Regional blood flow in the brain and spinal cord of hypothermic rats

1989 ◽  
Vol 257 (3) ◽  
pp. H785-H790
Author(s):  
T. Sakamoto ◽  
W. W. Monafo
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Brain Stem ◽  
Regional Blood Flow ◽  
Experimental Conditions ◽  
Pentobarbital Sodium ◽  
Arterial Blood ◽  
Group A ◽  
Group B ◽  
The Brain

[14C]butanol tissue uptake was used to measure simultaneously regional blood flow in three regions of the brain (cerebral and cerebellar hemispheres and brain stem) and in five levels of the spinal cord in 10 normothermic rats (group A) and in 10 rats in which rectal temperature had been lowered to 27.7 +/- 0.3 degrees C by applying ice to the torso (group B). Pentobarbital sodium anesthesia was used. Mean arterial blood pressure varied minimally between groups as did arterial pH, PO2, and PCO2. In group A, regional spinal cord blood flow (rSCBF) varied from 49.7 +/- 1.6 to 62.6 +/- 2.1 ml.min-1.100 g-1; in brain, regional blood flow (rBBF) averaged 74.4 +/- 2.3 ml.min-1.100 g-1 in the whole brain and was highest in the brain stem. rSCBF in group B was elevated in all levels of the cord by 21-34% (P less than 0.05). rBBF, however, was lowered by 21% in the cerebral hemispheres (P less than 0.001) and by 14% in the brain as a whole (P less than 0.05). The changes in calculated vascular resistance tended to be inversely related to blood flow in all tissues. We conclude that rBBF is depressed in acutely hypothermic pentobarbital sodium-anesthetized rats, as has been noted before, but that rSCBF rises under these experimental conditions. The elevation of rSCBF in hypothermic rats confirms our previous observations.

[14C]butanol distribution: a new method for measurement of spinal cord blood flow

1988 ◽  
Vol 255 (4) ◽  
pp. H953-H959
Author(s):  
T. Sakamoto ◽  
S. Shimazaki ◽  
W. W. Monafo
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Sciatic Nerve ◽  
Regional Blood Flow ◽  
Spinal Cord Blood Flow ◽  
Pentobarbital Sodium ◽  
Group A ◽  
Sciatic Nerves ◽  
Group B ◽  
Stimulation Of

[14C]butanol distribution was used to quantitate regional blood flow (SCBF) in the spinal cord (levels T3-5, T7-9, L1-2, L3-S) and in the sciatic nerves (NBF) of control pentobarbital sodium-anesthetized rats (group A), after 1 h of hemorrhagic hypotension (group B), after 15 min of stimulation of one sciatic nerve (group C-1), and after stimulation of one sciatic nerve plus hemorrhage, which maintained mean arterial pressure (MAP) at control (130 mmHg). Group A SCBF ranged from 52.3 +/- 3.5 (L3-S) to 67.4 +/- 2.7 (L1-2) ml.min-1.100 g-1. NBF was 8.0 +/- 0.9 ml.min-1.100 g-1. Group B SCBF was unchanged. NBF fell to 4.0 +/- 0.4 ml.min-1.100 g-1. Group C-1 SCBF was markedly elevated (range 122 +/- 23.1 to 150.1 +/- 18.7 ml.min-1.100 g-1). NBF was 33.5 +/- 4.1 ml.min-1.100 g-1 (stimulated side) and 14.7 +/- 1.4 ml.min-1.100 g-1 (nonstimulated). MAP was elevated (163 +/- 6 mmHg). In group C-2 (MAP was 130 +/- 4 mmHg), SCBF was still elevated at T3-5, L3-S, and marginally elevated at L1-2. NBF was 22.6 +/- 4.7 ml.min-1.100 g-1 (stimulated) but unchanged contralaterally. [14C]butanol distribution provides a sensitive reproducible measure of SCBF and NBF. Autoregulation of SCBF (but not of NBF) occurred in the range 60-160 mmHg MAP. Spinal cord stimulation via the sciatic nerve increased SCBF two- to threefold, but when hypertension was avoided by blood withdrawal, a modest (38%) increase in SCBF still occurred.

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.

Effects of insulin-like growth factor-I and LR3IGF-I on regional blood flow in normal rats

1997 ◽  
Vol 155 (2) ◽  
pp. 351-358 ◽  
Author(s):  
CM Gillespie ◽  
AL Merkel ◽  
AA Martin
Keyword(s):  
Skeletal Muscle ◽  
Blood Flow ◽  
Vascular Resistance ◽  
Regional Blood Flow ◽  
Arterial Blood ◽  
Cardiovascular Side Effects ◽  
Igf I ◽  
The Central Nervous System ◽  
The Brain ◽  
Infusion Period

Two studies were conducted to investigate the haemodynamic effects of IGF-I and its analogue LR3IGF-I in normal anaesthetised rats. Infusion of IGF-I intravenously, at a dose of 125 micrograms/kg/h, for 20 min in the first study resulted in renal blood flow being significantly elevated by 35% above baseline. Mean arterial blood pressure (MABP) at this IGF-I dose fell by 18% of baseline, with LR3IGF-I also causing a significant decline in MABP (by 15%) at the dose of 125 micrograms/kg/h. In the second study the intravenous administration of IGF-I or LR3IGF-I, at a dose of 125 micrograms/kg/h, over a period of 60 min, resulted in MABP being significantly lowered by 25% of baseline values. Regional blood flow rates were determined using radioactive microspheres, 15 microns in diameter, injected systemically at the end of the peptide infusion period. The gastrocnemius, a representative skeletal muscle, was the only vascular region to show a significant increase in blood flow after IGF-I (by 58%) or LR3IGF-1 (by 308%) infusion. Vascular resistance in the brain was significantly reduced after infusion of IGF-I (by 60%) or LR3IGF-I (by 48%) as compared with vehicle. Skeletal muscle vascular resistance was also reduced by IGF-I (by 41%) and more particularly by LR3IGF-I (by 77%) in comparison to vehicle. These alterations to vascular tone produced by IGF infusion may be related to the central nervous system and systemic cardiovascular side-effects that have been reported during IGF-I administration in humans.

Cardiac output distribution and regional blood flow during hypocarbia in monkeys

1985 ◽  
Vol 58 (4) ◽  
pp. 1225-1230 ◽  
Author(s):  
S. Gelman ◽  
K. C. Fowler ◽  
S. P. Bishop ◽  
L. R. Smith
Keyword(s):  
Blood Flow ◽  
Cardiac Output ◽  
Regional Blood Flow ◽  
Arterial Blood Flow ◽  
Tissue Blood Flow ◽  
Base Line ◽  
Output Distribution ◽  
Arterial Blood ◽  
Cardiac Output Distribution ◽  
The Brain

Cardiac output distribution and regional blood flow were studied during hypocarbia independent of changes in ventilatory parameters. Fifteen cynomolgus monkeys were anesthetized with methohexital sodium (8 mg/kg im) and hyperventilated through an endotracheal tube. Hypocarbia at two levels, 28 +/- 1.8 and 17 +/- 0.6 Torr, was achieved by a stepwise decreasing CO2 flow into the semiclosed system. Regional blood flow was determined with labeled microspheres. At each stage of experiments two sets of microspheres (9 and 15 microns diam) were used simultaneously. The use of two microsphere sizes allowed evaluation of the relationship between total (nutritive and nonnutritive) tissue blood flow, determined with 15-microns spheres, and nutritive blood flow, determined with 9-microns spheres. There was no change in cardiac output or arterial pressure during both degrees of studied hypocarbia. Hypocarbia was accompanied by a decrease in myocardial blood flow determined with 15-microns spheres and preservation of the flow determined with 9-microns spheres. Splenic blood flow was decreased, whereas hepatic arterial blood flow was increased during both levels of hypocarbia. Blood flow through the brain, renal cortex, and gut showed a biphasic response to hypocarbia: during hypocarbia at 28 +/- 1.8 Torr, blood flow determined with 15-microns spheres was unchanged (in the gut) or decreased (in the brain and kidneys), whereas blood flow determined with 9-microns spheres was decreased. During hypocarbia at 17 +/- 0.6 Torr, blood flow determined with 9-microns spheres had a tendency to restore to base-line values.

scholarly journals Perfusion Index Analysis in Patients Presenting to the Emergency Department Due to Synthetic Cannabinoid Use

Medicina ◽  
2019 ◽  
Vol 55 (12) ◽  
pp. 752
Author(s):  
Selman Yeniocak
Keyword(s):  
Emergency Department ◽  
Blood Flow ◽  
Blood Perfusion ◽  
Perfusion Index ◽  
Peripheral Tissue ◽  
Pulsatile Blood Flow ◽  
Cross Sectional ◽  
Arterial Blood ◽  
Group A ◽  
Group B

Background and Objectives: The perfusion index (PI) indicates the ratio of pulsatile blood flow in peripheral tissue to non-pulsatile blood flow. This study was performed to examine the blood perfusion status of tissues and organs of patients using synthetic cannabinoids (SCs). Materials and Methods: The records of patients aged 17 or over presenting to the adult emergency department due to SC use between 1 January 2016 and 31 December 2017 were examined in this single-center, retrospective, cross-sectional study. Examined factors included time from consumption of SC to presentation to the emergency department, as well as simultaneously determined systolic and diastolic blood pressures, heart rate (beats per min), Glasgow Coma Score (GCS), and PI values. Patients were divided into two groups, A and B, depending on the amount of time that had elapsed between SC consumption and presentation to the emergency department, and statistical data were compared. Results: The mean PI value in Group A was lower than that in Group B. Therefore, we concluded that peripheral tissue and organ blood perfusion is lower in the first 2 h following SC consumption than after 2 h. Systolic, diastolic, and mean arterial blood pressure and mean GCS values were also statistically significantly lower in Group A than in Group B. Conclusions: A decreased PI value may be an early sign of reduced-perfusion organ damage. PI is a practical and useful parameter in the early diagnosis of impaired organ perfusion and in monitoring tissue hypoxia leading to organ failure.

The effects of lumbar sympathectomy on regional spinal cord blood flow in rats during acute hemorrhagic hypotension

1992 ◽  
Vol 76 (4) ◽  
pp. 687-691 ◽  
Author(s):  
Atsushi Iwai ◽  
William W. Monafo
Keyword(s):  
Spinal Cord ◽  
Blood Flow ◽  
Cord Blood ◽  
Regional Blood Flow ◽  
Cauda Equina ◽  
Spinal Cord Blood Flow ◽  
Peripheral Tissues ◽  
Biceps Femoris Muscle ◽  
Arterial Blood ◽  
Severe Hypotension

✓ It has not previously been determined whether the sympathetic nervous system has a role in the regulation of regional blood flow in the spinal cord. The authors used 14C-butanol distribution to measure regional spinal cord blood flow at seven cord levels, in the sciatic nerve, and in the biceps femoris muscle in 36 rats, 18 of which had undergone excision of both lumbar sympathetic chains at least 6 days previously. Blood flows were measured during pentobarbital anesthesia. Mean arterial blood pressure (MABP) was monitored and arterial pO2, pCO2, and pH were determined prior to flow measurement. Anesthetic dose and duration were controlled. Measurements were made in normotensive rats and in rats with MABP maintained at either 69 ± 3 mm Hg or 48 ± 3 mm Hg for 1 hour by the withdrawal of arterial blood. One-half of the rats in each group had undergone sympathectomy. The resting cord blood flow was lower than control values following sympathectomy only at the S1–4 cord level (p < 0.01) and cauda equina (p < 0.01), and was marginally lower at the L1-2 and L3–6 levels (p < 0.1). Cord blood flow was unaffected by sympathectomy during moderate hypotension. During severe hypotension, cord blood flow was less than control at the C3–5 level (p < 0.05), but did not differ from control at the other six levels. Flows in nerve and muscle were consistent with known effects of sympathectomy on peripheral tissues. It is concluded that, at most, sympathectomy may moderately decrease resting blood flow in the cord levels caudal to L-1. Sympathectomy has no major effect on regional spinal cord blood flow in rats stressed by either moderate or severe arterial hemorrhage.

Changes in arterioles, arteries, and local perfusion of the brain stem during hemorrhagic hypertension

1996 ◽  
Vol 270 (4) ◽  
pp. H1350-H1354 ◽  
Author(s):  
K. Toyoda ◽  
K. Fujii ◽  
S. Ibayashi ◽  
S. Sadoshima ◽  
M. Fujishima
Keyword(s):  
Blood Flow ◽  
Brain Stem ◽  
Basilar Artery ◽  
Doppler Flowmetry ◽  
Large Arteries ◽  
Cerebrovascular Resistance ◽  
Cranial Window ◽  
Arterial Blood ◽  
The Brain

Cerebral arterioles have been regarded as the primary sites of autoregulatory responses, whereas the role of large arteries in the cerebral autoregulation is poorly understood. The goal of this study was to determine in vivo whether the basilar artery and its primary branches act as resistance vessels under hypotensive conditions by simultaneously measuring their diameters and local brain stem blood flow with laser-Doppler flowmetry. In 10 anesthetized rats, blood flow to the brain stem was well maintained during stepwise hemorrhagic hypotension when mean arterial blood pressure fell from 116 +/- 3 to 50 mmHg and decreased gradually between 50 and 30 mmHg. Diameter of the basilar artery (n = 10) and its large branches (n = 22), measured through an open cranial window, increased by 10% from the baseline value at 50 mmHg and reached their maximum at 30 mmHg (314 +/- 9 from 244 +/- 6 mum, and 149 +/- 4 from 117 +/- 3 mum, respectively). Small branches (n = 15) dilated to a larger extent compared with the larger arteries throughout hypotension and reached the maximum at 30 mmHg (69 +/- 3 from 48 +/- 2 mum). Below 30 mmHg, there was a steep fall in blood flow and reduction in diameter of all-sized arteries. Thus small vessels contribute to reductions in cerebrovascular resistance throughout the entire autoregulatory-range in the brain stem circulation. Large arteries, such as the basilar artery and its branches, also contribute to reductions in cerebrovascular resistance around the lower limits of cerebral blood flow autoregulation and may thus play a significant role in maintaining blood flow to the brain stem during severe systemic hypotension.

scholarly journals Assessment of informative value of effective cerebral blood flow calculation technique according to 99mTc-HMPAO polyphase scintigraphy data

2021 ◽  
Vol 29 (2) ◽  
pp. 62-75
Author(s):  
N. A. Nikolov ◽  
T. H. Novikova ◽  
S. S. Makeуev
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Single Photon ◽  
Neuropsychological Testing ◽  
Photon Emission ◽  
Emission Computed Tomography ◽  
Group A ◽  
Group B ◽  
The Brain ◽  
99Mtc Hmpao

Background. According to single-photon emission computed tomography (SPECT) data, the most common technique to calculate volume cerebral blood flow (VCBF) is N.A. Lassen method. Following it, VCBF in different segments of the brain is assessed in comparison with blood flow in the cerebellum, where it is considered to be constant. However, this approach does not take into account that in some pathologies, in particular, injuries, occlusions of blood vessels, VCBF of the cerebellum also does change. Therefore, an original technique of calculating regional VCBF based on polyphase scintigraphy has been developed, which will make it possible to make a more accurate assessment of the effective perfusion of the brain. Purpose – to evaluate the clinical informative value of the developed technique for calculating effective cerebral blood flow according to 99mTc-HMPAO (hexamethylpropyleneaminoxime) polyphase brain scintigraphy data. Materials and methods. The study is focused on analyzing two groups of patients: Group A represented by patients with signs of chronic cerebral ischemia and Group B enrolling patients in the interim and long term of explosive minor brain injury (n=22). Group A patients were divided into two subgroups, depending on the presence of structural and hemodynamic changes in the vertebral arteries (VA) according to ultrasound (US) of the major vessels of the brain. I-A subgroup (n=13) was made up by those patients who had structural lesions of the vertebrobasilar basin; II-A (n=27) patients had no relevant signs. All patients underwent a comprehensive clinical examination including neuropsychological testing, ultrasound of major vessels, magnetic resonance imaging, single-photon emission computed tomography (SPECT). Effective volume cerebral blood flow (VCBF), according to the SPECT data, was calculated based on the original technique (VCBFSB). VCBFSB values were compared with the SPECT data using N.A. Lassen (VCBFLassen) method and the ultrasound data. Results and discussion. Analysing the data of the groups of patients with hemodynamic impairment in the vertebro-basilar basin shows that, according to the scintigraphy of VCBF, I-A group patients differ from II-A group on average 1.82± 0.06 times the amount for CBFSB and 0.95± 0.04 for CBFLassen. The total mean blood flow   in   the   carotid   and   vertebral   arteries   of I-A group patients was 748.19±198.42 mL/min, II-A group patients – 1112.23±63.71 mL/min. Comparing the mean values of the hemodynamic parameters of the brain of Group B patients with the data of Group II-A patients, VCBFSB was 1.33±0.25-fold decreased, while CBFLassen showed 1.03±0.14-fold decrease of perfusion (in total average blood flow of vertebral and carotid arteries according to US of Group B – 1760±580 ml/min). Conclusions. Preliminary clinical studies, using the developed technique for calculating volume cerebral blood flow according to 99mTc-HMPAO scintigraphy data with the corresponding software, showed a rather high sensitivity in assessing VCBF in case of pathological changes in the brain, especially, in occlusion of the major vessels of the brain and contusions resulting from battle trauma, whereas N.A. Lassen method was insufficiently informative. The regression analysis of US data, SPECT data and neuropsychological testing shows clear linear correlation relationships, but they do also differ in sign depending on the diagnosis and the degree of pathological changes.

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