Search results for "Acetic Acid"
showing 10 items of 427 documents
Shell/core differences in mu- and delta-opioid receptor modulation of dopamine efflux in nucleus accumbens
2008
The mu- and delta-opioid receptors located at the terminal level in nucleus accumbens are involved in the opiate modulation of dopamine release in this brain area. However, recent studies suggest that the effects of opioid drugs on the core subregion of nucleus accumbens may completely differ from those observed in the shell. We used in vivo microdialysis to simultaneously apply selective mu- and delta-opioid receptor agonists and to measure extracellular levels of dopamine in three subregions of the accumbens, namely shell, core, and the transition zone between them. The regional analysis of these subregions of the accumbens demonstrated that basal levels of dopamine and its metabolites we…
GABA receptors are involved in the modulation of the release of 5-hydroxytryptamine from the vascularly perfused small intestine of the guinea-pig
1989
Isolated small intestinal segments of the guinea-pig were perfused arterially and the release of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) into the portal venous effluent was determined by HPLC with electrochemical detection. Test substances were applied intraarterially. Muscimol (1 microM) time dependently first increased then decreased the release of 5-HT and 5-HIAA. The stimulatory effect was prevented by tetrodotoxin (TTx) or scopolamine, indicating that it was mediated by the release of acetylcholine. Bicuculline concentration dependently decreased (1 microM) or increased (10, 50 microM) the release of 5-HT and 5-HIAA, indicating that endogenous GABA also activ…
[(11)C]PR04.MZ, a promising DAT ligand for low concentration imaging: Synthesis, efficient (11)C-O-methylation and initial small animal PET studies.
2009
PR04.MZ was designed as a highly selective dopamine transporter inhibitor, derived from natural cocaine. Its binding profile indicates that [{sup 11}C]PR04.MZ may be suited as a PET radioligand for the non-invasive exploration of striatal and extrastriatal DAT populations. As a key feature, its structural design facilitates both, labelling with fluorine-18 at its terminally fluorinated butynyl moiety and carbon-11 at its methyl ester function. The present report concerns the efficient [{sup 11}C]MeI mediated synthesis of [{sup 11}C]PR04.MZ from an O-desmethyl precursor trifluoroacetic acid salt with Rb{sub 2}CO{sub 3} in DMF in up to 95 {+-} 5% labelling yield. A preliminary {mu}PET-experim…
Chemical sympathectomy and clorgyline-induced stimulation of rat pineal melatonin synthesis
1989
The response to administration of the specific monoamine oxidase A (MAO-A) blocker clorgyline was investigated in adult male Sprague-Dawley rats which were sympathectomized by injection of the false neurotransmitter 6-hydroxydopamine as newborns. In intact animals which served as controls, the contents of pineal indoles melatonin, serotonin, 5-hydroxytryptophan were augmented, and the content of 5-hydroxyindoleacetic acid decreased 90 min following clorgyline injections when compared to saline receiving rats. Sympathectomized animals exhibited similar responses but these were less pronounced. It is suggested that blocking of the oxidation of both MAO-A substrates, noradrenaline and serotoni…
Assessment of the abuse potential of MDMA in the conditioned place preference paradigm: Role of CB1 receptors
2013
Numerous reports have highlighted the role of the endocannabinoid system in the addictive potential of MDMA (3,4-methylenedioxy-methamphetamine). A previous report showed that CB1 knockout (KOCB1) mice do not acquire MDMA self-administration, despite developing conditioned place preference (CPP). This contradiction could be due to the particular procedure of place conditioning used. The present work compares MDMA-induced CPP in KOCB1 mice using unbiased and biased procedures of place conditioning. In the unbiased procedure, MDMA induced CPP and reinstatement of the extinguished preference in wild type (WT) mice, but not in KOCB1 mice. In contrast, in a biased protocol of CPP, MDMA produced …
Drinking water disinfection by-products during pregnancy and child neuropsychological development in the INMA Spanish cohort study.
2017
Background: Disinfection by-products (DBPs) constitute a complex mixture of prevalent chemicals in drinking water and there is evidence of neurotoxicity for some of them. Objectives: We evaluated the association between estimates of DBP exposure during pregnancy and child neuropsychological outcomes at 1 and 4–5 years of age. Methods: We conducted a population-based mother-child cohort study in Spain with recruitment at first trimester of gestation (INMA Project, 2003–2008). Neuropsychological development was measured at 1 year of age using the Bayley Scales of Infant Development and at 4–5 years with the McCarthy Scales of Children's Abilities. Modeled tap water concentrations of trihalome…
Spontaneous release of endogenous 5-hydroxytryptamine and 5-hydroxyindoleacetic acid from the isolated vascularly perfused ileum of the guinea-pig
1987
The spontaneous release of 5-hydroxytryptamine and its metabolite 5-hydroxyindoleacetic acid from the enterochromaffin cells of the small intestine into the portal circulation was investigated in vitro using the vascularly perfused ileum of the guinea-pig. The release of 5-hydroxytryptamine decreased by 70% in a calcium-free medium and by 35% in the presence of tetrodotoxin. Inhibition of monoamine oxidase activity by pargyline (100 microM) had no effect on the spontaneous release of 5-hydroxytryptamine although it caused a 75% reduction in the outflow of 5-hydroxyindoleacetic acid. Imipramine (1 microM), an inhibitor of neuronal uptake of 5-hydroxytryptamine, reduced the 5-hydroxyindoleace…
l-[3H]lysine binding to rat retinal membrane: II. effect of kainic acid,d,l-?-aminoadipic acid, iodoacetic acid, and modification by dark-exposure
1986
The rat retina and the different brain regions contain membranes sites that bindl-lysine in the nanomolar range. These binding sites undergo changes in different experimental conditions, thus: I) intraocular injection of kainic acid induces a reduction of the density ofl-lysine binding sites, II)d,l-α-aminoadipic acid injected into the eye enhances both kinetic parameters (Bmax andKd) ofl-[3H]lysine binding sites, III) the intraperitoneal injection of iodoacetic acid decreases the sensitivity for its ligand binding sites, and IV) the exposure to darkness of the rats reducesl-[3H]lysine binding in the retina, thalamus, hypothalamus and superior colliculus, but not in the occipital cortex; su…
Influence of the amount of food ingested on mesolimbic dopaminergic system activity: a microdialysis study.
1996
Abstract The mesolimbic dopaminergic system (MDS) has been shown to be activated by ingestive behaviors, and it has been suggested that this activation may be related to the rewarding properties of foods. Because rats eat more when given a more palatable diet, this study was undertaken to determine the relationship between the amount of food ingested and DA release in the nucleus accumbens of freely moving rats. The extracellular levels of dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were measured by high-performance liquid chromatography with electrochemical detection on microdialysis samples from the nucleus accumbens. Each rat underwent three microdia…
Antinociceptive and anti-inflammatory activities of Acacia pennata wild (Mimosaceae)
2005
The butanolic fraction of dried leaves of Acacia pennata (Mimosaceae) was tested for analgesic and anti-inflammatory activities in animal models. It showed significant protective effects against chemical stimuli (acetic acid and formalin) in the mouse. It also produced a significant increase of the threshold of sensitivity to pressure-induced pain in the rats. The extract revealed an inhibitory effect in carrageenin-induced rat paw oedema in the late phase. The results suggested that a peripheral mechanism is involved in the analgesic, associated to anti-inflammatory effect (NSAIDs-like). Among the class of compounds characterized in this fraction, flavonoids may be mainly responsible for t…