Pseudocolor display of regional organ blood flow determined by means of the radioactive microsphere technique

1990 ◽  
Vol 14 (1) ◽  
pp. 1-11 ◽  
Author(s):  
W. Gross ◽  
P. Zeller ◽  
U. Kreimeier ◽  
K. Messmer
Keyword(s):  
Blood Flow ◽  
Organ Blood Flow ◽  
Radioactive Microsphere ◽  
Radioactive Microsphere Technique

Chronic portal hypertension: effects on gastrointestinal blood flow distribution

1986 ◽  
Vol 250 (4) ◽  
pp. G535-G539 ◽  
Author(s):  
J. N. Benoit ◽  
W. A. Womack ◽  
R. J. Korthuis ◽  
W. H. Wilborn ◽  
D. N. Granger
Keyword(s):  
Blood Flow ◽  
Portal Hypertension ◽  
Flow Distribution ◽  
Histological Evaluation ◽  
Organ Blood Flow ◽  
Blood Flow Distribution ◽  
Radioactive Microsphere ◽  
Radioactive Microsphere Technique ◽  
Gastrointestinal Blood Flow ◽  
Muscularis Externa

The intramural distribution of blood flow in the gastrointestinal tract was measured in shamoperated control and portal vein-stenosed rats. Total organ blood flow, measured via the radioactive microsphere technique, was elevated in the esophagus (66%), stomach (102%), duodenum (42%), jejunum (52%), ileum (54%), and colon (79%) of portal-hypertensive rats. Histological evaluation of carbonized nonradioactive 15-microns microspheres allowed for fractionation of blood flow within the wall (mucosa, submucosa, and muscularis externa) of each organ. The microsphere distribution pattern indicates that intramural blood flow distribution in all organs was not dramatically affected by chronic portal hypertension. These findings further define the characteristics of the factors responsible for the gastrointestinal hyperemia produced by chronic portal hypertension.

Hyperdynamic sepsis depresses circulatory compensation to normovolemic anemia in conscious rats

1996 ◽  
Vol 80 (2) ◽  
pp. 656-664 ◽  
Author(s):  
H. Morisaki ◽  
W. Sibbald ◽  
C. Martin ◽  
G. Doig ◽  
K. Inman
Keyword(s):  
Blood Cells ◽  
Cecal Ligation ◽  
Rat Plasma ◽  
Organ Blood Flow ◽  
Radioactive Microsphere ◽  
Radioactive Microsphere Technique ◽  
Normovolemic Anemia ◽  
O2 Delivery ◽  
Relevant Range ◽  
Hyperdynamic Sepsis

This study was designed to determine whether sepsis modifies the ability to preserve vital organ O2 delivery (QO2) across a clinically relevant range of hematocrits. Ninety rats were randomly allocated to cecal ligation and perforation (CLP) or a sham (Sham) procedure. With the use of rat plasma, rat whole blood, or packed rat red blood cells, respectively, randomization into three different hematocrit subgroups followed: low (21-28%), middle (33-40%), and high (45-52%). Organ blood flow values (Q) were measured by the radioactive microsphere technique, and organ QO2 values were calculated. Twenty-four hours after laparotomy, the hematocrit grouping had not modified the interorgan distribution of Q or QO2 in either the CLP or Sham rats. To characterize overall metabolic O2 reserve, rats were then exposed to hypoxia (inspired O2 fraction, 0.08) for 20 min. Whereas cardiac output increased significantly during hypoxia in all experimental groups, myocardial QO2 failed to increase in the low hematocrit Sham subgroup and fell significantly in both the middle- and low-hematocrit CLP subgroups. There was also a lesser redistribution of QO2 away from the small intestine in the low-hematocrit compared with the high-hematocrit CLP subgroup. We conclude that myocardial QO2 is more effectively maintained in septic hypoxic rats if the hematocrit is maintained at levels =45%.

Effect of exercise on uterine blood flow in the pregnant Pygmy goat

1984 ◽  
Vol 246 (2) ◽  
pp. H207-H212 ◽  
Author(s):  
A. R. Hohimer ◽  
J. M. Bissonnette ◽  
J. Metcalfe ◽  
T. A. McKean
Keyword(s):  
Blood Flow ◽  
Uterine Artery ◽  
Artery Blood Flow ◽  
Normal Birth Weight ◽  
Uterine Blood Flow ◽  
Normal Birth ◽  
Radioactive Microsphere ◽  
Radioactive Microsphere Technique ◽  
Placental Blood ◽  
Placental Blood Flow

Pygmy goats in the last third of pregnancy were trained to walk on a treadmill at rates up to 2.0 mph and up an inclination of 0-15 degrees. Electromagnetic flowmeters were placed unilaterally on a uterine artery, and measurements were made while the goats were standing quietly on the treadmill and during 5 min of exercise. Blood flow fell during exercise in all five animals studied, and this reduction was proportional to the level of exertion. At the highest level of exercise that these animals would voluntarily perform, uterine artery blood flow fell by 32 +/- 3 (SE) % (P less than 0.001) from control. In four additional animals the radioactive microsphere technique was used to measure uterine blood flow at rest and after 5-7 min of exercise. In these animals, exercise caused total uterine blood flow to fall by 18 +/- 10%; cotyledonary (placental) blood flow fell by 8 +/- 13%, while myoendometrial blood flow decreased by 52 +/- 12% (P less than 0.05). Thus nonplacental portions of the pregnant Pygmy goat uterus suffer major reductions in blood flow during exercise. This vasoconstriction may be due to exercise per se or to concomitant hypocapnia or hyperthermia. Singleton and twin kids born to animals that exercised were of normal birth weight.

Role of ethanol metabolism in the ethanol-induced increase in splanchnic circulation

1986 ◽  
Vol 250 (4) ◽  
pp. G518-G523 ◽  
Author(s):  
J. P. McKaigney ◽  
F. J. Carmichael ◽  
V. Saldivia ◽  
Y. Israel ◽  
H. Orrego
Keyword(s):  
Blood Flow ◽  
Liver Blood Flow ◽  
Portal Blood Flow ◽  
Splanchnic Blood Flow ◽  
Ethanol Metabolism ◽  
Radioactive Microsphere ◽  
Splanchnic Hemodynamics ◽  
Radioactive Microsphere Technique ◽  
Blood Flow Increase

In this study we report the effect on splanchnic hemodynamics of acute oral ethanol at doses ranging from 0.25 to 4.0 g/kg body wt. Flows were determined by use of a radioactive microsphere technique. Ethanol was found to increase portal blood flow by 23-57%. In awake rats this increase reached a plateau at the 0.5 g/kg dose. In ketamine-anesthetized rats, the increase was observed only at doses of 3.0 g/kg or more, with the response at doses of 0.5, 1.0, and 2.0 g/kg being suppressed by ketamine. Inhibition of alcohol dehydrogenase by intra-arterial administration of 4-methylpyrazole resulted in suppression of the liver blood flow increase after ethanol was administered to awake animals. Ethanol in the range of doses studied did not result in changes in blood glucagon levels. Rats fed ethanol-containing diets for 4 wk and withdrawn for 18 h had the same response to acute oral ethanol as did naive rats. It is suggested that ethanol metabolism mediates the effects of ethanol on splanchnic blood flow. An increase in splanchnic blood flow when concurrent with an increase in liver O2 consumption induced by ethanol might protect the liver from hypoxic damage.

Hemodynamic disturbances in the rat as a function of the number of microspheres injected

1983 ◽  
Vol 245 (6) ◽  
pp. H920-H923 ◽  
Author(s):  
K. A. Stanek ◽  
T. L. Smith ◽  
W. R. Murphy ◽  
T. G. Coleman
Keyword(s):  
Heart Rate ◽  
Blood Flow ◽  
Reference Sample ◽  
Flow Distribution ◽  
Fluid Replacement ◽  
Blood Flow Distribution ◽  
Radioactive Microsphere ◽  
Electromagnetic Flowmetry ◽  
Radioactive Microsphere Technique ◽  
Hemodynamic Disturbance

The purpose of this study was to reevaluate the radioactive microsphere technique used to measure blood flow distribution. The rats were conscious when studied. A dextrose solution with specific gravity of 1.3 was used as the suspension media instead of 10% dextran, which has previously been shown to cause hypotension. The microspheres were injected into the left atrium, which provided for maximal mixing with the blood before being ejected into the aortic arch. Ficoll-70 was given after each reference sample as a fluid replacement. With these modifications an injection of 360,000 microspheres or less caused no hemodynamic disturbances, as judged by electromagnetic flowmetry. After 1.4 X 10(6) microspheres had accumulated in the rat (several injections) the only significant hemodynamic disturbance was a decreased heart rate. This study establishes the limits in the rat regarding the number of microspheres that can be injected before hemodynamic disturbances result.

Postprandial hemodynamics in the conscious rat

1986 ◽  
Vol 251 (1) ◽  
pp. G117-G123 ◽  
Author(s):  
L. Anzueto Hernandez ◽  
P. R. Kvietys ◽  
D. N. Granger
Keyword(s):  
Blood Flow ◽  
Mixed Meal ◽  
Conscious Rat ◽  
Conscious Rats ◽  
Blood Flows ◽  
Radioactive Microsphere ◽  
Radioactive Microsphere Technique ◽  
Bowel Segments ◽  
Conscious Animals ◽  
Hyperemic Response

The postprandial intestinal hyperemia was studied in conscious and anesthetized rats using the radioactive microsphere technique. Carbohydrate, protein, lipid, and mixed meals, and the vehicle (Tyrode's solution), were placed in the stomach via a gastrostomy tube. In conscious rats, blood flow increased by 40-80% in the duodenum and jejunum 1 h after either a carbohydrate, lipid, protein, or mixed meal. Tyrode's solution produced a comparable hyperemia. Blood flow in the distal bowel segments (ileum, cecum, and colon) was significantly increased only by Tyrode'ds solution and the carbohydrate meal. The proximal intestinal hyperemia produced by the mixed meal in conscious animals was significantly attenuated by vagotomy yet unaltered by atropine pretreatment. In contrast to the results obtained from conscious rats, the mixed meal did not significantly alter intestinal blood flow in anesthetized animals. The results of this study indicate that the postprandial intestinal hyperemia is much greater in conscious than anesthetized animals. This difference may result from the higher resting blood flows in the latter group. The hyperemic response in conscious animals may be mediated by the vagus nerve.

Splanchnic and systemic hemodynamics in mice using a radioactive microsphere technique

1990 ◽  
Vol 258 (3) ◽  
pp. G365-G369 ◽  
Author(s):  
S. K. Sarin ◽  
C. Sabba ◽  
R. J. Groszmann
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Carotid Artery ◽  
Conventional Technique ◽  
Whole Body ◽  
Unit Weight ◽  
Radioactive Microsphere ◽  
Cardiac Output Determination ◽  
Radioactive Microsphere Technique ◽  
Regional Hemodynamics

Mice are commonly used for the study of human disease processes. However, techniques for measuring systemic and hepatic blood flow in mice have not been developed. We attempted the conventional technique of radiolabeled microsphere injection into the left ventricle, but difficulties were encountered, including unsuspected ventricular perforation and outflow obstruction in 68% of the animals. We therefore evaluated whether an injection into the carotid artery close to the aortic arch can fulfill the criteria (approximately or greater than 300 microspheres in femoral blood or tissues, adequate mixing of microspheres with blood, and no significant alteration of blood pressure during microsphere injection) required for accurate measurement of systemic and regional hemodynamics. Carotid artery injection resulted in adequate mixing and number of microspheres in tissues in 78 and 91% of the animals, respectively. Portal venous inflow was 1.8 +/- 0.3 ml.min-1.g liver tissue-1 and renal blood flow was 5.1 +/- 0.75 ml.min-1.g tissue-1. Compared per unit weight, these values are quite similar to those reported in rats. Cardiac output was 12.1 +/- 1.2 ml/min and cardiac index was 462 +/- 47 ml.min-1.kg body wt-1. The reliability of cardiac output determination is improved if whole body radioactivity is taken into account. Five of 22 animals had to be excluded because of either a low number of microspheres in tissues or inadequate mixing of microspheres with blood (shown by asymmetrical distribution of microspheres between left and right kidney). With modifications, the radioactive microsphere technique can be adapted to the hemodynamic study of mice.

scholarly journals Spinal Cord Blood Flow Measured with Microspheres Following Spinal Cord Injury in the Rat

1986 ◽  
Vol 13 (2) ◽  
pp. 91-96 ◽  
Author(s):  
M. Christopher Wallace ◽  
Charles H. Tator
Keyword(s):  
Spinal Cord ◽  
Spinal Cord Injury ◽  
Blood Flow ◽  
Cord Blood ◽  
Systemic Arterial Pressure ◽  
Compression Injury ◽  
Spinal Cord Blood Flow ◽  
Radioactive Microsphere ◽  
Cord Injury ◽  
Radioactive Microsphere Technique

ABSTRACT:A decrease in spinal cord blood flow (SCBF) is a known sequela of spinal cord injury. The radioactive microsphere technique permits repeated measurement of spinal cord blood flow (SCBF) and cardiac output (CO) in the same experimental animal. The purpose of this study was to adapt the radioactive microsphere technique for use in the rat extradural clip compression injury model used in our laboratory.Thirteen adult Wistar rats were anaesthetized and ventilated. Mean systemic arterial pressure (MSAP) was recorded continuously. Control animals (n = 8) did not have a surgical procedure whereas the injured animals (n = 5) underwent a C7-T1 laminectomy followed by a one minute, 50 gram extradural clip compression injury at Tl. Radioactive microspheres were used for two blood flow and CO determinations in both groups.MSAPfell 59% in the injured animals (p<0.01), but this was not accompanied by significant changes in heart rate or CO. There was a 50% reduction in SCBF in the injured cord (p<0.02), and there were significant reductions in cerebral blood flow (p<0.05) and cerebellar blood flow (p<0.02) following spinal cord injury.

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