The effect of ozagrel, a selective thromboxane A(2) (TXA(2)) synthetase inhibitor, on the obstruction after cerebral ischemia-reperfusion was studied in experimental animal models. The reduced spontaneously locomotor activity and the obstruction of motor coordination were improved by the administration of ozagrel in the conscious cerebral ischemia-reperfusion mouse model. Ozagrel suppressed ...

Experiments compared the hemispheric neural damage resulting from global hemispheric hypoxic ischemia (GHHI, ligation of right common carotid artery plus 35 min of 12% O2) in groups of anesthetized, male Long Evans rats, 9-10 weeks of age, kept at 37 degrees C, and previously given an intracerebroventricular (i.c.v., 2.5 microl) ...

The aim of this study was to examine the inter-relation between the hemodynamic events, energy metabolism, extracellular potassium and electrical activity during the acute phase of transient ischemia in the gerbil brain. It has already been shown that partial ischemia in the gerbil brain causes changes in the blood flow, ...

The topographic reperfusion pattern of the femoral head after critical ischemia has not yet been investigated. We determined the blood flow of the porcine hip regions with the femoral head epiphysis divided into 24 subregions by the tracer microsphere technique. Blood flow was measured under steady-state conditions, at the end ...

Prolonged cerebral hypothermia is neuroprotective if started within a few hours of hypoxia-ischemia. However, delayed seizure activity is one of the major clinical indicators of an adverse prognosis after perinatal asphyxia. The aim of this study was to determine whether head cooling delayed until after the onset of postasphyxial seizures ...

RATIONALE AND OBJECTIVES: The authors attempted to determine whether the T2 relaxation time of superior mesenteric vein (SMV) blood would decrease in patients with chronic mesenteric ischemia after a meal. MATERIALS AND METHODS: Thirty-two patients without chronic mesenteric ischemia and eight patients with symptomatic chronic mesenteric ischemia underwent magnetic resonance ...

The total, safe, time available for operating during tourniquet ischaemia is thought to be prolonged by short, intervening episodes of reperfusion. However, animal experiments have suggested that this may cause a reduction of the postischaemic reperfusion injury. The purpose of the present study was to investigate the effect on final ...

SPECT using 99mTc-hexamethyl propyleneamine oxime (HMPAO) mainly reflects regional cerebral blood flow, however metabolic abnormalities also affect the retention of 99mTc-HMPAO. METHODS: To rule out any flow factor, a test-tube model was used to evaluate the effects of metabolic alterations both on intracellular trapping of 99mTc-HMPAO and on extracellular glutamate ...

AIM: To study the protective effect of dl-3-n-butylphthalide (NBP) on blood-brain barrier (BBB) damage induced by reperfusion following focal cerebral ischemia. METHODS: Focal cerebral ischemia in rats was performed by inserting a nylon suture into intracranial segment of internal carotid artery to block the origin of middle cerebral artery and ...

The effect of induced hypertension treatment on cerebral ischemia is still controversial. We investigated the preferred blood pressure manipulation level and pressor agent required to reduce cerebral ischemic injury following transient forebrain ischemia induced by bilateral occlusion of the common carotid arteries in anesthetized gerbils. Following 60-min cerebral ischemia, we ...

Gravity and other physical forces (e.g., shear stress or mechanical stretch) will affect organ and cellular function, e.g., blood flow distribution, gas exchange, alveolar size and mechanical stresses within the lung. Microgravity produced marked alterations in lung blood flow and ventilation distribution while hypergravity exaggerated the regional differences in lung ...

OBJECT: Recently, several studies have demonstrated that hypothermia has a beneficial effect on clinical outcome; however, it is difficult to determine the appropriate rewarming conditions in clinical use. The purpose of the present study was to examine the influence of rewarming conditions in gerbils with transient forebrain ischemia. METHODS: Ischemia ...

Adenosine, an intercellular messenger that is a product of the metabolism of ATP, plays a major role in neuronal and vascular responses of the retina to alterations in oxygen delivery. Significant changes in adenosine concentration have been measured in the retina during both ischemia and during the subsequent reperfusion period ...

To determine whether myocardial necrosis may occur during postischemic reperfusion, electron microscopy was used to identify morphological features of irreversible injury in myocardial samples taken from anesthetized dogs with 90-min ischemia and 0-, 5-, 90-, or 180-min reperfusion. In samples without detectable collateral blood flow, necrosis was almost complete, whether ...

In a rat model of cardiac arrest and resuscitation, [(14)C]-iodoantipyrene (IAP) autoradiography was used to measure the regional variations in cerebral blood flow 15 and 60 min after reperfusion. The purpose of this study was to investigate the hypothesis that the inhibition of the Na+/H+ antiporter with methyl isobutyl amiloride ...

The mechanisms involved in the castration-induced involution of the ventral prostate (VP) are not fully understood. It was recently reported that castration decreases blood flow in the VP in rats and that this occurs before the apoptotic involution of the organ. However, it is unknown whether a decrease in blood ...

PURPOSE: The purpose of this study is to determine if monitoring urinary bladder PCO2, PO2, and calculated intramucosal pH would be a reliable index of tissue perfusion. MATERIALS AND METHODS: This nonrandomized controlled study was conducted in a laboratory at a university medical center. Eight immature female Yorkshire pigs were ...

Retrograde cerebral perfusion (RCP) has recently been reported to be useful for the repair of aortic arch aneurysms. However, there is a possibility that RCP supplies a limited amount of blood to the brain [1] and ischemia-reperfusion injury may occur after RCP. FR167653 (FR) is characterized as a potent suppressant ...

BACKGROUND AND PURPOSE: Existing methods for the quantitative measurement of the changing cerebral blood flow (CBF) during reperfusion suffer from poor spatial or temporal resolution. The aim of this study was to implement a recently developed MRI technique for quantitative perfusion imaging in a gerbil model of reperfusion. Flow-sensitive alternating ...

The role of endogenous extracellular superoxide dismutase (EC-SOD) was examined in a murine model of transient focal cerebral ischemia. Homozygous EC-SOD deficient (EC-SOD-/-; n = 18) and wild type (EC-SOD+/+; n = 19) littermates were anesthetized with halothane and subjected to 50 min of intraluminal middle cerebral artery occlusion with ...

Alteration of blood-brain barrier (BBB) function occurs in both permanent and temporary cerebral ischemia. Studies in vivo and in vitro have shown that tumor necrosis factor-alpha (TNFalpha) is involved in changes of BBB permeability. However, the relationship between TNFalpha expression and BBB disruption during reperfusion is unclear. The aim of ...

The presence of a hemorheological disturbance must be considered in the pathophysiological and therapeutical approach to vascular diseases, including cerebral diseases. A reduction of blood fluidity, due either to increase of hematocrit (polycythemic hyperviscosity) or of fibrinogen concentration (plasmatic hyperviscosity) or of red cell rigidity (sclerocythemic hyperviscosity) is commonly considered ...

BACKGROUND: Physicians and their patients are greatly concerned about perioperative blood administration. Although isovolemic hemodilution is utilized to decrease the incidence of transfusion, it is unclear at what degree of hemodilution hepatoenteric ischemia and injury occurs. The authors hypothesized that hepatic ischemia, systemic ischemia, and tissue injury would occur during ...

BACKGROUND AND PURPOSE: Apolipoprotein E (apoE) has been found relevant in a variety of central nervous system disorders. This experiment examined the effect of endogenous murine apoE on selective neuronal necrosis resulting from a transient forebrain ischemia insult. METHODS: ApoE deficient (n=16) and wild type (n=17) halothane-anesthetized mice were subjected ...

BACKGROUND: In order to evaluate acute ischemic damage in the small intestine induced by superior mesenteric artery occlusion (SMAO) and subsequent reperfusion, changes in ATP, ADP, and AMP were measured by high-performance liquid chromatography, and changes in tissue blood flow were measured (from the serosal surface) by the laser doppler ...

Temperature plays an important role in determining outcome following both global and focal brain ischemia. After focal ischemia, the degree of infarction decreases with mild hypothermia and increases with mild hyperthermia. In this study, brain extracellular potassium ion activity and local cerebral blood flow were measured in cerebral cortex during ...

OBJECTIVES: To define the mechanical determinants of transmitral flow and the effect of heart rate during regional ischemia. BACKGROUND: Myocardial ischemia changes the transmitral flow velocity pattern due to disease-induced changes in the heart's diastolic properties. METHODS: Regional ischemia was produced in 12 pigs by partially occluding the left anterior ...

OBJECTIVE: Mannitol is used as a treatment for skeletal muscle ischemia/reperfusion (I/R) injury in humans, despite the fact that its effectiveness in vivo is still disputed. The purpose of this study was to determine the efficacy of mannitol in attenuating I/R injury at the microcirculatory level. METHODS: The study was ...

The present study was done to establish whether the secondary cerebral energy failure could be reproduced in the newborn piglet subjected to transient global hypoxia-ischemia, and whether the evolution of secondary cerebral energy failure could be monitored by measuring the changes of Cyt aa3 using NIRS. Fifteen anesthetized, ventilated newborn ...

Both the rise in extracellular glutamate concentration and anoxic depolarization in the rat striatum during 15 min of global ischemia and reperfusion were monitored using glutamate biosensor and direct current potential electrodes, respectively. Cerebral blood flow (CBF) was simultaneously monitored with a glutamate biosensor or a direct current potential electrode. ...

The contribution of the complement system to cerebral ischemic and ischemia/reperfusion injury was examined in a rabbit model of thromboembolic stroke by delivery of an autologous clot embolus to the intracranial circulation via the internal carotid artery. A two-by-two factorial design was employed to study the impact of complement depletion ...

It was the aim of the present study to investigate the influence of Bretschneider's cardioplegia on norepinephrine (NE) release [determined by high pressure liquid chromatography (HPLC) and electrochemical detection] in isolated perfused guinea-pig hearts. The following resulted were noted. (1) Calcium-dependent exocytotic NE release evoked by electrical field stimulation (12 ...

BACKGROUND AND AIMS: Experimental peritonitis causes gut intramucosal acidosis indicating intramucosal ischemia. However, tissue acidosis may reflect other conditions than ischemia. An increased mucosal-arterial Pco2 difference ( Pco2-gap) is suggested to be a more adequate measure of tissue ischemia than intramucosal pH (pHi). This study was performed to elucidate whether ...

Global cerebral ischemia and subsequent reperfusion induce early impairment of the vasodilator responses to hypercapnia and vasoactive substances. Nitric oxide (NO) is involved in the regulation of cerebral blood flow (CBF) in both health and disease. The present study was designed to assess possible changes in the cerebrovascular reactivity to ...

This review will briefly examine evidence supporting the hypothesis that sound causes changes in cochlear blood flow, intracochlear oxygen levels, and the morphology of cochlear blood vessels. A survey of the literature shows that traditional histopathological studies provided such evidence and that decreased cochlear blood flow can be demonstrated and ...

BACKGROUND AND PURPOSE: Macrophage-1 antigen (Mac-1) (CD11b/CD18), a leukocyte beta2 integrin, facilitates neutrophil adhesion, transendothelial migration, phagocytosis, and respiratory burst, all of which may mediate reperfusion-induced injury to ischemic brain tissue in conditions such as stroke. To determine the role of Mac-1 during ischemia and reperfusion in the brain, we ...

A new model of transient global cerebral ischemia in dogs with minimal measures of intervention is described together with a simple scale for evaluation of functional outcome. During pentobarbital anesthesia, a global cerebral ischemia lasting seven minutes was induced by a four-vessel occlusion and a controlled systemic hypotension. The reperfusion ...

Free radical scavengers have been utilized to prevent the consequences of ischemia, however, results do not seem conclusive. In our study we analyzed the blood flow, function, and histology of rat liver tissue after warm liver ischemia, in order to assess the effect of free radicals in liver reperfusion injury. ...

BACKGROUND/AIMS: Bacterial translocation is postulated as a risk factor in the development of a systemic inflammatory response syndrome (SIRS). Research on this topic has focused on the detection of bacteria and endotoxin in blood or mesenteric lymph nodes (MLNs). We investigated whether bacterial translocation occurs beyond the MLNs into the ...

Vascular diseases of the CNS are a major medical, social and economic problem. From the number of causes leading to nervous malfunction and damage, ischemia is most prominent. Thus, neuronal protection from ischemic damage may provide significant preventive and treatment potential. This study was designed to test possible protective effects ...

BACKGROUND: The aim of this study was to determine whether warm reperfusion improves myocardial protection with cardiac troponin I as the criteria for evaluating the adequacy of myocardial protection. METHODS: One hundred five patients undergoing first-time elective coronary bypass surgery were randomized to one of three cardioplegic strategies of either ...

BACKGROUND: Leukocytes rapidly accumulate in the heart early in reperfusion after ischemia, contributing to reperfusion injury. The purpose of this study was to determine whether treatment with the selectin blocker fucoidin (FCN) would attenuate early leukocyte retention in coronary venules and capillaries during low flow reperfusion. METHODS: Isolated rat hearts ...

Transient local anoxia of the cochlea was induced by pressing the labyrinthine artery, and compound action potential (CAP) or endocochlear potential (EP) was measured before and after transient local anoxia ranging from 5 to 60 min using 106 albino guinea pigs. The complete interruption of the cochlear blood flow by ...

Women generally exhibit angina rather than myocardial infarction as the first manifestation of heart disease. Postmenopausal use of hormone replacement therapy, specifically estrogens, is associated with reduced incidence of major cardiac events suggesting estrogen may protect the heart during ischemia. We recently showed that acute administration of conjugated equine estrogens ...

OBJECTIVE: Rapid reperfusion may be injurious to the ischemic lung. Our aim was to confirm that slow reperfusion improves postischemic pulmonary function and to elucidate the ultrastructural changes associated with slow versus rapid reperfusion. METHODS. We used an ex vivo perfused rat lung transplant model to study the effect of ...

The objective of this study was to determine the effects of staged reperfusion on the progressive reduction in coronary blood flow (CBF) and coronary flow reserve during reperfusion and on the infarct size in the canine heart. Fifteen dogs underwent 90 min of left circumflex coronary artery occlusion and 3 ...

To evaluate the involvement of tissue factor (TF) in blood coagulation reflecting injury of the blood vessels induced by reperfusion following ischemic treatment in rat abdominal blood vessels in vivo, both TF expression and prothrombin time (PTT), which is used as a marker of coagulation, were measured after ischemic-reperfusion treatment. ...

OBJECTIVES: We investigated whether intermittent restoration of blood flow just before reperfusion after ischemia could create beneficial effects similar to ischemic preconditioning, which involves intermittent stoppage of blood flow just before ischemia. METHODS: Male Sprague-Dawley rats were prepared with vascular isolated cremaster muscles, then subjected to 4 hours of ischemia ...

Pulmonary edema develops when pulmonary blood flow is interrupted, then restored. Because the lung is not always hypoxic when ischemic, mechanisms of pulmonary ischemia-reperfusion injury are likely to differ from systemic organs, where reactive oxygen species generated during reperfusion mediate organ dysfunction. We previously showed that pulmonary vascular permeability of ...

BACKGROUND: Dynamic changes of myocardial blood flow have been observed after reperfusion of an occluded coronary artery. MCE performed by intracoronary contrast injection can provide an estimate of microvascular flow. We hypothesized that MCE performed using intravenous infusion of a new generation contrast agent and electrocardiogram-gated harmonic imaging would be ...