium countertransport activity within the normal range in the standard assay, 30% also had a low sodium affinity constant. 6. A low sodium affinity constant at the outside site of the sodium-lithium countertransporter may be a more specific indicator for a group of patients with inherited hypertension than the standard sodium-lithium countertransport activity assay.


1983 ◽  
Vol 65 (3) ◽  
pp. 66P-66P
Author(s):  
P.L. Weissberg ◽  
M.J. West ◽  
M.R. Wilkins

1997 ◽  
Vol 78 (02) ◽  
pp. 855-858 ◽  
Author(s):  
Armando Tripodi ◽  
Veena Chantarangkul ◽  
Marigrazia Clerici ◽  
Barbara Negri ◽  
Pier Mannuccio Mannucci

SummaryA key issue for the reliable use of new devices for the laboratory control of oral anticoagulant therapy with the INR is their conformity to the calibration model. In the past, their adequacy has mostly been assessed empirically without reference to the calibration model and the use of International Reference Preparations (IRP) for thromboplastin. In this study we reviewed the requirements to be fulfilled and applied them to the calibration of a new near-patient testing device (TAS, Cardiovascular Diagnostics) which uses thromboplastin-containing test cards for determination of the INR. On each of 10 working days citrat- ed whole blood and plasma samples were obtained from 2 healthy subjects and 6 patients on oral anticoagulants. PT testing on whole blood and plasma was done with the TAS and parallel testing for plasma by the manual technique with the IRP CRM 149S. Conformity to the calibration model was judged satisfactory if the following requirements were met: (i) there was a linear relationship between paired log-PTs (TAS vs CRM 149S); (ii) the regression line drawn through patients data points, passed through those of normals; (iii) the precision of the calibration expressed as the CV of the slope was <3%. A good linear relationship was observed for calibration plots for plasma and whole blood (r = 0.98). Regression lines drawn through patients data points, passed through those of normals. The CVs of the slope were in both cases 2.2% and the ISIs were 0.965 and 1.000 for whole blood and plasma. In conclusion, our study shows that near-patient testing devices can be considered reliable tools to measure INR in patients on oral anticoagulants and provides guidelines for their evaluation.


1974 ◽  
Vol 125 (588) ◽  
pp. 459-460 ◽  
Author(s):  
J. Damas Mora ◽  
D. Vlissides ◽  
F. A. Jenner

In Orthomolecular Psychiatry; Treatment of Schizophrenia, edited by David Hawkins and Linus Pauling (1973), Beebe and Wendel (pp. 278–302) report a high correlation coefficient of r = 0.99 (which we calculate gives N = 42, p very much lower than 0.001) between whole blood glucose and adenosine triphosphate (ATP). This relationship they claim is no longer maintained in schizophrenics with anxiety, r = 0.16 (N = 62, p > 0.1). Erban and Hanzlicek (1966), Hansen (1972) and Hansen and Dimitrakoudi (1974) have suggested a possible significance of whole blood ATP in psychoses, and Naylor, Dick, Dick, Le Poidevin and Whyte (1973) have implicated red cell Na/K ATPases. The mechanisms involved in controlling blood ATP seemed therefore worthy of study especially if they are so dependent on glucose.


1987 ◽  
Author(s):  
L Mannucci ◽  
R Redaelli ◽  
E Tremoll

To evaluate the effects of blood cells on the response of platelets to aggregating agents using whole blood impedance aggregometer, studies were carried out on whole blood (WB) of normal subjects and of patients with: polycythemia vera (PV), iatrogenic anemia (IA), primary thrombocytosis (PT), idiopathic thrombotic purpura (ITP), myeloid chronic leukemia (MCL), iatrogenic leukopenia (IL). The in vitro effects of red blood cells (RBC) and of white blood cells (WBC) on platelet rich plasma (PRP) aggregation were also evaluated. WB, PRP, WBC and RBC were prepared by conventional methods. Aggregation was performed using the impedance aggregometer (mod. 540, Chrono Log Corp). In normal subjects the concentration of collagen giving 50 % aggregation (AC50 ) found in PRP did not differ from that of WB, indicating that hematocrit values within the normal range did not appreciably affect platelet aggregation. The results obtained in WB of patients are summarized in the table: In vitro data showed that aggregation in prp in wb of normal subjects was related to the number of platelets present in the sample. RBC added to PRP significant reduced aggregation only when the RBC number was greater than 4.101 cells. No effect of WBC on collagen induced aggregation of PRP was observed, whereas significant inhibition was detected after ADP. It is concluded that the aggregation evaluated in WB with impedance method is dependent on the platelet number. Also, in vitro data and studies in WB of patients indicate that aggregation is significantly affected by the presence of cells other than platelets only in conditions of changes of the ratio between platelets and leukocytes and/or red cells.


Blood ◽  
1978 ◽  
Vol 51 (5) ◽  
pp. 789-798 ◽  
Author(s):  
TH Price ◽  
DC Dale

Abstract The kinetics in blood of autologous neutrophils collected by phlebotomy, filtration leukapheresis (FL), or intermittent-flow centrifugation (IFC), labeled with 32P-diisopropylfluorophosphate, and stored at 4 degrees C for up to 2 days were measured in 41 normal subjects. Mean initial recovery for unstored IFC cells was 34.0%, compared to 7.9% for unstored FL cells. Blood half-lives were 4.1 and 2.7 hr for unstored IFC and FL cells, respectively. With neutrophils collected by phlebotomy and stored in whole blood for 1–2 days, posttransfusion recoveries and blood half-times were significantly decreased. Storage of both IFC and FL preparations resulted in only moderate kinetic abnormalities in comparison to the unstored cells. These studies indicate that the ability of unstored IFC cells to circulate is basically normal, whereas that of unstored FL cells is significantly impaired. The data further suggest that these neutrophil concentrates might be stored for 1–2 days prior to transfusion.


2008 ◽  
Vol 1 ◽  
pp. CMBD.S507 ◽  
Author(s):  
Masato Mitsuhashi ◽  
Katsuya Endo ◽  
Kazuhiko Obara ◽  
Hiroshi Izutsu ◽  
Taishi Ishida ◽  
...  

Apoptosis was induced in heparinized human whole blood by 3 different ways (radiation, bleomycin, or etoposide), and various mRNA were quantified using the method we reported (Clin. Chem. 2006; 52:634-642). We found that cyclin-dependent kinase inhibitor 1A (p21) and p53 upregulated modulator of apoptosis (PUMA) were the most sensitive and universal mRNA markers of apoptosis in leukocytes. In order to define positive and negative responses, a synthetic RNA was spiked into the lysis buffer and the fold increase was calculated. As a result, 837/880 (95.1%) of data points stayed between 0.75 and 1.5 fold increase, and 874/880 (99.3%) were within 0.5-2.0 fold increase. When blood samples from 40 healthy adults were stimulated with 22 different drugs, more than 75% of the samples responded to bleomycin (1 μM), idarubicin (2 μM), vincristine (1 μM), daunorubicin (2 μM), cytarabine (10 μM), to induce p21 and/or PUMA mRNA, and approximately 25% showed no induction. Significant correlation was found between p21 and PUMA mRNA responses, and between daunorubicin and cytarabine, idarubicin, and vincristine for both p21 and PUMA. The quantification of drug-induced mRNA in whole blood will be considered as ex vivo, and is a suitable platform for biomarker screening as well as a model system for drug sensitivity tests in future.


1979 ◽  
Vol 25 (10) ◽  
pp. 1787-1790 ◽  
Author(s):  
C D Tollinger ◽  
H J Vreman ◽  
M W Weiner

Abstract We measured acetate concentrations in whole blood, serum, and plasma by a modification of a previously described method involving vacuum distillation and gas chromatography. The mean acetate concentration of fresh venous plasma from 27 normal subjects was 51 +/- 5 mumol/L (95% confidence limits ranged from 0 to 103 mumol/L). The acetate concentrations of serum and plasma incubated for 2 h at either 4 degrees C or 27 degrees C were the same. The acetate concentration of whole blood incubated at 27 degrees C was significantly greater than that of blood incubated at 4 degrees C. This change may have resulted from the production of acetate by erythrocytes or from the hydrolysis of acetate esters. Storage of plasma at -20 degrees C for 24 h significantly increased acetate concentrations from 26 +/- 6 mumol/L to 63 +/- 4 mumol/L. After the subjects consumed a standard breakfast, venous plasma acetate concentrations increased from 58 to 97 mumol/L at 30 min. Acetate concentrations in arterial plasma exceeded those in venous plasma. Plasma acetate concentrations were not significantly altered in patients with malignancy or diabetes mellitus, but severe liver disease and severe acidosis were both associated with increased acetate concentrations. These preliminary observations suggest that plasma acetate concentrations may be altered in several disease states.


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