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1

Enhanced microdialysis of neuropeptides

100%
Pettersson A., Markides K., Bergquist J.
Acta Biochimica Polonica
|
2001
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tom 48
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nr 4
An enhanced microdialysis method for neuropeptides is described and some prelimi­nary results of this novel approach are presented. The enhancement is achieved by adding a vehicle (solid support) to the perfusion fluid in order to increase the diffusion coefficient across the membrane and efficiently transport the analytes towards the de­tector. The microdialysis samples are desalted and then analyzed on an electrospray ionization orthogonal time-of-flight mass spectrometer. The preliminary results show major increase in signal when comparing this new approach of microdialysis with or­dinary microdialysis.
2
Content available remote

Involvement of the histaminergic system in cytidine 5'-diphosphocholine-induced reversal of critical haemorrhagic hypotension in rats

72%
Jochem J., Savci V., Filiz N., Rybus-Kalinowska B., Fogel W. A., Yalcin M.
Journal of Physiology and Pharmacology
|
2010
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tom 61
|
nr 1
37-43
Cytidine 5’-diphosphocholine (CDP-choline) is an endogenously synthesized mononucleotide which exerts a variety of physiological effects by altering central cholinergic transmission. Administered intracerebroventricularly (i.c.v.) or intravenously, it reverses haemorrhagic hypotension in rats, apparently by the activation of central cholinergic receptors. The study was undertaken to investigate the involvement of the central histaminergic system in CDP-choline-mediated reversal of haemorrhagic hypotension. Experiments were carried out in male ketamine/xylazine-anaesthetised Wistar rats subjected to haemorrhagic hypotension of 20-26 mmHg. CDP-choline (2 µmol; i.c.v.) administered at 5 min of critical hypotension produced a long-lasting pressor effect with increases in mean arterial pressure (MAP), heart rate (HR), and renal, hindquarters and mesenteric blood flows, resulting in a 100% survival at 2 h. The action was accompanied by approximately a 26% increase in extracellular histamine concentration at the posterior hypothalamus, as measured by microdialysis. Cardiovascular effects mediated by CDP-choline were almost completely blocked by pretreatment with H1 receptor antagonist chlorpheniramine (50 nmol; i.c.v.), but not with H2 receptor blocker ranitidine (25 nmol; icv) or H3/H4 receptor antagonist thioperamide (50 nmol; i.c.v.). In conclusion, the present results show that the central histaminergic system, through the activation of H1 histaminergic receptors, is involved in CDP-choline-induced resuscitating effect in haemorrhage-shocked rats.
3
Content available remote

Intraperitoneal zinc administration increases extracellular zinc in the rat prefrontal cortex

72%
Opoka W., Sowa-Kucma M., Kowalska M., Bas B., Golembiowska K., Nowak G.
Journal of Physiology and Pharmacology
|
2008
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tom 59
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nr 3
477-487
Single administration of zinc evokes pharmacological behavioral effects in rodents, while no brain zinc alterations were detected. The aim of the present study was to examine the effect of a single zinc hydroaspartate intraperitoneal (ip) administration on the extracellular (synaptic) zinc concentration in the rat prefrontal cortex. We used anodic stripping voltammetric (ASV) method of zinc determination in microdialysate, which assays the extracellular zinc concentration. We report that acute (65 mg/kg) zinc hydroaspartate administration (ip) increases the extracellular zinc by 48% in the rat prefrontal cortex. These data for the first time demonstrate: 1) utility of ASV zinc detection in brain microdialysates and 2) that single ip zinc administration increases brain (cortical) extracellular zinc pool. The results indicate zinc-induced fast brain penetration and may explain its rapid pharmacological effects.
4

Microdialysis of the brain structures: application in behavioral research on vasopressin and oxytocin

72%
Orlowska-Majdak M.
Acta Neurobiologiae Experimentalis
|
2004
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tom 64
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nr 2
5
Content available remote

Hippocampal vasopressin (AVP) dialysis and the conditioned eyelid reflex in rabbits

72%
Orlowska-Majdak M., Kolodziejski P., Traczyk W. Z.
Journal of Physiology and Pharmacology
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2001
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tom 52
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nr 4,2
The role of arginine vasopressin (AVP) dialyzed into the hippocampus or caudate nucleus as the reference structure in the acquisition and extinction of the conditioned eyelid reflex in rabbit was investigated. Phonopneumatic stimulator was used for the generation of conditioned and unconditioned stimuli, and for control of the recorder. Opto-electronic sensor transduced the behavioral responses. Microdialysis probes were chronically implanted into the brain structures. AVP was dialyzed into the brain structures during the extinction procedure. Restraining of the process of extinction was shown during AVP dialysis through the hippocampus and caudate nucleus but the effect in hippocampus was stronger and longer lasting than in caudate nucleus. The influence of AVP dialyzed through the hippocampus on the course of acquisition was biphasic. Some insignificant improvement of learning was observed at the beginning of training and then compensatory, significant restraining of learning. After AVP dialysis through the caudate nucleus only the late, insignificant tendency to improve learning was shown. The effects of AVP were dose-dependent in inversely proportional manner and long-term in nature, especially the effects in hippocampus.
6

NMDA receptors and nitric oxide regulate prostaglandin D2 synthesis in the rabbit hippocampus in vivo

72%
Lazarewicz J. W., Salinska E., Stafiej A., Ziembowicz A., Zieminska E.
Acta Neurobiologiae Experimentalis
|
2000
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tom 60
|
nr 4
The aim of this in vivo microdialysis study was to characterise the regulation of prostaglandin D2 (PgD2) synthesis by NMDA receptors in the rabbit hippocampus in relation to changes in extracellular Ca concentration ([Ca ]e) and nitric oxide (NO) levels. Samples of dialysate were analysed for changes in PgD2 concentration, in [Ca ]e and in the level of NO. The results demonstrated that a 20-min pulse application of 0.1 - 2.5 mM NMDA via a microdialysis probe induced a prolonged stimulation of PgD2 release that was sensitive to competitive NMDA receptor antagonists. An inhibitor of voltage-sensitive Na+ channels, tetrodotoxin, did not influence this effect but significantly suppressed basal PgD2 production, whereas a NOS inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME), prevented NMDA-evoked NO release and inhibited NMDA-induced PgD2 release in an L-arginine-sensitive manner. NO donors, S-nitroso-N-acetylpenicillamine and sodium nitroprusside, stimulated PgD2 release. NMDA-evoked decrease in [Ca2+]e was insensitive to TTX and L-NAME. These results demonstrate an in vivo NMDA receptor-mediated modulation of PgD2 synthesis in the brain, in which NO participates.
7
Content available remote

Effect of ketanserin and amphetamine on nigrostriatal neurotransmission and reactive oxygen species in Parkinsonian rats. In vivo microdialysis study

72%
Nowak P., Szczerbak G., Biedka I., Drosik M., Kostrzewa R. M., Brus R.
Journal of Physiology and Pharmacology
|
2006
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tom 57
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nr 4
5-HT2A/2C receptors are one of the most important in controlling basal ganglia outputs. In rodent models of Parkinson's disease (PD) blockade of these receptors increases locomotion and enhances the actions of dopamine (DA) replacement therapy. Moreover, previously we established that 5-HT2A/2C antagonist attenuate DA D1 agonist mediated vacuous chewing movements (VCMs) which are considered as an animal representation of human dyskinesia. These findings implicate 5-HT neuronal phenotypes in basal ganglia pathology, and promote 5-HT2 antagonists as a rational treatment approach for dyskinesia that is prominent in most instances of PD replacement therapy. In the current study we determined whether ketanserin (KET) and/or amphetamine (AMPH) affected dopaminergic neurotranssmision in intact and fully DA-denervated rats. Moreover, we looked into extraneuronal content of HO. of the neostriatum after AMPH and/or KET injection, assessed by HPLC analysis of dihydroxybenzoic acids (2,3- and 2, 5-DHBA) - spin trap products of salicylate. Findings from the present study demonstrated that there are no substantial differences in extraneuronal HO. generation in the neostriatum between control and parkinsonian rats. KET did not affect DA release in the fully DA-denervated rat's neostriatum and also did not enhance HO. production. As 5-HT2A/2C receptor-mediated transmission might prove usefulness not only in addressing motor complications of PD patients (dyskinesia) but also in addressing non-motor problems such depression and/or L-DOPA evoked psychosis, the findings from the current study showed that the use of 5-HT2A/2C receptor antagonists in Parkinson's disease does not impend the neostriatal neuropil to be damaged by these drugs. We concluded that 5-HT2A/2C receptor antagonists may provide an attractive non-dopaminergic target for improving therapies for some basal ganglia disorders.
8
Content available remote

Studies of phosphodiesterase effects on adipose tissue metabolism in obese subjects by the microdialysis technique

72%
Flechtner-Mors M., Jenkinson C. P., Alt A., Biesalski H. K., Adler G., Ditschuneit H. H.
Journal of Physiology and Pharmacology
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2005
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tom 56
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nr 3
The effect of non-selective (theophylline) inhibition of cyclic AMP breakdown on norepinephrine stimulated lipolysis rate was investigated in subcutaneous adipose tissue of obese subjects. In addition, changes in interstitial glucose and lactate concentration were assessed by means of the microdialysis technique. The interaction of endogenous released insulin and theophylline on adipocyte metabolism was determined. Theophylline and norepinephrine alone increased glycerol outflow significantly. When both agents were perfused in combination, interstitial glycerol concentration increased further. The enhanced glycerol level due to theophylline application was slightly decreased by insulin. In the presence of theophylline, extracellular glucose concentration increased, in contrast to the catecholamine. Norepinephrine decreased interstitial glucose level. When both drugs were added in combination, the level of interstitial glucose increased to about 1 mM, greater than with theophylline alone. With each intervention, lactate was synthesized. Local adipose tissue blood flow was increased by theophylline and theophylline plus norepinephrine. In conclusion, post-receptor mechanisms increased norepinephrine maximal stimulated lipolysis rate in subcutaneous adipose tissue. Glucose uptake was inhibited by the non-specific inhibitor of phosphodiesterase. The effect of insulin on inhibition of lipolysis was modest but sustained in the presence of high theophylline (10-4 M) concentration. Phosphodiesterase activity may be relatively low in obese subjects in comparison with lean subjects. In lean subjects theophylline caused a transient reversal of the antilipolytic effect of insulin.
9
Content available remote

Effect of venlafaxine and nicotine on the level of neurotransmitters and their metabolites in rat brains

58%
Czubak A., Nowakowska E., Golembiowska K., Kus K., Burda K., Metelska J.
Journal of Physiology and Pharmacology
|
2010
|
tom 61
|
nr 3
339-346
Nicotine (NIC) and venlafaxine (VEN) have been proved to exert antidepressant activity in both human and animals. The effect of antidepressant doses of NIC and VEN (our previous results) on noradrenergic (NA), dopaminergic (DA), serotoninergic (5-HT) neurotransmitters and their metabolites: DOPAC, HVA and 5-HIAA in rats’ hippocampus in freely moving rats were determined by microdialysis technique and HPLC method. Both drugs release 5-HT and NA, but VEN to a greater degree. DA level was affected only by VEN, however NIC extended the response of the DA system on VEN’s effect. Combined administration of drugs caused the greatest changes in the 5-HT system. Both drugs contributed to reduction in neurotransmitter biotransformation.
10

Role of calcium in glutamate-mediated toxicity ; mechanisms of calcium fluxes in rabbit hippocampus in vivo investigated with microdialysis

58%
Lazarewicz J. W., Salinska E.
Acta Neurobiologiae Experimentalis
|
1993
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tom 53
|
nr 1
11

Glycine enhances extracellular 45Ca2 response to NMDA application investigated with microdialysis of rabbit hippocampus in vivo

58%
Lazarewicz J. W., Salinska E., Puka M.
Acta Neurobiologiae Experimentalis
|
1992
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tom 52
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nr 2
12

N-methyl-D-aspartate - induced 45Ca2+ release from pre-labelled adult rat hippocampus in vivo

58%
Lazarewicz J. W., Rybkowski W., Puka-Sundvall M., Gadamski R., Hagberg H.
Acta Neurobiologiae Experimentalis
|
1995
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tom 55
|
nr 4
13
Content available remote

7-nitroindazole enhances amphetamine-evoked dopamine release in rat striatum. An in vivo microdialysis and voltammetric study

58%
Nowak P., Brus R., Oswiecimska J., Sokola A., Kostrzewa R. M.
Journal of Physiology and Pharmacology
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2002
|
tom 53
|
nr 2
The intracellular second messenger nitric oxide (NO) is implicated in a variety of physiological functions, including release and uptake of dopamine (DA). In the described study, in vivo microdialysis and differential pulse voltammetric techniques were used to determine the involvement of NO in release of DA and its metabolites (dihydroxyphenylalanine, DOPAC; homovanillic acid, HVA) in neostriatum of freely moving rats. While the NO donor molsidomine (30.0 mg/kg; MOLS) and neuronal NO synthase- (nNOS-) inhbitor 7-nitroindazole (10.0 mg/kg; 7-NI) had no effect on the basal in vivo microdialysate level of DA, 7-NI specifically enhanced D,L-amphetamine- (1.0 mg/kg i.p.; AMPH) evoked release of DA. Basal or AMPH effects on DOPAC and HVA levels were not influenced by MOLS or 7-NI. Findings indicate that nitrergic systems have an important role in mediating effects of AMPH on dopaminergic systems.
14

Effects of caffeine on NMDA-evoked 45 Ca2 release in the rat dentate gyrus in vivo

51%
Alaraj M., Kosinska I., Lazarewicz J. W.
Acta Neurobiologiae Experimentalis
|
1998
|
tom 58
|
nr 4
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