Studies on sequestration of neuraminidase-treated red blood cells

1988 ◽  
Vol 254 (6) ◽  
pp. H1167-H1171 ◽  
Author(s):  
S. Simchon ◽  
K. M. Jan ◽  
S. Chien
Keyword(s):  
Blood Flow ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Regional Blood Flow ◽  
Femoral Vein ◽  
Control Period ◽  
Flow Ratio ◽  
Blood Flows ◽  
Regional Blood Flows ◽  
Blood Flow Ratio

The effects of reduction in the surface charge of red blood cells (RBCs) on regional blood flow and RBC distribution were studied in rats anesthetized with pentobarbital sodium. RBCs were treated with neuraminidase to reduce their electrophoretic mobility by 56%. Normal and neuraminidase-treated RBCs labeled with 51Cr or 111In were injected into a femoral vein while an equal volume of blood was simultaneously withdrawn from a femoral artery. More than 70% of the neuraminidase-treated RBCs injected disappeared from the circulating blood in 30 min compared with less than 2% of normal RBCs. The relative distributions of neuraminidase-treated RBCs to normal RBCs, as determined from radioactivity counting, were significantly greater than 1 in the spleen (5.65 +/- 0.97, mean +/- SD), the liver (2.84 +/- 0.21), the lung (1.48 +/- 0.31), and the kidney (1.49 +/- 0.27), indicating a preferential trapping of neuraminidase-treated RBCs in these regions. This ratio was approximately 1 in all other organs. Regional blood flows in tissues were determined with 15-micron microspheres in the control period and after the infusion of neuraminidase-treated RBCs (experimental). Experimental-to-control blood flow ratios were 0.40 +/- 0.05 in the spleen, 0.66 +/- 0.06 in the liver, 0.78 +/- 0.03 in the lung, and 0.78 +/- 0.09 in the kidneys; this ratio was approximately 1 in all other organs. An experimental-to-control blood flow ratio less than 1 indicates a reduction in blood flow; this occurred in the same organs as those with trapping of neuraminidase-treated RBCs.(ABSTRACT TRUNCATED AT 250 WORDS)

Influence of reduced red cell deformability on regional blood flow

1987 ◽  
Vol 253 (4) ◽  
pp. H898-H903 ◽  
Author(s):  
S. Simchon ◽  
K. M. Jan ◽  
S. Chien
Keyword(s):  
Blood Flow ◽  
Regional Blood Flow ◽  
Femoral Vein ◽  
Control Period ◽  
Significant Degree ◽  
Relative Distribution ◽  
Cell Deformability ◽  
Red Cell Deformability ◽  
Diluted Solution ◽  
Regional Blood Flows

The effects of a reduction in red blood cell (RBC) deformability on regional blood flow and RBC distribution were studied in rats anesthetized with pentobarbital sodium. RBCs were subjected to minimum hardening by incubation in a very diluted solution of glutaraldehyde (0.025%). Normal and partially hardened RBCs, labeled with 51Cr or 111In, were injected into the femoral vein, while an equal volume of blood was simultaneously withdrawn from the femoral artery. Approximately 70% of the labeled, partially hardened RBCs disappeared from the circulating blood within 25 min after injection, compared with less than 2% of the labeled normal RBCs. The relative distribution of RBCs with reduced deformability to normal RBCs in tissues was determined from radioactivity counting; this ratio (mean +/- SD) was 7.95 +/- 0.85 in the spleen, 7.44 +/- 0.43 in the sternum, 7.10 +/- 1.09 in the lung, 4.54 +/- 0.31 in the liver, and 3.50 +/- 0.61 in the femur bone. The results indicate a significant degree of trapping of RBCs with reduced deformability in these regions. This ratio of relative distribution of RBCs with reduced deformability as compared with normal RBCs was 1.06 +/- 0.13 in the heart, indicating the absence of preferential trapping of RBCs with reduced deformability in this organ. Regional blood flows were determined with 15-microns microspheres in the control period and after infusion of RBCs with reduced deformability (experimental).(ABSTRACT TRUNCATED AT 250 WORDS)

Age-related changes in regional blood flow in the rat

1985 ◽  
Vol 249 (3) ◽  
pp. H485-H491 ◽  
Author(s):  
R. F. Tuma ◽  
G. L. Irion ◽  
U. S. Vasthare ◽  
L. A. Heinel
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Cardiac Index ◽  
Regional Blood Flow ◽  
Adult Rats ◽  
Blood Flows ◽  
Arterial Blood ◽  
Anesthetized Rats ◽  
Regional Blood Flows ◽  
Central Hemodynamic

The purpose of this investigation was to characterize the changes in regional blood flow and central hemodynamic measures that occur in the rat as a result of the aging process. The isotope-labeled microsphere technique was used to measure cardiac output and regional blood flows in conscious and anesthetized adult (12 mo) and senescent (24 mo) Fischer 344 virgin female rats. No significant changes were observed in central hemodynamic measurements or regional blood flows in conscious rats with the exception of a 25% reduction in splenic blood flow. Pentobarbital anesthesia significantly reduced cardiac index and heart rate but elevated total peripheral resistance and mean arterial blood pressure. There was a decrease in blood flow to skeletal muscle, spleen, duodenum, stomach, and brain tissue samples and increased hepatic arterial blood flow in both age groups. The use of anesthesia caused a greater reduction in the cardiac index and brain blood flow in the senescent anesthetized rats than in the adult rats. Heart and kidney blood flows were decreased by anesthesia in the senescent rats but not in the adult rats. Skeletal muscle blood flow, however, was significantly greater in the senescent anesthetized rats than in the younger anesthetized animals. Although body weight and organ weights of the liver, spleen, kidneys, stomach, heart, and brain were significantly greater for the senescent rats, no differences could be demonstrated in tibial length or lean body mass.

A study of the deformability of red blood cells of a teleost fish, the yellowtail (Seriola quinqueradiata), and a comparison with human erythrocytes

1982 ◽  
Vol 96 (1) ◽  
pp. 209-220
Author(s):  
G. M. Hughes ◽  
Y. Kikuchi ◽  
H. Watari
Keyword(s):  
Blood Flow ◽  
Red Blood Cells ◽  
Human Blood ◽  
Blood Cells ◽  
Blood Flow Rate ◽  
Blood Flows ◽  
Human Red Blood Cells ◽  
Seriola Quinqueradiata ◽  
Flow Through ◽  
Environmental Temperatures

The blood of a carangid fish, the yellowtail (Seriola quinqueradiata) has been studied with particular reference to the deformability properties of the red blood cells. The rate at which blood flows through a Nuclepore filter containing 5 micrometers pores has been determined under the same conditions that have been used with human blood. Marked differences were found in the flow of yellowtail blood which depended on the particular way in which the blood had been sampled. Such differences seem to be due to a sensitivity of fish red blood cells to their environmental conditions. Blood flow through filters is temperature-dependent, the rate increasing with a rise in temperature. Measurements made at 37 degrees C gave values which were similar to those normally obtained for human red blood cells, in spite of their greater dimensions (10.4 × 6.8 × 3.4 micrometers), and nucleated nature. It was also found that the blood flow rate of human blood was slower than that of yellowtail blood when measured at the normal environmental temperatures (15 degrees C) for these fish.

High correlation of fractals for regional blood flows among resting and exercising skeletal muscles

1995 ◽  
Vol 269 (1) ◽  
pp. H7-H13 ◽  
Author(s):  
P. O. Iversen ◽  
G. Nicolaysen
Keyword(s):  
Blood Flow ◽  
Skeletal Muscles ◽  
Regional Blood Flow ◽  
Fractal Dimensions ◽  
Strongly Correlated ◽  
Blood Flows ◽  
Exercise Hyperemia ◽  
Regional Blood Flows ◽  
Resting Muscle ◽  
Surprising Finding

The regional blood flow distributions within single skeletal muscles are markedly uneven both at rest and during exercise hyperemia. Fractals adequately describe this perfusion heterogeneity in the resting lateral head of the gastrocnemius muscle as well as in the myocardium. Recently, we provided evidence that the fractal dimension for the blood flow distributions in this resting muscle was strongly correlated with that of the myocardium in the same rabbit. Prompted by this hitherto unknown observation, we have now examined 1) whether fractals also describe perfusion distributions within muscles with a varying metabolic activity, and 2) whether the fractal dimensions for blood flow distributions to these muscles were correlated. We used pentobarbital-anesthetized rabbits and cats. The regional distributions of blood flow within various skeletal muscles were estimated by microsphere trapping. The data unequivocally showed that the perfusion distributions could be described with fractals both in resting and in exercising muscle in both species, the corresponding fractal dimensions ranging from 1.36 to 1.41. The fractal dimensions were markedly correlated (r2 ranged from 0.82 to 0.88) when both various resting and resting plus exercising muscles were compared in the same animal. This surprising finding of high correlations for the fractal dimensions among various muscles within one animal provides a novel characteristic of blood flow heterogeneity.

Fever and regional blood flows in wethers and parturient ewes

1988 ◽  
Vol 65 (1) ◽  
pp. 165-172 ◽  
Author(s):  
C. M. Blatteis ◽  
J. R. Hales ◽  
A. A. Fawcett ◽  
T. A. Mashburn
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Regional Blood Flow ◽  
Flow Distribution ◽  
Full Term ◽  
Blood Flows ◽  
Pregnant Sheep ◽  
Regional Blood Flows ◽  
Placental Blood ◽  
Placental Blood Flow

To determine whether the reported absence of fever in full-term-pregnant ewes might be associated with shifts of regional blood flows from thermogenic tissues to placenta during this critical period, fevers were induced twice by injections of Escherichia coli lipopolysaccharide (LPS, 0.25 microgram/kg iv) into each of six Merino ewes from 8 to 1 days prepartum, and their regional blood flow distribution was measured with radioactive, 15-microns-diam microspheres before and during the rise in fever (when their rectal temperature had risen approximately 0.4 degree C). Unexpectedly, fever always developed, rising to heights not significantly different at any time before parturition [4-8 days prepartum = 0.81 +/- 0.23 degree C (SE); 1-3 days prepartum = 0.75 +/- 0.17 degree C) and similar to those in three wethers treated similarly (0.90 +/- 0.10 degree C). Generally, during rising fever, blood flow in the ewes shifted away from heat loss tissues (e.g., skin, nose) to heat production tissues (e.g., shivering muscle, fat) and cardiac output increased; blood flow through redistribution organs (e.g., splanchnic bed) decreased. The reverse occurred during defervescence. Utero-placental blood flow remained high in the febrile ewes. These regional blood flow distributions during febrigenesis and lysis are essentially the same as those during exposures to ambient cold and heat, respectively. Some differences in the responses of cardiac output and its redistribution, however, were apparent between wethers and pregnant ewes. We conclude that 1) the previously reported "absence of fever in the full-term-pregnant sheep" should not be regarded as a general phenomenon and 2) full-term-pregnant sheep support fever production without sacrificing placental blood flow.

scholarly journals Distribution of maternal and fetal blood flow within cotyledons of the sheep placenta

1981 ◽  
Vol 241 (4) ◽  
pp. H486-H496 ◽  
Author(s):  
G. G. Power ◽  
P. S. Dale ◽  
P. S. Nelson
Keyword(s):  
Blood Flow ◽  
Spatial Organization ◽  
Jugular Vein ◽  
Placental Tissue ◽  
Small Samples ◽  
Flow Ratio ◽  
Fetal Blood ◽  
Blood Flows ◽  
Blood Flow Ratio ◽  
Blood Flow Control

These studies explore the distribution of blood flow among small samples of placental tissue. Labeled microspheres (14 +/- 1 micrometers, SD) were injected into the left ventricle of six unanesthetized ewes and into the jugular vein of the fetuses in utero. A total of 3,576 samples weighing 31 +/- 11 (SD) mg were taken from 17 cotyledons and counted for flow labels. Maternal and fetal blood flow within the cotyledons were both normally distributed with standard deviations of 44%. The maternal-fetal blood flow ratio was less than 0.5 in 9% of the cotyledon, between 0.5 and 1.5 in 70%, and greater than 1.5 in 21%. Errors caused by the method were estimated to contribute less than 10% of the flow variances. Maternal and fetal blood flows were significantly correlated (r = 0.57, P less than 0.001), and both exhibited spatial organization. Calculations based on mathematical models suggested that the observed distribution of the ratio of maternal to fetal blood flow may explain about 50% of the uterine-umbilical venous oxygen tension difference. It was concluded that the samples studied were small in comparison with the dimensions of placental oxygen exchange but may have been similar in size to the dimensions of blood flow control.

Microheterogeneity of myocardial blood flow in rabbit hearts during normoxic and hypoxic states

1996 ◽  
Vol 270 (2) ◽  
pp. H435-H441 ◽  
Author(s):  
T. Matsumoto ◽  
M. Goto ◽  
H. Tachibana ◽  
Y. Ogasawara ◽  
K. Tsujioka ◽  
...  
Keyword(s):  
Blood Flow ◽  
Left Ventricle ◽  
Myocardial Blood Flow ◽  
Regional Blood Flow ◽  
Blood Flows ◽  
Regional Blood Flows ◽  
Novel Method ◽  
Blood Flow Patterns ◽  
Hypoxic State ◽  
Blood Flow Heterogeneity

The goal of this study was to evaluate microheterogeneity of myocardial blood flow and its dependence on arterial O2 tension (PaO2). We measured within-layer distribution of regional blood flows in the left ventricles of anesthetized rabbits in both normoxic and hypoxic states with myocardial region sizes in the range of 0.01-1.0 mm2. A novel method of digital radiography combined with the technique of 3H-labeled desmethylimipramine deposition enabled us to visualize and accurately quantitate regional blood flow at such high levels of resolution. To analyze myocardial blood flow patterns, we computed the coefficient of variation (CV) and the correlation between adjacent regional flows (CA). The CA values were larger in the hypoxic state (PaO2 = 26 +/- 5 mmHg) than in the normoxic state (PaO2 = 97 +/- 20 mmHg) at all levels of resolution (P < 0.001). In the normoxic state, there was a transmural difference in CA (P < 0.001); CA increased with depth of the left ventricle (from subepicardium to subendocardium). However, the relation between CA and the depth of the left ventricle was not statistically significant in the hypoxic state. The CV values were smaller in the hypoxic state than in the normoxic state at all levels of resolution (P < 0.001). When the degree of resolution was reduced from 0.01 to 1.0 mm2, CV decreased by 75% in the normoxic and by 69% in the hypoxic state. Thus we conclude that 1) the decrease in PaO2 increases similarity of blood flows in nearby regions and decreases myocardial blood flow heterogeneity, and 2) similarity of regional blood flows increases with depth of the left ventricle in the normoxic state, but this transmural difference disappears in the hypoxic state.

THE EFFECT OF A CHRONIC CATHETERIZATION PROCEDURE ON REGIONAL BLOOD FLOW AND CARDIO-PULMONARY PARAMETERS IN THE LABORATORY RAT

1986 ◽  
Vol 66 (2) ◽  
pp. 553-557
Author(s):  
D. D. KITTS ◽  
S. J. YEE ◽  
A. L. SCHAEFER
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Key Words ◽  
Regional Blood Flow ◽  
Blood Gases ◽  
Blood Collection ◽  
Blood Flows ◽  
Regional Blood Flows ◽  
Anaesthetized Rat ◽  
Catheterization Procedure

A blood collection technique for conscious, catheterized, unrestrained rats was standardized. Regional blood flows to the heart, brain and viscera were significantly lower in the anaesthetized rat and followed the decline observed in cardiac output. A recovery of all measured physiological parameters to stable levels required approximately 20 min. Key words: Chronically catheterized rats, anaesthesia, blood gases, regional blood flow

Use of microspheres in measurement of regional blood flows during +GZ stress

1979 ◽  
Vol 47 (6) ◽  
pp. 1148-1156 ◽  
Author(s):  
M. H. Laughlin ◽  
J. W. Burns ◽  
F. M. Loxsom
Keyword(s):  
Blood Flow ◽  
Regional Blood Flow ◽  
Aortic Pressure ◽  
Aortic Blood Flow ◽  
Miniature Swine ◽  
Blood Flows ◽  
Aortic Blood ◽  
High Acceleration ◽  
Regional Blood Flows ◽  
Aortic Blood Pressure

The use of the radiolabeled microsphere technique for the study of the effects of +GZ acceleration on regional blood flow is examined. A theoretical analysis of the limits of this technique in a high acceleration environment is presented. Chronically implanted, electromagnetic, aortic flow probes were used to determine the relationship between aortic blood flow velocity and +GZ acceleration in conscious adult miniature swine. It was found that conscious straining adult miniature swine, with the assistance of an inflated anti-G suit, are able to compensate quite well to acceleration levels less than or equal to +7 GZ. Exposure to +9 GZ often resulted in unstable cardiovascular states involving relative bradycardia, often progressing to asystole, declining aortic blood pressure, and markedly diminished cardiac outputs approaching zero. It was found that, if aortic pressure and heart rate attain a relatively steady state during acceleration, and if heart level mean aortic pressure is greater than or equal to 100 Torr, the application of the microsphere technique during +GZ acceleration is theoretically valid. This hypothesis was tested using the microsphere technique (9.0 +/- 0.8 microns diam) in conscious miniature swine during exposure to +GZ acceleration. It is concluded that within the defined limits the radiolabeled microsphere technique is as accurate for use during acceleration studies as it is for use in routine laboratory studies.

scholarly journals Mathematical Models for Some Aspects of Blood Microcirculation

Symmetry ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 1020
Author(s):  
Angiolo Farina ◽  
Antonio Fasano ◽  
Fabio Rosso
Keyword(s):  
Blood Flow ◽  
Mathematical Models ◽  
Red Blood Cells ◽  
Blood Cells ◽  
Blood Rheology ◽  
Small Class ◽  
Small Vessels ◽  
Blood Microcirculation ◽  
Peculiar Behavior

Blood rheology is a challenging subject owing to the fact that blood is a mixture of a fluid (plasma) and of cells, among which red blood cells make about 50% of the total volume. It is precisely this circumstance that originates the peculiar behavior of blood flow in small vessels (i.e., roughly speaking, vessel with a diameter less than half a millimeter). In this class we find arteriolas, venules, and capillaries. The phenomena taking place in microcirculation are very important in supporting life. Everybody knows the importance of blood filtration in kidneys, but other phenomena, of not less importance, are known only to a small class of physicians. Overviewing such subjects reveals the fascinating complexity of microcirculation.

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