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.

Effect of epinephrine on vascular space of gills and head of rainbow trout

1976 ◽  
Vol 230 (6) ◽  
pp. 1555-1560 ◽  
Author(s):  
JP Girard ◽  
P Payan
Keyword(s):  
Rainbow Trout ◽  
Human Serum Albumin ◽  
Serum Albumin ◽  
Human Serum ◽  
Flow Rate ◽  
Teleost Fish ◽  
Ringer Solution ◽  
Perfusion Rate ◽  
Vascular Space

The filling of the gills and head vascular space of a teleost fish was measured in vitro by perfusing an isolated head of a trout with a Ringer solution containing 131I-labeled human serum albumin. The presence of epinephrine in the Ringer solution significantly increased afferent (ventral aortic) flow rate and efferent (dorsal aorta) flow rate, whereas branchial venous system circulation was reduced. When perfused with an epinephrine-free Ringer, the branchial vascular space appears 5-6 times greater than the head vascular space (per 100 g of tissue). Epinephrine, 10(-5) M, in the Ringer solution significantly decreased the branchial vascular space without modifying that of the head. The increase in perfusion rate and decrease in branchial vascular space due to the epinephrine can only be interpreted by taking into account a branchial nonlamellar compartment of a considerable volume.

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.

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.

Scanning Electron Microscopy of the Red Pulp of the Spleen

1971 ◽  
Vol 29 ◽  
pp. 496-497
Author(s):  
Masayuki Miyoshi
Keyword(s):  
Electron Microscope ◽  
Ringer Solution ◽  
Conclusive Evidence ◽  
Sinus Wall ◽  
Transmission Electron ◽  
Type 3 ◽  
Cytoplasmic Processes ◽  
Splenic Red Pulp ◽  
Scanning Electron ◽  
Red Pulp

In spite of various attempts, conclusive evidence to explain blood passage in the splenic red pulp does not seem to have been presented. Scanning electron microscope (SEM) observations on the rabbit spleen, originally performed by us, revealed that the sinus was lined by a perforated lattice composed of longitudinally extended rod cells and transverse cytoplasmic processes, and that perforations in the lattice were continuous to the spaces among the stellate reticulum cells of the cord. In the present study the observation was extended to the dog and rat spleens, in which the cord is more developed than in the rabbit in order to clarify the possible differences in the fine structure of the sinus wall. An attempt was also made to examine the development and distribution of macrophage in the blood passage of the red pulp.Spleens were washed and fixed by perfusion with Ringer solution and then with buffered glutaraldehyde. Small tissue cubes were dehydrated with acetone, dried in air and heated with gold. Observations were made by a JEOL SEM Type-3. One air dried tissue cube was cut into small pieces and post fixed with buffered OsO4 for examination under the transmission electron microscope (TEM).

Myocardial CO2 buffering: role of transmembrane transport of H+ or HCO3-ions

1976 ◽  
Vol 230 (4) ◽  
pp. 1037-1041 ◽  
Author(s):  
DR Strome ◽  
RL Clancy ◽  
NC Gonzalez
Keyword(s):  
Small Volume ◽  
Coronary Circulation ◽  
Myocardial Cell ◽  
Ringer Solution ◽  
Red Cells ◽  
Transmembrane Transport ◽  
High Degree

Isolated rabbit hearts were perfused with rabbit red cells suspended in Ringer solution. A small volume of perfusate was recirculated for 10 min at Pco2 of 33.4 +/- 0.9 or 150.8 +/- 7.5 mmHg. Hypercapnia resulted in an increase in perfusate HCO3- concentration that was smaller than that observed when isolated perfusate was equilibrated in vitro with the same CO2 tensions (delta HCO-3e = 1.6 mM, P less than 0.01). This difference is consistent with a net movement of HCO3- into or H+ out of the mycardial cell, and cannot be accounted for by dilution of HCO3- in the myocardial interstitium. Recirculation of perfusate through the coronary circulation at normal Pco2 for two consecutive 10-min periods was not followed by changes in perfusate HCO3- concentration. A high degree of correlation (r = 0.81) was observed between intracellular HCO-3e concentration and the corresponding delta HCO-3e in individual experiments. The results suggest that transmembrane exchange of H+ or HCO3- is a buffer mechanism for CO2 in the myocardial cell.

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.

Resetting of tubuloglomerular feedback: evidence for a humoral factor in tubular fluid

1984 ◽  
Vol 246 (4) ◽  
pp. F495-F500 ◽  
Author(s):  
D. A. Haberle ◽  
J. M. Davis
Keyword(s):  
Flow Rate ◽  
Juxtaglomerular Apparatus ◽  
Ringer Solution ◽  
Humoral Factor ◽  
Inhibitory Factor ◽  
Tubuloglomerular Feedback ◽  
Fluid Composition ◽  
Similar Magnitude ◽  
Feedback Responses

Experiments were performed on chronically salt-loaded rats to determine whether resetting of tubuloglomerular feedback is caused by changes in the sensitivity of the juxtaglomerular apparatus itself or by changes of tubular fluid composition. The feedback response was quantified in both salt-loaded and salt-deplete rats by measuring early proximal flow rate (EPF) during loop perfusion at 40, 10, and 0 nl/min using tubular fluid harvested from both groups and with Ringer solution. In salt-loaded rats endogenous tubular fluid produced only a small feedback response (EPF40-0 = 1.9 +/- 1.5 nl/min), whereas exogenous tubular fluid from salt-deplete rats or Ringer solution produced normal feedback responses (EPF40-0 = 15.4 +/- 2.0 and 10.6 +/- 1.7 nl/min, respectively). In salt-deplete rats, endogenous tubular fluid and Ringer solution produced feedback responses of similar magnitude (EPF40-0 = 14.2 +/- 1.8 and 13.0 +/- 2.0 nl/min, respectively) but exogenous tubular fluid from salt-loaded rats elicited only a small feedback response (EPF40-0 = 1.5 +/- 1.6 nl/min), indistinguishable from that seen in salt-loaded rats with endogenous tubular fluid. It is concluded that an inhibitory factor in the tubular fluid of chronically salt-loaded rats causes a reduction in tubuloglomerular feedback response.

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.

Effects of pH, ionic strength, dissolved organic matter, and flow rate on the co-transport of MS2 bacteriophages with kaolinite in gravel aquifer media

2010 ◽  
Vol 44 (4) ◽  
pp. 1255-1269 ◽  
Author(s):  
Gillian E. Walshe ◽  
Liping Pang ◽  
Markus Flury ◽  
Murray E. Close ◽  
Mark Flintoft
Keyword(s):  
Organic Matter ◽  
Ionic Strength ◽  
Dissolved Organic Matter ◽  
Flow Rate ◽  
Effects Of Ph ◽  
Gravel Aquifer
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