Bone blood flow measured by 85 Sr microspheres and bone seeker clearances in the rat

1979 ◽  
Vol 236 (1) ◽  
pp. H1-H6 ◽  
Author(s):  
A. Schoutens ◽  
P. Bergmann ◽  
M. Verhas
Keyword(s):  
Blood Flow ◽  
Left Ventricle ◽  
Intravenous Injection ◽  
Plasma Flow ◽  
Extraction Ratio ◽  
Bone Blood Flow ◽  
Blood Flows ◽  
Heating And Cooling ◽  
Physiological Values ◽  
The Relationship

This paper investigates further the relationship between the initial bone clearance of a bone-seeking radioisotope or labeled substance and the bone blood flow. The bone blood flow of rats was modified over the widest possible range of physiological values by heating and cooling their hindlimbs. Osseous blood flow was measured by the arteriolar trapping of labeled microspheres of 15 micrometer diameter injected into the left ventricle. The plasma clearances of 45Ca and 99 m Tc by bone were measured 10 min after the intravenous injection of radiocalcium and of 99 m technetium pyrophosphate. The extraction ratio for 45Ca over the 10-min interval (45Ca clearance/bone plasma flow) was 0.60 for low blood flows, 0.40 for blood flows at rest, and 0.25 for high values of flow. The data for 99 m Tc were, respectively, 0.68, 0.34, and 0.22. Initial bone clearances of either substance should not be used to measure the increases in bone blood flow over the values at rest.

Relationship between portal venous and hepatic arterial blood flows: spectrum of response

1990 ◽  
Vol 259 (6) ◽  
pp. G1010-G1018 ◽  
Author(s):  
T. Kawasaki ◽  
F. J. Carmichael ◽  
V. Saldivia ◽  
L. Roldan ◽  
H. Orrego
Keyword(s):  
Blood Flow ◽  
Arterial Blood Flow ◽  
Portal Vein Ligation ◽  
Artery Ligation ◽  
Blood Flows ◽  
Arterial Blood ◽  
Group A ◽  
Group B ◽  
The Relationship ◽  
Group D

The relationship between portal tributary blood flow (PBF) and hepatic arterial blood flow (HAF) was studied in awake, unrestrained rats with the radiolabeled microsphere technique. Six distinct patterns of response emerged. In group A (PBF+, HAF 0), ethanol, acetate, glucagon, prostacyclin, and a mixed diet increased PBF without a change in HAF; in group B (PBF+, HAF+), adenosine and histamine increased both PBF and HAF; in group C (PBF 0, HAF+), isoflurane and triiodothyronine did not change PBF but increased HAF; and in group D (PBF-, HAF+), halothane and vasopressin decreased PBF and increased HAF. Acute partial portal vein ligation decreased PBF (56%) and increased HAF (436%). Hypoxia (7.5% O2) decreased PBF (28%) and increased HAF (110%). In group E (PBF+, HAF-), acute hepatic artery ligation increased PBF (35%) and reduced HAF (74%), while in group F (PBF-, HAF-), thyroidectomy reduced PBF and HAF (36 and 47%, respectively). All blood flow responses were accompanied by the expected changes in both portal tributary and hepatic arterial vascular resistances. The data suggest that the portal and hepatic arterial vascular territories have regulatory mechanisms that allow for independent changes.

Influence of sodium pentobarbital on splanchnic blood flow and related functions

1959 ◽  
Vol 197 (3) ◽  
pp. 624-626 ◽  
Author(s):  
Ann Evringham ◽  
Edith M. Brenneman ◽  
Steven M. Horvath
Keyword(s):  
Blood Flow ◽  
Oxygen Consumption ◽  
Intravenous Injection ◽  
Anesthetic Agent ◽  
Splanchnic Blood Flow ◽  
Sodium Pentobarbital ◽  
Hepatic Circulation ◽  
Blood Flows

Eleven mongrel dogs were trained to lie quietly while splanchnic blood flows and splanchnic metabolisms were determined. They were then anesthetized by means of intravenous injection of 28.4 mg/kg of sodium pentobarbital and studies of the hepatic circulation continued for an additional 70 minutes. Only minor, transitory alterations were observed in the parameters being measured. It was concluded that with this particular anesthetic agent splanchnic blood flows and oxygen consumption were essentially at control unanesthetized levels within 30–45 minutes postanesthesia.

Measurements of Hemodialysis Catheter Blood Flow in Vivo

2002 ◽  
Vol 25 (4) ◽  
pp. 276-280 ◽  
Author(s):  
Z. J. Twardowski ◽  
J. D. Haynie
Keyword(s):  
Blood Flow ◽  
Average Length ◽  
Internal Diameter ◽  
Hemodialysis Catheter ◽  
Blood Flows ◽  
Catheter Design ◽  
Poiseuille’S Equation ◽  
Different Diameters ◽  
The Relationship

The relationship between the blood flow and inflow and outflow pressures was determined in PermCath, dual lumen catheters during regular hemodialyses in vivo in eight patients with average hematocrit of 38%. From the luer lock connector the catheters had an average length of 32 cm to the outflow tip and 30 cm to the inflow tip. The catheters had an internal diameter of 0.2 cm and were straight before implantation. Dialyses were performed on Fresenius 2008 D or E machines with ReadySet™ blood lines with an 8 mm ID pump segment and a noncollapsible arterial chamber. Pressures and blood flows were measured at pump speeds from 50 to 500 ml/min in increments of 50 ml/min with lines in normal configuration. Blood flow was measured continuously using ultrasound. The correlations between pressures and flows are not linear. The best correlations are according to the Stirling model of exponential growth category equation. Inflow pressure = -9.07–0.4865*(exp(0.0020*blood flow)-1)/0.0020 Outflow pressure = -28.14+0.5002*(exp(0.0015*blood flow)-1/0.0015 Based on these results and Poiseuille's equation a table was developed for the optimal relationship between catheter length and diameter to achieve standardized (average, low and high) blood flows regardless of the lengths of the catheters. The diameter/length relationships are based on theoretical considerations. Because resistances depend on the material and shape of the tubing, the actual measurements of flow/pressure relationships should be done once tubings of different diameters are manufactured, and final catheter design has to be based on these measurements.

Effects of intra-arterial arginine-vasopressin infusions on peripheral blood flows in conscious dogs

1986 ◽  
Vol 71 (6) ◽  
pp. 713-721 ◽  
Author(s):  
Jean-Francois Liard
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Small Intestine ◽  
Arginine Vasopressin ◽  
Muscle Blood Flow ◽  
Plasma Concentrations ◽  
Abdominal Fat ◽  
Conscious Dogs ◽  
Bone Blood Flow ◽  
Blood Flows

1. We reported in an earlier study that intravenous infusions of arginine-vasopressin (AVP), 220 pg min−1 kg−1 for 1 h, substantially reduced blood flow to the skin, skeletal muscle, pancreas, colon, small intestine, abdominal fat and myocardium [1] in conscious dogs. In the present study, we infused AVP directly into the artery supplying these organs and tissues in order to determine the relative contribution of local versus systemic mechanisms in the vascular resistance changes previously observed. 2. Regional blood flows were measured with radioactive microspheres in conscious, chronically instrumented dogs before and during intra-arterial infusions of AVP administered into the left axillary artery (n = 6), the left coronary artery (n = 6), and the cranial mesenteric artery (n = 6). The infusion rates were calculated to increase local, target organ plasma concentrations of AVP to the levels reached in our previous study while minimizing systemic changes. 3. Left axillary AVP artery infusion significantly reduced skin and compact bone blood flow, but had no effect on skeletal muscle blood flow. Intra-coronary AVP infusion had no effect on myocardial blood flow nor on cardiac output. Intramesenteric AVP infusion had no effect on blood flow to the colon, small intestine and abdominal fat, but significantly reduced blood flow to those areas of the pancreas which received blood from the cannulated artery. 4. Measurements in a limited number of dogs indicated that the local axillary and mesenteric venous levels of AVP were similar when the hormone was infused systemically at a rate of 220 pg min−1 kg−1 or intra-arterially at a lower rate. 5. These findings suggest that the increase in resistance measured in the skeletal muscle, small intestine, colon and abdominal fat after systemic administration of small amounts of AVP results in large part from indirect mechanisms. Direct vasoconstrictor effects of AVP at these plasma concentrations appear limited to the skin, the pancreas and the compact bones.

Cerebral Blood Flow in the Rat

1958 ◽  
Vol 193 (2) ◽  
pp. 272-274 ◽  
Author(s):  
Leo A. Sapirstein ◽  
Gordon E. Hanusek
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Cerebral Blood Flow ◽  
Intravenous Injection ◽  
Extraction Ratio ◽  
Female Rats ◽  
Perfusion Rate ◽  
Single Intravenous Injection ◽  
The Brain ◽  
Fractional Uptake

The cerebral uptake of iodoantipyrine (I131) was measured in anesthetized rats as a function of time after a single intravenous injection. The cerebral content stabilized in 7–9 seconds and remained constant for 64 seconds indicating that the brain and body had the same extraction ratio for the label. The cerebral blood flow fraction therefore corresponded to the fractional uptake of iodoantipyrine by the brain. The cerebral blood flow was calculated as the product of the cardiac output and the cerebral flow fraction. The perfusion rate of the brain was found to be 0.51 ml/gm/min. in female rats.

scholarly journals Extraction Ratio and Bone Clearance of Sr85as a Measure of Effective Bone Blood Flow

1965 ◽  
Vol 16 (5) ◽  
pp. 461-467 ◽  
Author(s):  
DOUGLAS HAROLD COPP ◽  
SUN SHIK SHIM
Keyword(s):  
Blood Flow ◽  
Extraction Ratio ◽  
Bone Blood Flow

Coronary flow by left atrial and left ventricular microsphere injection in the rat

1990 ◽  
Vol 259 (2) ◽  
pp. H635-H638
Author(s):  
G. D. Schrock ◽  
R. L. Krahmer ◽  
J. L. Ferguson
Keyword(s):  
Blood Flow ◽  
Left Ventricle ◽  
Left Atrium ◽  
Coronary Blood Flow ◽  
Left Atrial ◽  
Blood Gases ◽  
Left Ventricular ◽  
Systemic Blood ◽  
Systemic Blood Flow ◽  
Blood Flows

Previous studies have reported significantly higher variability in coronary blood flow (CBF) measurements obtained by microsphere injection into the left ventricle (LV) as compared with microsphere injection into the left atrium (LA) of the rat. Questions have arisen concerning whether or not some of the variability may have been due to successive rather than simultaneous injections at the two sites, thereby giving measurements at different cardiovascular states. To address this question, we measured cardiac output (CO) and CBF as well as other systemic organ blood flows by employing simultaneous injection of two different sets of radiolabeled microspheres into the left atrium and left ventricle of semiconscious rats. Using this technique, CBF values (ml.min-1.g-1) of 5.45 +/- 0.43 and 5.24 +/- 0.46 for LA and LV injection sites, respectively, were measured (all values reported as means +/- SE). CO values (ml/min) of 67.5 +/- 3.5 for LA and 67.6 +/- 3.4 for LV were obtained. Paired left atrial and left ventricular measurements of CBF, CO, and other systemic organ blood flows using tracer microsphere methodology were not significantly different. All variabilities in these measurements by LA and LV injection were not significantly different. Our procedure did not significantly alter physiological parameters such as heart rate, mean arterial pressure, hematocrit, or blood gases. These findings indicate that, in our rat model, measurements made by LV microsphere injection are not only adequate for determining systemic blood flow at distal beds but provide coronary blood flow data with variability not significantly different from that of left atrial injection.

Post-Mortem Migration of Bone-Seeking Radionuclides in the Rat and Rabbit and its Effect on Estimates of Bone Uptake

1978 ◽  
Vol 55 (2) ◽  
pp. 221-223
Author(s):  
P. Tothill ◽  
J. N. MaCpherson
Keyword(s):  
Blood Flow ◽  
Migration Rate ◽  
Linear Increase ◽  
Extraction Ratio ◽  
Bone Blood Flow ◽  
Post Mortem ◽  
Initial Concentration ◽  
Bone Uptake ◽  
High Bone

1. The continued uptake of 18F, 85Sr and 47Ca by bone after death has been studied in rats and rabbits after aortic injection followed by quick killing, a period of recirculation of tracer before death, and perfusion of the carcase. In each case an approximately linear increase of bone radioactivity was observed during a period of 1 h at about the same rate. The proportionate increase depended on the initial concentration of bone-seeking nuclide, ranging from a factor of 1.5 to 4.5. Boiling the carcase did not increase the migration rate. 2. Delay between death and dissection may therefore lead to spuriously high bone concentrations of these radionuclides, leading to overestimates of bone uptake, extraction ratio or bone blood flow.

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