Red Blood Cell Filtration Research Articles

Influence of cyclandelate on in vitro red blood cell deformability.

Using filtration and viscosity techniques, cyclandelate, some of its metabolites and flunarizine were evaluated to determine their ability to maintain human red blood cell (RBC) deformability. In filtration studies, RBC suspensions were metabolically depleted, which decreased the capacity of the cells to pass through narrow filter pores. In viscosity measurements performed with whole blood, metabolic depletion resulted in an increase of blood viscosity values. The results of these experiments appeared to indicate that cyclandelate, cyclandelate alcohol and flunarizine were approximately equipotent in maintaining RBC filtration and blood viscosity values. Cyclandelate acid appeared to be less active in both studies. By measuring the adenosine triphosphate content of red blood cells it has been shown that this activity is not due to an action on red blood cell energy metabolism. Finally, experiments conducted with the calcium chelator EGTA showed that the activity of cyclandelate was reduced in the absence of Ca++ ions. The results strengthen the hypothesis that cyclandelate maintains red cell deformability by inhibiting calcium entry through the red cell membrane.

Erythrocytes from ozone-exposed mice exhibit decreased deformability

Injury from short-term exposure to ozone (O 3) was detected by a simple test of red blood cell (RBC) filterability. This test measures changes in the ability of the RBC to deform—as occurs during passage through small capillaries. Male CD-1 mice were exposed to 1.0, 0.7, or 0.3 ppm O 3 for 4 hr, and blood samples were obtained by heart puncture. RBCs were suspended in Tris-HCl buffer, pH 7.4, containing 10 mg/dl glucose. After incubation in air for up to 6 hr, the time required for 2 ml RBC suspension to pass through a 3-μm-pore-size polycarbonate filter was determined. A significant increase in the 6-hr filtration time for O 3-exposed (1.0 ppm) mice over unexposed mice and a lack of protection by vitamin E were shown. The increases in RBC filtration times for O 3-exposed mice appeared to be dose related. Ozone exposure (1.0 ppm) caused a significant increase in the hematocrit of both vitamin E-deficient and -supplemented mice. Vitamin E supplementation appeared to partially prevent this increase in hematocrit. Measurement of lipid peroxidation by the thiobarbituric acid (TBA) test revealed no detectable levels of TBA-reactive material in RBC from O 3-exposed mice. These results suggest that measurement of RBC filterability may be feasible as a clinical test for short-term injury from exposure to oxidant gases.

A compartmental analysis of the splenic circulation in rat.

Isolated, acellular washout experiments of 125I-labeled bovine serum albumin (BSA) from control, anemic, and polycythemic rat spleens were used to develop a model of the splenic plasma circulation. The results indicated that the plasma circulation can be described adequately by two compartments. As in red blood cell (RBC) washouts [Am. J. Physiol. 239 (Heart Circ. Physiol. 8): H272-H277, 1980] the fast compartment represents intrasplenic vessels that bypass the red pulp, whereas the intermediate/slow compartment represents plasma flow through the red pulp (filter). The combined plasma and RBC parameters suggest the rat spleen is not an RBC reservoir and that splenic RBC filtration capacity decreases during polycythemia and anemia. The ratio of fast compartment to systemic hematocrit indicates hemodilution occurs, supporting the concept of plasma skimming. A small plasma holdup occurs in the red pulp of anemic and polycythemic spleens probably due to RBC congestion. This congestion, in turn, might be due to reticulocyte sequestration and/or erythropoiesis in anemic spleens and RBC sequestration and/or destruction in polycythemic spleens. There is plasma redistribution in polycythemic spleens possibly to meet the increased metabolic demand.

Intralymphatic introduction of radioactive colloids into the lymph nodes. Preliminary study.

With the possibility in mind that it might be desirable to convey certain materials for therapeutic purposes directly to lymph nodes, preliminary experiments have been carried out on the dog's hind leg. The behavior of a lymph node toward foreign particles injected directly into the lymph trunk has received very little study. Drinker, Field, and Ward (1934) observed efficient filtration of red blood cells and bacteria by a single popliteal node and by a regional lymphatic system in the dog (1). Walker (1950) injected yttrium hydroxy citrate colloids in a trunk afferent to the popliteal node of the rabbit and then measured filtration or retention by the popliteal and pelvic nodes (2). His experiments were based on single injections with very small (0.05 to 0.20 ml.) volumes of fluid, and the measurements of radioactivity were made on nodes dissected one to nine days after injection. The first node in the filtering system retained a major portion of the injected colloid; secondary or tertiary nodes usually ...