Search results for "Cerebral blood flow."
showing 10 items of 138 documents
Effects of levosimendan on hemodynamics, local cerebral blood flow, neuronal injury, and neuroinflammation after asphyctic cardiac arrest in rats.
2014
Despite advances in cardiac arrest treatment, high mortality and morbidity rates after successful cardiopulmonary resuscitation are still a major clinical relevant problem. The post cardiac arrest syndrome subsumes myocardial dysfunction, impaired microcirculation, systemic inflammatory response, and neurological impairment. The calcium-sensitizer levosimendan was able to improve myocardial function and initial resuscitation success after experimental cardiac arrest/cardiopulmonary resuscitation. We hypothesized that levosimendan exerts beneficial effects on cerebral blood flow, neuronal injury, neurological outcome, and inflammation 24 hours after experimental cardiac arrest/cardiopulmonar…
Brain BDNF Levels Elevation Induced by Physical Training is Reduced after Unilateral Common Carotid Artery Occlusion in Rats
2014
International audience; We investigated the contribution of blood flow elevation in the cerebrovasculature to physical training-induced brain-derived neurotrophic factor (BDNF) levels elevation in the brain. Brain-derived neurotrophic factor protein levels were measured in the motor cortex 24 h after the last session of a forced treadmill walking (30 minutes a day, 18 m/minute for 7 consecutive days). Unilateral common carotid artery occlusion and modulation of exercise intensity (0 versus -10% inclination of the treadmill) were used as strategies to reduce the (normal) elevation of flow in the cerebrovasculature occurring during exercise. Administration of N-nitro-L-arginine methyl ester (…
A new model of thromboembolic stroke in the posterior circulation of the rat
2006
The prognosis of vertebrobasilar occlusion is grave and therapeutic options are limited. The aim of the present study was to develop a new model of embolic hindbrain ischemia in the rat that closely resembles the clinical situation and that can be used to study pathophysiology and treatment options. After thoracotomy in 20 male Wistar rats, 15 animals received an injection of in vitro prepared autologous blood clots into the left vertebral artery. Five animals without clot injection served as controls. Neurological deficits were assessed in all animals 2 h after embolism. After 2 h, five animals were sacrificed to measure cerebral blood flow (CBF) by iodo-antipyridine autoradiography, and t…
Significance of resting and stimulated cerebral blood flow for predicting the risk of hemodynamic cerebral ischemia in a model of chronic hemodynamic…
2000
OBJECTIVE: It has been postulated that patients with a compromised cerebrovascular reserve capacity (RC), defined as cerebral blood flow (CBF) response to acetazolamide (ACZ) (by percent), are at higher risk for ischemic stroke. The value of CBF and RC for predicting the risk of hemodynamically induced impairment of cerebral function is examined. METHODS: Both common carotid arteries were occluded in 22 Wistar-Kyoto rats. Thirty-one days later, mean arterial blood pressure was reduced to 40 mm Hg for 30 minutes. Laser Doppler scanning of CBF at resting conditions and after intraperitoneal administration of ACZ (0.1 mg/g body weight) was performed 30 minutes and 28 days after occlusion as we…
On the number of measurement sites required to assess regional cerebral blood flow by laser-Doppler scanning during cerebral ischemia and reperfusion.
2001
The aim of this study was to determine whether the number of measurement sites affected the precision of regional cerebral blood flow (CBF) assessment by Laser-Doppler (LD). A simulation study was applied based on data obtained by scanning the cortex in 25 rats during baseline conditions, 15 min global cerebral ischemia and reperfusion. Random samples were repeatedly collected from 1 to 100 locations and deviations from the median of the entire CBF data pool (800 locations) were determined. Single location CBF measurements missed the true median by 24.8+/-2.2 LD-units (baseline conditions, n=100 simulations, mean+/-SEM), 2.7+/-0.6 LD-units (ischemia), and 31.9+/-2.4 LD-units (30th min reper…
The neuroprotective effect of lactate is not due to improved glutamate uptake after controlled cortical impact in rats.
2012
For many years lactate was considered to be a waste product of glycolysis. Data are accumulating that suggest that lactate is an important energy substrate for neurons during activation. In severe traumatic brain injury (TBI) glutamate release and ischemic cerebral blood flow (CBF) are major factors for a mismatch between energy demand and supply and for neuronal cell death. Although ATP and behavior could be improved by lactate treatment after TBI, no histological correlate nor any linkage to better astrocytic glutamate uptake or CBF as possible mechanisms have been described. We subjected male rats to a controlled cortical impact (CCI; 5 m/sec, 2.5 mm). To study the effects of lactate tre…
Administration of transforming growth factor-α reduces infarct volume after transient focal cerebral ischemia in the rat
2001
Growth factors promote cell growth and survival and protect the brain from developing injury after ischemia. In this article, the authors examined whether transforming growth factor-α (TGF-α was protective in transient focal ischemia and whether alteration of cerebral circulation was involved. Rats received intraventricular TGF-α (50 ng, either split into 2 doses given 30 minutes before and 30 minutes after middle cerebral artery occlusion (MCAO), or 1 dose given 30 minutes after MCAO) or vehicle. Rats were subjected to 1-hour intraluminal MCAO and cerebral blood flow was recorded continuously by laser-Doppler flowmetry. Infarct volume was measured 1 and 4 days later. The effects of TGF-α o…
Impaired cerebrovascular autoregulation in patients with severe sepsis and sepsis-associated delirium
2012
Introduction Sepsis-associated delirium (SAD) increases morbidity in septic patients and, therefore, factors contributing to SAD should be further characterized. One possible mechanism might be the impairment of cerebrovascular autoregulation (AR) by sepsis, leading to cerebral hypo- or hyperperfusion in these haemodynamically unstable patients. Therefore, the present study investigates the relationship between the incidence of SAD and the status of AR during sepsis. Methods Cerebral blood flow velocity was measured using transcranial Doppler sonography and was correlated with the invasive arterial blood pressure curve to calculate the index of AR Mx (Mx>0.3 indicates impaired AR). Mx was m…
Effects of Cortical Spreading Depression on Cortical Blood Flow, Impedance, DC Potential, and Infarct Size in a Rat Venous Infarct Model
2000
A cortical venous infarction model has been evaluated as to the degree of regional flow reduction and by studying effects of cortical spreading depression (CSD). Two adjacent cortical veins were occluded photochemically with rose bengal and fiberoptic illumination. Seven rats served to demonstrate effects on regional cortical blood flow using laser Doppler scanning. In 36 rats local CBF, DC potential, and brain tissue impedance were measured continuously for 75 min after vein occlusion. No, 3, or 10 CSD waves were induced by potassium chloride injection during the initial 75 min. Rats were compared for spontaneous CSDs; baseline local CBF, CBF, and impedance response to CSD; and infarct vol…
Postischemic application of lipid peroxidation inhibitor U-101033E reduces neuronal damage after global cerebral ischemia in rats.
1998
Background and Purpose —The lipid peroxidation inhibitor U-101033E was examined for effects on cerebral blood flow (CBF), cortical tissue hemoglobin oxygen saturation (HbS o 2 ), and neuronal damage. Methods —Fifteen minutes of global cerebral ischemia was induced by two-vessel occlusion and hypobaric hypotension. Wistar rats (n=25) were randomized to receive vehicle (n=9) or 40 mg/kg U-101033E (n=9) intraperitoneally during 2 hours of reperfusion. A sham group (n=7) had neither ischemia nor therapy. Histology was evaluated 7 days after ischemia. Results —During late hyperperfusion (at 17 minutes), vehicle-treated animals had a higher ( P =0.044) cortical tissue HbS o 2 (72.0±1.4%) than di…