Search results for " High pressure liquid"
showing 10 items of 705 documents
Free choline and choline metabolites in rat brain and body fluids: sensitive determination and implications for choline supply to the brain.
1993
In the central nervous system, choline is an essential precursor of choline-containing phospholipids in neurons and glial cells and of acetylcholine in cholinergic neurons. In order to study choline transport and metabolism in the brain, we developed a comprehensive methodical procedure for the analysis of choline and its major metabolites which involves a separation step, selective hydrolysis and subsequent determination of free choline by HPLC and electrochemical detection. In the present paper, we report the levels of choline, acetylcholine, phosphocholine, glycerophosphocholine and choline-containing phospholipids in brain tissue, cerebrospinal fluid and blood plasma of the untreated ra…
Effect of beta-N-oxalylamino-L-alanine on cerebellar cGMP level in vivo.
1993
Beta-N-oxalylamino-L-alanine (BOAA), a non-protein amino acid present in the seeds of Lathyrus Sativus (LS), is one of several neuroactive glutamate analogs reported to stimulate excitatory receptors and, in high concentrations, cause neuronal degeneration. In the present study, the in vivo acute effects of synthetic BOAA and LS seed extract were investigated on rat cerebellar cyclic GMP following intraperitoneal (10-100 mg/kg) or oral (100 mg/kg) administration of subconvulsive doses of toxin. Furthermore, the BOAA content in LS seeds and in the cerebellum of injected rats was determined by high performance liquid chromatograph analysis. A dose- and time-dependent increase of cerebellar cy…
Steady state concentrations of clomipramine and its major metabolite desmethylclomipramine in rat brain and serum after oral administration of clomip…
2000
Twenty male Sprague-Dawley rats received five oral doses of clomipramine 20 mg/kg at 4-h intervals. The animals were decapitated 1, 2, 3, 5 and 12 h after the last dose for determination of clomipramine and desmethylclomipramine in serum and frontal cerebral cortex. Time dependent concentrations of clomipramine and desmethylclomipramine paralleled in serum and brain. Half-lives were similar in serum and brain with 7.8 versus 6.2 h and 5.5 versus 5.0 h for clomipramine and desmethylclomipramine, respectively. Absolute concentrations, however, were markedly higher in brain than in serum - 12.5 fold for clomipramine and 7.4 fold for desmethylclomipramine. The data indicate that serum and brain…
PE-11, a peptide derived from chromogranin B, in the rat eye.
2010
The aim of the study was to investigate the presence and distribution of PE-11, a peptide derived from chromogranin B, in the rat eye. For this purpose, newborn rats were injected with a single dosage of 50mg/kg capsaicin subcutaneously under the neck fold and after three months, particular eye tissues were dissected and the concentration of PE-11-like immunoreactivity was determined by radioimmunoassay. Furthermore, PE-11-like immunoreactivities were characterized in an extract of the rat eye by reversed phase HPLC. Then, the distribution pattern of PE-11 was investigated in the rat eye and rat trigeminal ganglion by immunofluorescence. As a result, PE-11 was present in each tissue of the …
Alzheimer's disease: amino acid levels and brain metabolic status.
2013
Abstract To study brain free amino acids and their relation with dementia we measured, by high-performance liquid chromatography (HPLC), the concentration of eight free amino acids, amines and related compounds. We used temporal cortex (TC) samples obtained from 13 Alzheimer’s disease (AD) patients and an equal number of agematched controls (AC). The patterns of free amino acids, amines and related compounds showed significant quantitative changes in AD conditions with respect to healthy ones. In Alzheimer patients, lower levels of GABA were found in the TC (-57 %). Amino acids glutamate (Glu), and aspartate (Asp) concentrations, also appeared significantly reduced in the TC of AD patients …
Effects of zinc acexamate on blood flow and prostanoid levels in the gastric mucosa of the rat
1989
The effects of the new antiulcer compound zinc acexamate on blood flow and prostanoid levels in the gastric mucosa have been studied. Zinc acexamate (30 and 300 mg/kg) dose-dependently prevents the reduction induced by the perfusion of noradrenaline (3.5 micrograms/kg.min, 30 min) in gastric mucosal blood flow, as measured by 3H-aniline clearance. Zinc acexamate pretreatment also increases the levels of prostaglandin E2 in the gastric mucosa of the rat, both under control conditions and after infusion with noradrenaline. The levels of thromboxane A2 and prostacyclin were not modified by zinc acexamate. These results confirm the importance of microcirculation in pathogenesis and the idea tha…
Environmental enrichment promotes neurogenesis and changes the extracellular concentrations of glutamate and GABA in the hippocampus of aged rats.
2005
The aim of the present study was to investigate the effects of environmental enrichment on the neurogenesis and the extracellular concentrations of glutamate and GABA in the hippocampus of freely moving young and aged rats. Male Wistar rats of 2 (young) and 25 (old) months of age were housed during 8 weeks in an enriched environment; control rats were kept in individual plastic cages during that same period of time. Rats were injected intraperitoneally with bromodeoxyuridine (BrdU; 40 mg/kg; 7 days) during the fourth week of the housing period to detect neurogenesis in the dentate gyrus (DG) of the hippocampus. Rats were sacrified 6 weeks after the last injection of BrdU. During the last we…
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…
The unilateral nigral lesion induces dramatic bilateral modification on rat brain monoamine neurochemistry
2009
6-Hydroxydopamine (6-OHDA) is a neurotoxic compound commonly used to induce dopamine (DA) depletion in the nigrostriatal system, mimicking Parkinson's disease (PD) in animals. The aim of the present study was to evaluate the 7-day effect of unilateral nigral lesion on rat brain monoamine neurochemistry. Five brain regions were examined: the brain stem, cerebellum, hippocampus, striatum, and cortex. 6-OHDA-unilateral lesion dramatically modified DA, serotonin (5-HT) and their metabolites contents in both sides of the different brain nuclei. Furthermore, unilateral 6-OHDA lesion reduced DA and 5-HT contents and produced a robust inversion of their turnover in the nonlesioned side compared to …
Day-night rhythm of acetylcholine in the rat pineal gland
1997
Abstract Using high-performance-liquid-chromatography (HPLC) measurement of acetylcholine, choline acetyltransferase (ChAT) enzyme assay and anti-ChAT immunohistochemistry, we have investigated the expression of the cholinergic system in pineal glands of male rats. Glands procured during the day period (1200 h) contained significant amounts of acetylcholine (0.5 pmol/gland). A similar content was found in pineal glands after a 48 h culture period, i.e. when the intrapineal nerve fibres have degenerated. This strongly indicates that the pinealocytes are the cells which contain acetylcholine. To confirm this conclusion we demonstrate substantial ChAT-like immunoreactivity in pinealocytes. ChA…