Release of red cells from the slowly-exchanging splenic pool after noradrenaline administration

1976 ◽  
Vol 54 (4) ◽  
pp. 477-484 ◽  
Author(s):  
H. B. Geiger ◽  
S. H. Song ◽  
A. C. Groom
Keyword(s):  
Time Course ◽  
Cell Concentration ◽  
Splenic Vein ◽  
Ringer Solution ◽  
Red Cells ◽  
Red Cell ◽  
Outflow Rate ◽  
Abnormal Cells ◽  
Noradrenaline Administration ◽  
Red Pulp

Isolated, denervated, cat spleens were perfused at constant flow with modified Ringer solution. Perfusion pressure, outflow rate, and outflow red cell concentration were measured against time. After splenic perfusion by 500 ml solution the cell washout curve became a single exponential function, indicating that only cells from the most slowly exchanging red cell compartment remained (these are immature and abnormal cells which adhere to the fine structures of the red pulp). Splenic contraction was induced by injection of 5 μg noradrenaline into the inflow after perfusion by 600 and 1000 ml of fluid, respectively; outflow cell concentration rose 17-fold before returning to baseline value and 32% of red cells in the spleen were expelled. The time course of changes in cell concentration was similar in shape but delayed with respect to that of outflow rate. The transit time of the cells from the site of release to the splenic vein must have exceeded 40 s, which is consistent only with release from the red pulp. Furthermore, at the peak of the cell concentration curve the mean reticulocyte count was 37.8%. Thus immature and abnormal red cells, which comprise the slowly-exchanging compartment, are indeed released from the spleen during contraction.

pH environmental of red cells in the spleen

1976 ◽  
Vol 231 (6) ◽  
pp. 1672-1678 ◽  
Author(s):  
MJ Levesque ◽  
AC Groom
Keyword(s):  
Splenic Tissue ◽  
Red Cells ◽  
Red Cell ◽  
Cat Spleen ◽  
Flow Through ◽  
Red Pulp ◽  
Reduced Flow

Intrasplenic pH in vivo was deduced from measurements on blood drained from cat spleen during contraction with the inflow occluded. The pH of blood in the red pulp is normally 7.20, but stasis or reduced flow through the pulp causes pH to fall toward 6.8. The splenic pulp contains blood of high hematocrit. To evaluate the role of buffering by the red cells themselves, intrasplenic p/ in red cell-free spleens was, therefore, estimated atering and leaving the spleen during red cell washout. At inflow pH less than 6.8 the outflow pH was raised, at inflow pH = 6.8 there was no change, b,t at inflow pH greater than 6.8 the outflow pH was lowered. These results indicate that the pH environment of red cells in the spleen results indicate that the pH environment of red cells in the spleen results from the interplay of two separate factors: i) pH-determining elements of the splenic tissue that buffer at 6.8, and ii) buffering provided by red cells passing through the pulp.

Sequestration and Possible Maturation of Reticulocytes in the Normal Spleen

1972 ◽  
Vol 50 (5) ◽  
pp. 400-406 ◽  
Author(s):  
S. H. Song ◽  
A. C. Groom
Keyword(s):  
Bone Marrow ◽  
Ringer Solution ◽  
Red Cell ◽  
Cell Compartment ◽  
Daily Production ◽  
Physiological Conditions ◽  
Cellular Density ◽  
Cellular Volume ◽  
Normal Spleen ◽  
Red Pulp

The presence, in the feline spleen, of a slowly exchanging red cell 'compartment' ([Formula: see text] 54 min) has been demonstrated previously. These red cells adhere to reticulum cells and sinus walls in the red pulp and have been shown to be larger in cellular volume and lighter in cellular density than the rest. This suggested that they might be younger cells and we have reported briefly that they contain a high proportion of reticulocytes. Using supravital stains we have measured the percentage of reticulocytes in the outflow from isolated spleens of cats and dogs, perfused with oxygenated Ringer solution. Reticulocyte counts increased from 0.4% to 99% as the perfusion progressed. The results show that the slow compartment consists entirely of reticulocytes. The ratio of reticulocytes to rubricytes in the spleen was found to be 75:1. Therefore the reticulocytes were not produced in the spleen but were accumulated from the circulating blood. The total number of reticulocytes so stored is 1.2 × 1010 cells, equivalent to 1.5 times the daily production in the whole animal. From these data we conclude that reticulocytes released from the bone marrow under physiological conditions are sequestered and matured in the spleen.

scholarly journals Effect of RBCs on the activation of human complement by heparin- protamine complexes

Blood ◽  
1988 ◽  
Vol 71 (1) ◽  
pp. 36-40 ◽  
Author(s):  
KA Shastri ◽  
MJ Phillips ◽  
S Raza ◽  
GL Logue ◽  
PK Rustagi
Keyword(s):  
Monoclonal Antibody ◽  
Human Serum ◽  
Complement Activation ◽  
Cell Concentration ◽  
Fluid Phase ◽  
Red Cells ◽  
Red Cell ◽  
Human Complement ◽  
Red Cell Membranes ◽  
Classic Pathway

Abstract Complement activation on red cells by heparin-protamine complexes was studied by using whole human serum. C3 bound to red cells was measured by radiolabeled monoclonal antibody to C3, and fluid-phase C5a was determined by radioimmunoassay. Heparin and protamine in clinically relevant concentrations caused the binding of C3 to red cell membranes, and the measurement of C3 binding provided a sensitive indicator of complement activation produced by these complexes. Complement activation by these reagents occurred at concentration ratios of protamine and heparin at which protamine neutralized the anticoagulant effect of heparin. Heparin-protamine complexes appeared to bind to red cells and produce complement activation by the classic pathway. C5a generation with heparin-protamine complexes in serum was greatly enhanced in the presence of red cells and increased with increasing red cell concentration. This enhancement of complement activation in the presence of red cells was also seen as measured by depletion of available C3 hemolytic complement units in the fluid phase. Thus red cells seem to play an important role in activation of complement by heparin-protamine complexes.

Washout kinetics of red cells and plasma from the spleen

1976 ◽  
Vol 231 (6) ◽  
pp. 1665-1671 ◽  
Author(s):  
MJ Levesque ◽  
AC Groom
Keyword(s):  
Ringer Solution ◽  
Red Cell ◽  
Compartment Analysis ◽  
Vascular Space ◽  
Cell Components ◽  
Arterial Inflow ◽  
Fine Structures ◽  
Immature Cells ◽  
Kinetics Of ◽  
Red Pulp

Radioiodinated (125I) serum albumin was injected inttravenously in cats and allowed to equilibrate in the circulation. Red cell and plasma washout from the isolated spleens were enrom the isolated spleens were then compared during perfusion with oxygenated Ringer solution, the respective concentrations in the outflow being measured by celloscope and scintillation counters. Washout kinetics yielded three exponential components for cells (perfusate volumes for 50% washout (V1/2) being 0.067, 4.70, and 97 ml/g spleen) but only two for plasm (V1/2, 0.14 and 2.40 ml/g). There is no plasma counterpart to the slowly released cells, i.e., they do not represent a separate vascular space. This is an accord with a previous view that these are immature cells, delayed through adherence to fine structures of the red pulp. Compartment analysis indicates that the plasma and two remaining cell components represent washout from two separate vascular spaces, containing 0.09 ml/g blood at arterial hematocrit 37% and 0.42 ml/g blood at hematocrit 75%, perfused by 0.9 and 0.1 of the arterial inflow respectively. Evidence suggests these spaces are i) blood vessels, and ii) red pulp.

scholarly journals The Effect of Enhanced Fibrinolytic Activity on the Red Cell Membrane Transport

1977 ◽  
Author(s):  
S.B. Ulutin ◽  
N. B. Emekli ◽  
T. U. Yardimici
Keyword(s):  
Active Transport ◽  
Fibrinolytic Activity ◽  
Time Course ◽  
Degradation Products ◽  
Human Subjects ◽  
Red Cells ◽  
Fibrinolytic System ◽  
Red Cell ◽  
Red Cell Membrane ◽  
Before And After

In dogs and in human subjects, using hepatic vein catheterization before and after the activation of the fibrinolytic system, the blood samples were obtained and the red cell amino acid transport was investigated. The time course accumulation of radioactive histidine in isolated red cells was followed together with the measurements of the fibrinolytic activity.A decrease in the active transport of histidine was observed in the red cells after the stimulation of the fibrinolytic system. Also a correlation between the decrease of active transport and the increase of fibrin-fibrinogen degradation products was seen.

The Distribution of Red Cells in the Spleen

1971 ◽  
Vol 49 (8) ◽  
pp. 734-743 ◽  
Author(s):  
S. H. Song ◽  
A. C. Groom
Keyword(s):  
Inclusion Bodies ◽  
Ringer Solution ◽  
Red Cells ◽  
Compartment System ◽  
Cell Counts ◽  
Sinus Wall ◽  
Free Cells ◽  
Abnormal Cells ◽  
Vascular Channels ◽  
Kinetics Of

Kinetics of red cell washout, when isolated cat spleens are perfused with Ringer solution, show that the spleen corresponds to a three-compartment system. To determine whether or not there exist morphological counterparts to these compartments we examined microscopic sections from 16 spleens perfused by different volumes of Ringer solution. Red cells could be divided into three groups: (1) free cells in vascular channels and sinuses, (2) cells adhering to reticulum cells or sinus endothelium, and (3) cells in the cytoplasm of macrophages. When 50 ml were perfused no free cells were seen in vascular channels. After 600 ml few free cells remained in the sinuses. Thereafter the number of cells adhering to the sinus wall decreased gradually and cell counts agreed with predictions from the washout curve. We conclude that the compartments of our model (fast, intermediate, and slow) represent, respectively, free cells in vascular channels, free cells within sinuses, and cells adhering to sinus walls. The only cells trapped irreversibly are the very few found in the cytoplasm of macrophages. It is suggested that the slow compartment represents red cells in a pre-phagocytosed stage, e.g. aged cells, abnormal cells containing inclusion bodies, and possibly, reticulocytes in the process of maturation.

scholarly journals Heinz Body Anemia: An Ultrastructural Study. II. Red Cell Sequestration and Destruction

Blood ◽  
1965 ◽  
Vol 26 (4) ◽  
pp. 433-448 ◽  
Author(s):  
RICHARD A. RIFKIND
Keyword(s):  
Electron Microscope ◽  
Red Cells ◽  
Severely Injured ◽  
Red Cell ◽  
Intravascular Hemolysis ◽  
Heinz Bodies ◽  
Intracellular Digestion ◽  
Splenic Red Pulp ◽  
Selective Accumulation ◽  
Red Pulp

Abstract This study reports electron microscope observations on the process of red cell sequestration and destruction in the spleen and liver of the phenylhydrazine-treated rabbit. Damaged red cells are recognized by virtue of their Heinz bodies, a morphologic manifestation of the oxidative injury which they have sustained. Sequestration, in the spleen, involves the selective accumulation of damaged cells within the vascular spaces of the Billroth cords. Erythrophagocytosis and the intracellular digestion of red cells follows sequestration. More severely injured cells may undergo intravascular hemolysis within the splenic red pulp. In the liver, however, no evidence for the intravascular sequestration of injured red cells is observed. Damaged cells are removed directly from the sinusoidal blood by erythrophagocytosis. The selectivity of spleen and liver for red cells subjected to different degrees of injury is discussed in terms of the observed differences in the vascular architecture of the two organs.

N.m.r. studies of red cells

1980 ◽  
Vol 289 (1037) ◽  
pp. 395-406 ◽  
Keyword(s):  
Small Molecules ◽  
Time Course ◽  
Pulse Sequence ◽  
Spin Echo ◽  
Cell System ◽  
Red Cells ◽  
Red Cell ◽  
Lactate And Pyruvate ◽  
Echo Pulse ◽  
2,3 Dpg

Recent n.m.r. studies of intact red cells are described. With 1 H n.m.r. the normal high resolution spectra of red cells, even at high fields, are relatively uninformative because the very large number of resonances from the cells merge into a broad envelope. If a simple 90- τ - 180° spin echo pulse sequence is used, however, many resonances can be resolved. These include signals from haemoglobin histidines, glutathione, lactate and pyruvate. 13 C and 31 P signals have also been seen with a spectrometer converted to observe these nuclei essentially simultaneously. N.m.r. is well suited to monitor the time course of events after a perturbation of the cell system. Lactate increase, glutathione recovery after oxidation and alkylation of glutathione by iodoacetate can all be observed directly in red cell suspensions by means of 1 H spin echo n.m.r. This method has also been used to measure isotope exchange ( 1 H - 2 H) of lactate and of pyruvate at both the C-3 and the C-2 positions, and some of these exchange rates can be interpreted in terms of the activity of specific enzymes in the cells. 1 H spin echo n.m.r. has also been used to obtain information about the transport rates of small molecules into cells. By means of the 13 C / 31 P spectrometer and [ 13 C-1] glucose, the 13 C enrichment of 2,3-diphosphoglycerate (2,3-DPG) can be monitored at the same time as the levels of 2,3-DPG, ATP and inorganic phosphate are observed by 31 P n.m.r.

Effects of pH and flow rate on the release of 'bound' red cells from the splenic pulp

1978 ◽  
Vol 56 (2) ◽  
pp. 260-268 ◽  
Author(s):  
M. J. Levesque ◽  
A. C. Groom
Keyword(s):  
Flow Rate ◽  
Slow Component ◽  
Bound State ◽  
Ringer Solution ◽  
Red Cells ◽  
Fluid Shear ◽  
Perfusion Rate ◽  
Effects Of Ph ◽  
Fine Structures ◽  
Red Pulp

On perfusion of isolated, denervated spleens with Ringer solution, immature and abnormal red cells are released into the venous outflow much more slowly than normal mature cells, being delayed through adherence to fine structures of the red pulp (Am. J. Physiol. 231, 1665–1671 (1976)). Evidence suggested that the rate at which such cells are released from the 'bound' state might depend on local pH and fluid shear rate within the pulp. Therefore, the rate of washout for this slow component of red cells, from cat spleens, was measured as a function of pH and flow rate of the perfusate. The volume of solution (V½) for 50% washout of 'bound' cells decreased as pH was lowered from 7.8 to 6.6, especially (from 97 to 18 ml/g) between 7.4 and 6.6. The percentage total red cell outflow thus represented rose from 0.06 to 0.5 as pH fell from 7.8 to 6.6. At a high perfusion rate (14–16 ml/min) the V½ value was only one-half that prevailing at a lower rate (4–6 ml/min), and the percentage flow of 'bound' red cells was more than three times greater. Both acidic pH and augmented blood flow thus assist release of adherent red cells from the splenic pulp.

scholarly journals An Ultrastructural Study of the Red Pulp of the Spleen in Malaria

Blood ◽  
1973 ◽  
Vol 41 (2) ◽  
pp. 207-218 ◽  
Author(s):  
B. Schnitzer ◽  
T. M. Sodeman ◽  
M. L. Mead ◽  
P. G. Contacos
Keyword(s):  
Rhesus Monkey ◽  
Ultrastructural Study ◽  
Plasmodium Knowlesi ◽  
Red Cells ◽  
Red Cell ◽  
Malaria Parasites ◽  
Red Pulp

Abstract An ultrastructural study was undertaken of the spleen of a rhesus monkey infected with Plasmodium knowlesi to determine whether the spleen is able to pit malaria parasites from red cells. It was found that in the spleen parasitized cells are: (1) phagocytized in toto by cordal macrophages, (2) pitted of parasites, and (3) hemolyzed in the splenic microvasculature. Phagocytosis of the entire parasitized red cell appears to occur most frequently of the three mechanisms and probably accounts for most of the anemia. Pitting of parasitized red cells may account in part for the hemolysis in excess of the number of parasitized red cells seen in malaria. The red cells that have had their parasites removed would become spherocytic and hence, would be more susceptible to removal from the circulation during subsequent passages through the spleen.

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