Effects of indomethacin on brain blood flow, cerebral metabolism, and sagittal sinus prostanoids after hypoxia

1995 ◽  
Vol 269 (4) ◽  
pp. H1450-H1459 ◽  
Author(s):  
M. G. Coyle ◽  
W. Oh ◽  
K. H. Petersson ◽  
B. S. Stonestreet
Keyword(s):  
Blood Flow ◽  
Low Dose ◽  
Cerebral Metabolism ◽  
Brain Regions ◽  
Cerebral Hypoperfusion ◽  
High Dose ◽  
Brain Blood Flow ◽  
Newborn Piglets ◽  
Sagittal Sinus ◽  
Dose Dependent

We tested the hypotheses that during recovery from hypoxia, newborn piglets exhibit a posthypoxic cerebral hyperemia, indomethacin-pretreated piglets exhibit a posthypoxic cerebral hypoperfusion, and that the changes caused by indomethacin are dose dependent and related to the loss of prostanoids. We studied piglets exposed to 40 min of hypoxia after pretreatment with high (5 mg/kg, n = 9) or low (0.3 mg/kg, n = 8) doses of indomethacin or placebo (n = 9) and allowed to recover for 120 min. In the placebo and low-dose pretreatment groups, total and regional brain blood flow increased during hypoxia but returned to baseline 10 min after hypoxia. High-dose indomethacin pretreatment was associated with a posthypoxic hypoperfusion to certain brain regions at 10 min of recovery to values similar to those after indomethacin treatment before the onset of hypoxia. During and after hypoxia, the cerebral metabolic rate of oxygen was preserved in both the placebo and low-dose groups and decreased significantly during hypoxia in the high-dose group. Sagittal sinus prostacyclin was reduced significantly in both indomethacin-treated groups throughout the study. We conclude that a posthypoxic hyperemia is not observed in newborn piglets. This finding was not altered by pretreatment with a therapeutic dose of indomethacin, whereas a pharmacological dose was associated with selective hypoperfusion to certain brain regions both before hypoxia and during recovery from hypoxia.

Effects of indomethacin on brain blood flow and cerebral metabolism in hypoxic newborn piglets

1993 ◽  
Vol 264 (1) ◽  
pp. H141-H149 ◽  
Author(s):  
M. G. Coyle ◽  
W. Oh ◽  
B. S. Stonestreet
Keyword(s):  
Blood Flow ◽  
Glucose Metabolism ◽  
Dose Group ◽  
Low Dose ◽  
Severe Hypoxia ◽  
High Dose Group ◽  
High Dose ◽  
Brain Blood Flow ◽  
Newborn Piglets ◽  
Dose Dependent

We tested the hypotheses that in newborn piglets indomethacin (Indo) pretreatment blunts the hyperemic brain blood flow (BF) and alters the cerebral metabolic responses to hypoxia and that these responses are dose dependent. We studied 23 chronically instrumented piglets exposed to graded hypoxia (O2 content: 7.1-0.4 microM O2/ml) after pretreatment with high (5 mg/kg, n = 8)-or low (0.3 mg/kg, n = 6)-dose Indo or placebo (diluent, n = 9). Total and regional brain BF increased significantly with decreasing O2 content values (P < 0.01) in all three groups. However, the rise in the brain BF curves with decreasing O2 content values was significantly (P < 0.05) lower in the high-compared with the low-dose group in all brain regions with the greatest effect in the caudal regions. Furthermore, the BF curves in the placebo-treated animals were similar to the low-dose group. The cerebral metabolic rate of O2 (CMR(O2)) and glucose metabolism were preserved in the three groups over all hypoxic ranges until severe hypoxia (O2 content < or = 1.1 microM O2/ml) was achieved in the high-dose group, when CMR(O2) decreased (P < 0.05), and glucose metabolism increased (P < 0.05). The mean arterial blood pressure in the high-dose group during severe hypoxia was 45 mmHg (P > 0.05). Although coupling of cerebral BF and CMR(O2) was preserved in the three groups, this association was significantly altered with high-dose pretreatment. We conclude that an attenuation in the hypoxia-induced brain perfusion by Indo is dose dependent. Alterations in CMR(O2) and glucose metabolism are observed with high-dose pretreatment during severe hypoxia, and the responses to hypoxia are similar with placebo and low-dose Indo pretreatment.

Changes in cerebral blood flow, cerebral metabolites, and breathing movements in the sheep fetus following asphyxia produced by occlusion of the umbilical cord

2009 ◽  
Vol 297 (1) ◽  
pp. R60-R69 ◽  
Author(s):  
Edwin B. Yan ◽  
Ana A. Baburamani ◽  
Adrian M. Walker ◽  
David W. Walker
Keyword(s):  
Blood Flow ◽  
Cerebral Cortex ◽  
Umbilical Cord ◽  
Cerebral Metabolism ◽  
Membrane Integrity ◽  
Brain Regions ◽  
Distinct Pattern ◽  
Cerebral Hypoperfusion ◽  
Fetal Sheep ◽  
Sagittal Sinus

Severe global fetal asphyxia, if caused by a brief occlusion of the umbilical cord, results in prolonged cerebral hypoperfusion in fetal sheep. In this study, we sought evidence to support the hypothesis that cerebral hypoperfusion is a consequence of suppressed cerebral metabolism. In the 24 h following complete occlusion of the umbilical cord for 10 min, sagittal sinus blood flow velocity was significantly decreased for up to 12 h. Capillary blood flow, measured using microspheres, decreased at 1 and 5 h after cord occlusion in many brain regions, including cortical gray and white matter. Microdialysis probes implanted in the cerebral cortex revealed an increase in extracellular glucose concentrations in gray matter for 7–8 h postasphyxia, while lactate increased only briefly, suggesting decreased cerebral glucose utilization over this time. Although these data, as well as the concurrent suppression of breathing movements and electrocortical activity, support the concept of hypometabolic hypoperfusion, the significant increase of pyruvate and glycerol concentrations in dialysate fluid obtained from the cerebral cortex at 3–8 h after cord occlusion suggests an eventual loss of membrane integrity. The prolonged increase of breathing movements for many hours suggests loss of the pontine/thalamic control that produces the distinct pattern of fetal breathing movements.

scholarly journals Acute Intravenous Low- and High-Dose Cocaine Reduces Quantitative Global and Regional Cerebral Blood Flow in Recently Abstinent Subjects with Cocaine use Disorder

2005 ◽  
Vol 25 (7) ◽  
pp. 928-936 ◽  
Author(s):  
Bankole A Johnson ◽  
Michael A Dawes ◽  
John D Roache ◽  
Lynda T Wells ◽  
Nassima Ait-Daoud ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Ischemic Stroke ◽  
Time Course ◽  
Low Dose ◽  
Statistical Significance ◽  
Cerebral Hypoperfusion ◽  
High Dose ◽  
Double Blind ◽  
Cocaine Use

Cocaine-induced hypoperfusion, a risk factor for ischemic stroke, has not been fully characterized during experimental drug-taking among individuals with cocaine use disorder. We sought to examine cocaine's dose-dependent, time-related effects on cerebral blood flow. In a double-blind, randomized human laboratory study with a counterbalanced order of drug administration, 31 male and female subjects with cocaine use disorder were divided into two groups receiving either (a) low-dose cocaine (0.325 mg/kg intravenously) or placebo ( N = 15) or (b) high-dose cocaine (0.650 mg/kg intravenously) or placebo ( N = 16). The different dose conditions were administered on test days separated by a rest period of ≥48 h. Cerebral blood flow was assessed quantitatively using H2O15 positron emission tomography. Experimentally administered low- and high-dose cocaine conditions versus their corresponding placebo conditions were associated with global and regional hypoperfusion. The trend for high- versus low-dose cocaine to be associated with greater hypoperfusion achieved statistical significance only for the dopamine-rich sublobar and midbrain regions. Cocaine's hypoperfusion effects were maximal at 8 mins after infusion (i.e., at about the expected peak of intravenous cocaine levels) and had mostly dissipated by 32 mins after infusion. Although hypoperfusion occurred throughout the brain, the left hemispheric dopamine-rich sublobar region was the most severely affected. Cocaine-induced cerebral hypoperfusion is associated with the time course of its pharmacological effects, and dopamine-rich areas, particularly in the left hemisphere, may be most vulnerable. Increasingly larger doses of cocaine may be associated with greater risk for ischemic stroke.

Effects of hypercarbia on autoregulation of brain blood flow and cerebral metabolism in newborn piglets

1995 ◽  
Vol 7 (5) ◽  
pp. 1381 ◽  
Author(s):  
BS Stonestreet ◽  
ES Barefield ◽  
D Piva ◽  
M Goldstein
Keyword(s):  
Blood Flow ◽  
Oxygen Metabolism ◽  
Brain Regions ◽  
Brain Blood Flow ◽  
Cerebral Oxygen Metabolism ◽  
Newborn Piglets ◽  
Arterial Blood ◽  
Regional Brain ◽  
Total Brain ◽  
Blood Pressures

We tested the hypothesis that, in newborn piglets, hypercarbia impairs autoregulation of total and regional brain blood flow at the lower limb of the autoregulatory curve. Cerebral oxygen metabolism was measured in the same piglets to relate changes in metabolism to blood flow. Instrumented hypercarbic (n = 9) and normocarbic (n = 8) newborn piglets exposed to phlebotomy were studied during normotension and graded hypotension with mean arterial blood pressures of 55-41, 40-31 and < 30 mmHg. In the hypercarbic piglets, total brain blood flow decreased (P < 0.01) from the hypercarbic-normotensive value of 187 +/- 15 mliter min-1 100 g-1 to 139 +/- 18, 66 +/- 11 and 34 +/- 6 at mean arterial blood pressures of 55-41, 40-31 and < 30 mmHg, respectively; in the normocarbic piglets, total brain blood flow did not change from the normotensive value (70 +/- 11 mliter min-1 100 g-1) until the mean arterial blood pressure was < 30 mmHg, when brain blood flow had decreased (P < 0.01) to 49 +/- 8 mliter min-1 100 g-1. In the hypercarbic piglets, all brain regions (cerebrum, caudate nucleus, cerebellum, brainstem and medulla) demonstrated similar response patterns to that of total brain blood flow during hypotension. Thus, during hypercarbia, none of the brain regions demonstrated autoregulation. In the normocarbic piglets, cerebral blood flow decreased (P < 0.01) from the normocarbic-normotensive value of 74 +/- 6 mloter min-1 100 g-1 to 51 +/- 8 and 37 +/- 7 at mean arterial blood pressures of 40-31 and < 30 mmHg, respectively, and blood flow to the caudate nucleus, cerebellum and brainstem did not decrease significantly, and in fact increased (P < 0.01) to the medulla during hypotension. Although cerebral oxygen metabolism was compromised in the hypercarbic and normocarbic piglets, the relationship between metabolism and blood flow was altered such that the cerebral metabolic rate of oxygen per unit of blood flow was lower in the hypercarbic than the normocarbic piglets. We conclude that hypercarbia impairs total and regional brain blood flow autoregulation in newborn piglets.

scholarly journals No evidence for direct effects of recombinant human erythropoietin on cerebral blood flow and metabolism in healthy humans

2018 ◽  
Vol 124 (4) ◽  
pp. 1107-1116 ◽  
Author(s):  
Mark Bitsch Vestergaard ◽  
Otto Mølby Henriksen ◽  
Ulrich Lindberg ◽  
Niels Jacob Aachmann-Andersen ◽  
Kristian Lisbjerg ◽  
...  
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Direct Effect ◽  
Low Dose ◽  
Metabolic Response ◽  
Cerebral Metabolism ◽  
Lactate Concentration ◽  
High Dose ◽  
Healthy Humans ◽  
Positron Emission

Erythropoietin (EPO) is expressed in human brain tissue, but its exact role is unknown. EPO may improve the efficiency of oxidative metabolism and has neuroprotective properties against hypoxic injuries in animal models. We aimed to investigate the effect of recombinant human EPO (rHuEPO) administration on healthy cerebral metabolism in humans during normoxia and during metabolic stress by inhalation of 10% O2hypoxic air. Twenty-four healthy men participated in a two-arm double-blind placebo-controlled trial. rHuEPO was administered as a low dose (5,000 IU) over 4 wk ( n = 12) or as a high dose (500 IU·kg body wt−1·day−1) for three consecutive days ( n = 12). Global cerebral blood flow (CBF) and metabolic rate of glucose (CMRglc) were measured with positron emission tomography. CBF, metabolic rate of oxygen ([Formula: see text]), and cerebral lactate concentration were measured by magnetic resonance imaging and spectroscopy. Low-dose treatment increased hemoglobin and was associated with a near-significant decrease in CBF during baseline normoxia. High-dose treatment caused no change in CBF. Neither treatment had an effect on normoxia CMRglc, [Formula: see text], or lactate concentration or an effect on the cerebral metabolic response to inhalation of hypoxic air. In conclusion, the study found no evidence for a direct effect of rHuEPO on cerebral metabolism.NEW & NOTEWORTHY We demonstrate with magnetic resonance imaging and positron emission tomography that administration of erythropoietin does not have a substantial direct effect on healthy human resting cerebral blood flow or effect on cerebral glucose and oxygen metabolism. Also, administration of erythropoietin did not have a direct effect on the metabolic response to acute hypoxic stress in healthy humans, and a suggested neuroprotective effect from erythropoietin is therefore likely not a direct effect of erythropoietin on cerebral metabolism.

The effects of etomidate on cerebral metabolism and blood flow in a canine model for hypoperfusion

1991 ◽  
Vol 74 (2) ◽  
pp. 263-269 ◽  
Author(s):  
R. Tyler Frizzell ◽  
Yves J. Meyer ◽  
D. John Borchers ◽  
Bradley E. Weprin ◽  
Elizabeth C. Allen ◽  
...  
Keyword(s):  
Blood Flow ◽  
Dose Group ◽  
Low Dose ◽  
Cerebral Metabolism ◽  
Oxygen Extraction Fraction ◽  
Oxygen Extraction ◽  
High Dose Group ◽  
High Dose ◽  
Cerebral Oxygen ◽  
The Mean

✓ The effects of etomidate, a nonbarbiturate cerebral metabolic depressant, on cerebral metabolism and blood flow were studied in 29 dogs during cerebral hypoperfusion. Three groups of animals were studied during a 45-minute normotensive and a 30-minute hypotensive period: 10 control animals without etomidate, 11 animals receiving a 0.1-mg/kg etomidate bolus followed by an infusion of 0.05 mg/kg/min etomidate (low-dose group), and eight animals receiving doses of etomidate sufficient to suppress electroencephalographic bursts (high-dose group). The mean arterial pressure fell to similar levels (p < 0.05) during hypotension in all three groups (40 ± 5, 38 ± 3, and 27 ± 6 mm Hg, respectively). The mean cerebral oxygen extraction fraction rose (p < 0.05) from 0.23 ± 0.02 to 0.55 ± 0.08 in the five control animals tested and from 0.33 ± 0.02 to 0.53 ± 0.02 in the seven animals tested in the low-dose group, but did not increase (p > 0.05) in the four animals tested in the high-dose group (0.24 ± 0.03 to 0.23 ± 0.05). Mean cerebral blood flow levels decreased in all groups during hypotension (p < 0.05): 42 ± 3 to 21 ±4 ml/100 gm/min (52% ± 12% decrease) in the five animals tested in the control group, 60 ± 8 to 24 ± 6 ml/100 gm/min (56% ± 13% decrease) in the four animals tested in the low-dose group, and 55 ± 8 to 22 ± 3 ml/100 gm/min (60% ± 4% decrease) in the four animals tested in the high-dose group. In summary, the cerebral oxygen extraction fraction increased in the control animals and low-dose recipients during hypotension, suggesting the presence of threatened cerebral tissue. In contrast, the cerebral oxygen extraction did not change during hypotension when high-dose etomidate was administered. It is concluded that high-dose etomidate may preserve the cerebral metabolic state during hypotension in the present model.

Enlargement of cerebrospinal fluid spaces in long-term benzodiazepine abusers

1987 ◽  
Vol 17 (4) ◽  
pp. 869-873 ◽  
Author(s):  
C. Schmauss ◽  
J.-C. Krieg
Keyword(s):  
Low Dose ◽  
Matched Control ◽  
Control Group ◽  
High Dose ◽  
Withdrawal Therapy ◽  
The Mean ◽  
Dose Dependent ◽  
Dose Dependent Effect ◽  
Age And Sex

SynopsisIn 17 benzodiazepine (BDZ) dependent in-patients a CT scan was performed before initiation of withdrawal therapy. The evaluation of the ventricular to brain ratio (VBR) by standardized and computerized measurements revealed significantly higher mean VBRs for both high-and low-dose BDZ-dependent patients compared to the mean VBR of an age- and sex-matched control group. In addition, the mean VBR of high-dose BDZ-dependent patients (N = 8) was significantly higher than the mean VBR of low-dose BDZ-dependent patients (N = 9). This difference could not be accounted for by the age of the patients or duration of BDZ-dependency and, therefore, suggests a dose-dependent effect of BDZs on the enlargement of internal CSF-spaces. On the other hand, higher values for the width of external CSF-spaces were found to be related to increasing age of the patients and duration of BDZ-dependency.

scholarly journals High dose intravenous aspirin, not low dose intravenous or oral aspirin, inhibits thrombus formation and stabilizes blood flow in experimental coronary vascular injury

1993 ◽  
Vol 21 (2) ◽  
pp. 502-510 ◽  
Author(s):  
Judith K. Mickelson ◽  
Paul T. Hoff ◽  
Jonathon W. Homeister ◽  
Joseph C. Fantone ◽  
Benedict R. Lucchesi
Keyword(s):  
Blood Flow ◽  
Vascular Injury ◽  
Low Dose ◽  
Thrombus Formation ◽  
High Dose ◽  
Oral Aspirin

Hemodynamic effects of recombinant human erythropoietin on the central nervous system after subarachnoid hemorrhage: reduction of microcirculatory impairment and functional deficits in a rabbit model

2008 ◽  
Vol 109 (6) ◽  
pp. 1155-1164 ◽  
Author(s):  
Amanda M. Murphy ◽  
Anargyros Xenocostas ◽  
Pria Pakkiri ◽  
Ting-Yim Lee
Keyword(s):  
Blood Flow ◽  
Cerebral Blood Flow ◽  
Subarachnoid Hemorrhage ◽  
Recombinant Human Erythropoietin ◽  
Low Dose ◽  
Saline Group ◽  
High Dose ◽  
Hemodynamic Effects ◽  
Neurological Outcomes ◽  
Human Erythropoietin

Object The authors investigated the hemodynamic effects of recombinant human erythropoietin (rhEPO) after subarachnoid hemorrhage (SAH) in rabbits. Methods The authors used male New Zealand White rabbits in this study divided into the following groups: SAH plus saline (16 rabbits), SAH plus low-dose rhEPO (16 rabbits; 1500 IU/kg on Day 0 and 500 IU/kg on Days 2 and 4), SAH plus high-dose rhEPO (10 rabbits; 1500 IU/kg on Days 0, 2, 4, and 6), and sham (6 rabbits). Computed tomography perfusion studies and CT angiography were performed for 1 hour after SAH on Day 0, and once each on Days 2, 4, 7, 9, and 16 after SAH. Assessments of neurological function and tissue histology were also performed. Results The mortality rate was significantly lower after rhEPO treatment (12%) than after saline treatment (44%) (p < 0.05). Neurological outcomes in the low-dose and high-dose rhEPO groups were better than in the saline group after SAH (p < 0.05), and the cerebral blood flow in the high-dose rhEPO group was greater than that in the saline group (p < 0.05). The mean transit time was significantly lower on Days 2 and 4 in the low-dose and high-dose rhEPO groups than in the saline group, but increased significantly on Day 7 in both groups (p < 0.05). The hematocrit increased significantly from baseline values in the high-dose and low-dose rhEPO groups on Days 4 and 7, respectively (p < 0.05). Conclusions Treatment with rhEPO after experimental SAH is associated with improved cerebral blood flow and microcirculatory flow as reflected by lower mean transit times. Improved tissue perfusion correlated with reduced mortality and improved neurological outcomes. Further investigation of the impact of increasing hematocrit on hemodynamic changes is needed.

scholarly journals Major Depressive Disorder (MDD) and Antidepressant Medication Are Overrepresented in High-Dose Statin Treatment

2021 ◽  
Vol 8 ◽  
Author(s):  
Leutner Michael ◽  
Matzhold Caspar ◽  
Kautzky Alexander ◽  
Kaleta Michaela ◽  
Thurner Stefan ◽  
...  
Keyword(s):  
Major Depressive Disorder ◽  
Inpatient Care ◽  
Low Dose ◽  
Antidepressant Medication ◽  
Statin Treatment ◽  
High Dose ◽  
Major Depressive ◽  
Dependent Relationship ◽  
Different Types ◽  
Dose Dependent

Objective: To examine the dose-dependent relationship of different types of statins with the occurrence of major depressive disorder (MDD) and prescription of antidepressant medication.Methods: This cross-sectional study used medical claims data for the general Austrian population (n = 7,481,168) to identify all statin-treated patients. We analyzed all patients with MDD undergoing statin treatment and calculated the average defined daily dose for six different types of statins. In a sub-analysis conducted independently of inpatient care, we investigated all patients on antidepressant medication (statin-treated patients: n = 98,913; non-statin-treated patients: n = 789,683). Multivariate logistic regression analyses were conducted to calculate the risk of diagnosed MDD and prescription of antidepressant medication in patients treated with different types of statins and dosages compared to non-statin-treated patients.Results: In this study, there was an overrepresentation of MDD in statin-treated patients when compared to non-statin-treated patients (OR: 1.22, 95% CI: 1.20–1.25). However, there was a dose dependent relationship between statins and diagnosis of MDD. Compared to controls, the ORs of MDD were lower for low-dose statin-treated patients (simvastatin&gt;0– &lt; =10 mg:OR: 0.59, 95% CI: 0.54–0.64; atorvastatin&gt;0– &lt; =10 mg:OR:0.65, 95%CI: 0.59–0.70; rosuvastatin&gt;0– &lt; =10 mg:OR: 0.68, 95% CI: 0.53–0.85). In higher statin dosages there was an overrepresentation of MDD (simvastatin&gt;40– &lt; =60 mg:OR: 2.42, 95% CI: 2.18–2.70, &gt;60–80 mg:OR: 5.27, 95% CI: 4.21–6.60; atorvastatin&gt;40– &lt; =60 mg:OR: 2.71, 95% CI: 1.98–3.72, &gt;60– &lt; =80 mg:OR: 3.73, 95% CI: 2.22–6.28; rosuvastatin&gt;20– &lt; =40 mg:OR: 2.09, 95% CI: 1.31–3.34). The results were confirmed in a sex-specific analysis and in a cohort of patients taking antidepressants, prescribed independently of inpatient care.Conclusions: This study shows that it is important to carefully re-investigate the relationship between statins and MDD. High-dose statin treatment was related to an overrepresentation, low-dose statin treatment to an underrepresentation of MDD.

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