Endpoints for Stroke Studies
Yanlin Wang-Fischer in Manual of Stroke Models in Rats, 2008
Evans blue is an anionic dye and is a large molecule closely related to trypan blue. It has been used to measure blood volume because it binds to serum proteins and stays in the circulation for a few hours.78 When it leaves the blood, some of it binds to collagen (its elongated structure favors this), and some is taken into cells, including macrophages and neurons. The dye–protein complex is fluorescent (red emission) and was the first fluorescent tracer of neuronal uptake and retrograde axonal transport. Evans blue can be eliminated from tissue by washing in slightly alkaline water. Evans blue and trypan blue both can be used to determine cell vitality; live cells exclude the dye, dead cells take it up, forming the basis of the trypan blue exclusion test. Evans blue dye has been used for quantitative evaluation of BBB permeability in stroke and in myocardial ischemia.79,80 Infarcted tissue stains blue, but normal tissue does not stain. This technique avoids the costs associated with radioisotope use and is simpler than the [3H] sucrose method since it does not require an integral sample. The only equipment required is a spectrophotometer. However, the Evans blue technique can only produce total permanent values; rate constants cannot be estimated this way.
Functions of the Kidneys and Functional Anatomy
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal in Principles of Physiology for the Anaesthetist, 2020
Approximately two-thirds of body weight is water. A 70-kg male has a total body water content of 42L, divided between the intravascular (3L plasma), interstitial (11L) and intracellular (28L) fluid compartments (the extracellular fluid is the sum of intravascular and interstitial volumes). Total body water can be estimated using dilution techniques with markers that diffuse throughout the total body water compartment, such as isotopically labelled water, using deuterium (2H) or tritium (3H). Markers used to determine the extracellular fluid must cross capillaries but not cell membranes; these include inulin, mannitol, radiosodium, radiochloride and thiosulphate (the latter is the most widely used). The intravascular fluid volume can be determined with a marker that remains within vessels, such as radiolabelled albumin, or the dye Evans blue, which binds to plasma albumin. The interstitial volume cannot be measured directly and is calculated by subtraction of the plasma volume from the extracellular volume.
Renal physiology
Peter Kam, Ian Power, Michael J. Cousins, Philip J. Siddal in Principles of Physiology for the Anaesthetist, 2015
Approximately two-thirds of the body weight is water. A 70-kg male has a total body water content of 42 L, divided between the intravascular (3 L plasma), interstitial (11 L) and intracellular (28 L) fluid compartments (the extracellular fluid is the sum of intravascular and interstitial volumes). Total body water can be estimated using dilution techniques with markers that diffuse throughout the total body water compartment, such as isotopically labelled water, using deuterium (2H) or tritium (3H). Markers used to determine the extracellular fluid must cross capillaries but not cell membranes; these include inulin, mannitol, radiosodium, radiochloride and thiosulphate (the latter is the most widely used). The intravascular fluid volume can be determined with a marker that remains within vessels, such as radiolabelled albumin, or the dye Evans blue, which binds to plasma albumin. The interstitial volume cannot be measured directly and is calculated by subtraction of the plasma volume from the extracellular volume.
The protective effects of lycopus lucidus turcz in diabetic retinopathy and its possible mechanisms
Published in Artificial Cells, Nanomedicine, and Biotechnology, 2019
Jinlu Liu, Sai Bhuvanagiri, Xiaohan Qu
To assess the function of BRB, 2% Evans blue was dissolved in PBS was injected into rats intraperitoneally. Blood was extracted from the left ventricle after 2 h. Subsequently, PBS was injected into the left ventricle to perfuse and eliminate the Evans blue dye in blood vessels thoroughly. Then, the retinas were dissected and the weight was measured after completely drying. Next, the retinas were routinely treated with 120 μl formamide at 70 °C for 18 h for the sake of collecting Evans blue dye. Then, the extract was centrifuged at 10,000 g twice for 1 h at 4 °C. The supernatant was collected to measure the absorbance with a spectrophotometer at 620 nm. The concentration of Evans blue dye in extracts was analysed using an Evans blue standard curve. Each sample was measured three times.
Astragalus injection ameliorates lipopolysaccharide-induced cognitive decline via relieving acute neuroinflammation and BBB damage and upregulating the BDNF-CREB pathway in mice
Published in Pharmaceutical Biology, 2022
Ke Liu, Guoran Wan, Ruhong Jiang, Li Zou, Dong Wan, Huifeng Zhu, Shan Feng
Evans blue is an azo dye that binds to albumin in blood and cannot traverse through normal BBB. Therefore, the fluorescence intensity of Evans blue in the brain reflects the damage status of BBB structure. The mouse brains were conspicuously stained in blue 24 h after 5 days of Astragalus injection treatment, and the whole cerebral cortex was filled with robust fluorescent signals (Figure 6(A)). Astragalus injection markedly attenuated the blue staining in the mouse brains, as reflected by the fluorescent intensity of Evans blue (Figure 6(A)). The ultrastructural changes in BBB were also examined. As shown in the control group, the BBB unit was composed of endothelial cells, basal lamina, pericytes, and astrocyte end feet (Figure 6(B)). After the LPS injury, the basement membrane was disrupted and tight junctions were damaged, in addition to evident swollen astrocyte end feet (Figure 6(B)). However, the basement membrane was preserved, and the tight junctions were restored in the Astragalus injection-treated group (Figure 6(B)).
Pulmonary delivery of resveratrol-β-cyclodextrin inclusion complexes for the prevention of zinc chloride smoke-induced acute lung injury
Published in Drug Delivery, 2022
Wanmei Wang, Yan Liu, Pan Pan, Yueqi Huang, Ting Chen, Tianyu Yuan, Yulong Ma, Guang Han, Jiahuan Li, Yiguang Jin, Fei Xie
The mice were randomly divided into four groups (four each group). All the animal experimental processes were the same as the above pharmacodynamic study until 47 h post-smoke exposure. An Evans blue saline solution (2%, 20 mg/kg) was injected to the mice via tail veins for evaluation of pulmonary vascular permeability. One hour post-injection, the mice were anesthetized with chloral hydrate and the peripheral blood was almost removed out by cutting of the abdominal aorta. The heart and lung were together withdrawn. The cardiopulmonary circulation was flushed with saline until no residual blood in the lung. The lung was departed from the heart and photographed. The left lung was homogenized in formamide and incubated at 37 °C for 24 h. The homogenates were centrifuged (5000×g, 10 min) in a centrifuge (H2-16 KR, Hunan Kecheng Instrument Equipment Co., Ltd., Changsha, China) and the supernatants were collected. The optical densities of samples were measured at 630 nm. The concentrations of Evans blue in the homogenates were calculated according to the standard curve of Evans blue in formamide.
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