Disease relevance of Microdialysis

• Sixty minutes after the insertion of the microdialysis probes, systemic hypoxia was induced for 30 minutes by having the subjects breathe a mixture of 10.5% O2 in N2 [1].
• In vivo cerebral microdialysis studies revealed that mild hypothermia resulted in a significant reduction of extracellular glutamate concentrations in the brains of rats with ALF (control: 1 [2].
• To test the hypothesis that nuclei of the ventromedial hypothalamus (VMH) play a key role in the detection of counterregulatory responses to hypoglycemia, we delivered the glucopenic agent 2-deoxyglucose via bilaterally placed microdialysis probes into the VMH of conscious, chronically catheterized rats [3].
• Ribonuclease T1 was purified from an Escherichia coli overproducing strain and co-crystallized with adenosine 2'-monophosphate (2'-AMP) by microdialysis against 50% (v/v) 2-methyl-2,4-pentanediol in 20 mM sodium acetate, 2 mM calcium acetate, pH 4 [4].
• The mechanism behind hyperemia in skeletal muscle during insulin-induced hypoglycemia was investigated in 42 anesthetized male Wistar rats using the microdialysis ethanol technique of monitoring nutritive blood flow [5].

Psychiatry related information on Microdialysis

• Given the role of the mesolimbic dopamine (DA) system in the initiation and maintenance of motivated behavior, microdialysis was used to monitor nucleus accumbens (NAC) DA transmission during copulation, sexual satiety, and the reinitiation of sexual behavior [6].
• This study was carried out to analyze the extracellular levels of Met-enkephalin-like material in the nucleus accumbens, a brain structure involved in the effects of opioids on motor activity and reward processes, using microdialysis in awake and freely moving rats, combined with a sensitive radioimmunoassay [7].
• Electroconvulsive shock produces large increases in interstitial concentrations of dopamine in the rat striatum: an in vivo microdialysis study [8].
• Extracellular adenosine in the human brain during sleep and sleep deprivation: an in vivo microdialysis study [9].
• The present study examined using microdialysis whether such increases in DA and 5-HT syntheses are influenced by adrenal hormones, which are also activated following intracranial self-stimulation [10].

High impact information on Microdialysis

• In vivo microdialysis of muscle tissue was used to determine the gradient between plasma and interstitial-fluid glucose concentrations, and open-flow microperfusion was used to determine the concentrations of insulin in interstitial fluid [11].
• In situ microdialysis in bone tissue. Stimulation of prostaglandin E2 release by weight-bearing mechanical loading [12].
• Extracellular fluid (ECF) levels of the catecholamines norepinephrine (NE), dihydroxyphenylglycol (DHPG), methoxyhydroxyphenylglycol (MHPG), and dihydroxyphenylacetic acid (DOPAC) were obtained by microdialysis in the paraventricular nucleus (PVN) of the hypothalamus at baseline and during immobilization (IMMO) [13].
• Both cell types survived implantation into the striatum, expressed TH immunoreactivity, and as assessed by microdialysis 8-9 days after implantation, secreted high amounts of DOPA and/or dopamine into the surrounding host striatum [14].
• Microdialysis probes placed within the vena cava and brain cortex were used to directly compare steady-state, interstitial unbound diazepam levels in both Wistar and genetically analbuminemic rats [15].

Chemical compound and disease context of Microdialysis

• Effect of physiological hyperinsulinemia on blood flow and interstitial glucose concentration in human skeletal muscle and adipose tissue studied by microdialysis [16].
• Using a microdialysis technique, we aimed to estimate in vivo blood flow and interstitial lactate concentrations in the trapezius muscle at rest and during static exercise in patients with chronic tension-type headache and in healthy subjects [17].
• RESULTS: The diabetes-induced decrease in renal oxygen tension, due to augmented oxygen consumption, did not result in manifest hypoxia in either the cortical or the medullary region, as evaluated by microdialysis measurements of purine-based metabolites [18].
• Plasma serotonin levels were recorded before, during, and after photothrombosis by intra-arterial in vivo microdialysis with the probe placed distal to the site of thrombosis [19].
• We tested this hypothesis in the human forearm using microdialysis to estimate interstitial and intravascular levels of adenosine and caffeine withdrawal to potentiate endogenous adenosine and determine its effect on reactive hyperemia [20].

Biological context of Microdialysis

• Finally, microdialysis studies showed that intrastriatal infusion of NMDA increased extracellular glutamate levels to a greater extent in -/- than in +/+ mice, supporting the hypothesis that the mGluR4 subtype is necessary for the maintenance of the homeostasis of extracellular glutamate levels [21].
• Glycerol levels (an index of lipolysis) were measured in m. gastrocnemius and in abdominal adipose tissue using microdialysis [22].
• Glucose uptake (by microdialysis, rGUMD) was calculated by multiplying glucose extraction by regional blood flow [23].
• Using cerebral microdialysis, we measured nonenzymatic hydroxylation of salicylate by HPLC with electrochemical detection in the hippocampus [24].
• Changes in extracellular glycerol concentration and local blood flow were measured in SCAAT during a 45-min exercise bout (50% of heart rate reserve) using a control microdialysis probe and a probe supplemented with the alpha2-AR antagonist phentolamine [25].

Anatomical context of Microdialysis

• The present study investigated the effect in freely moving rats of intravenous cocaine, amphetamine, and morphine on extracellular dopamine concentrations in the nucleus accumbens shell and core by means of microdialysis with vertically implanted concentric probes [26].
• In line with LTP shortening, in vivo microdialysis showed a significant decrease in basal and K(+)-evoked extracellular glutamate levels in the hippocampus of juvenile and adult rats born from WIN-treated dams [27].
• Exposure to the cocaine SDelta significantly increased dopamine efflux in the NAcc and amygdala as measured by intracranial microdialysis in a separate group of rats [28].
• METHODS AND RESULTS: Skeletal muscle interstitial adenosine concentrations were determined by the microdialysis technique, in which 4 semipermeable microdialysis probes were inserted into the vastus lateralis muscle of 6 healthy male subjects and perfused at a rate of 5 microL/min with Ringer's solution [1].
• Microdialysis studies showed that application of orexin A to the TMN increased histamine release from both the medial preoptic area and the frontal cortex by approximately 2-fold over the baseline for 80 to 160 min in a dose-dependent manner [29].

Associations of Microdialysis with chemical compounds

• In conclusion, our data demonstrate that in situ microdialysis is a useful method for studying the PGE2 production in human bone [12].
• We used bilateral intrahippocampal microdialysis to test the hypothesis that an increase in extracellular glutamate may trigger spontaneous seizures [30].
• Hippocampal noradrenaline release after microdialysis and the frequency of abdominal contractions were measured in response to acute colorectal distention [31].
• Microdialysis studies with 5-HT reuptake inhibitors [32].
• Upon intracerebroventricular administration, galanin-(1-16) (10 micrograms/15 microliters) also inhibited the scopolamine (0.3 mg/kg, s.c.)-evoked release of acetylcholine, as studied in vivo by microdialysis [33].

Gene context of Microdialysis

• Next, we demonstrated by simultaneous microdialysis of the suprachiasmatic nucleus and the PVN that AVP measured in PVN dialysates during social defeat was probably of intranuclear origin [34].
• Furthermore, we illustrate that microdialysis is a viable method that may be applied in human breast tissue to detect soluble VEGF in situ released by the tumor [35].
• Quantitative in vivo microdialysis revealed an increase in extracellular dopamine concentration in the striatum of parkin-/- mice [36].
• Blockade of substance P (neurokinin 1) receptors enhances extracellular serotonin when combined with a selective serotonin reuptake inhibitor: an in vivo microdialysis study in mice [37].
• FM (n = 8) and HC (n = 8) underwent a cycle ergometry test of aerobic capacity, a muscle biopsy for determination of nitric oxide synthase (eNOS, nNOS, iNOS) content, and microdialysis for investigation of muscle nutritive blood flow and lactate metabolism [38].

Analytical, diagnostic and therapeutic context of Microdialysis

• In vivo microdialysis was used in conscious rats to investigate the effects of local perfusion with NT on the sensitivity of striatal dopamine D1 and D2 receptors for their selective agonists by monitoring extracellular dopamine, 3,4-dihydroxyphenylacetic acid, homovanilic acid, and gamma-aminobutyric acid levels in the awake unrestrained male rat [39].
• Murine tumors grown in syngeneic hosts or human tumors grown in immunodeficient nu/nu mice were subjected to microdialysis, and adenosine levels in the microdialysate were measured by high-performance liquid chromatography [40].
• In the present brain microdialysis study we have used a chromatographic method (HPLC) enabling the simultaneous measurement of DA, 5-HT, and their main metabolites dihydroxyphenylacetic acid (DOPAC) and 5-hydroxyindoleacetic acid (5-HIAA) [41].
• In vivo microdialysis was used to assess the effects of electrical stimulation of the prefrontal cortex (PFC) on dopamine (DA) release in the nucleus accumbens (NAC) of awake, unrestrained rats [42].
• Probe placement and the source of cholinergic innervation to the vicinity of the microdialysis probe were verified using retrograde tracing combined with ChAT immunohistochemistry [43].

References