Search results for "Wistar"
showing 10 items of 1094 documents
Nitrergic and purinergic interplay in inhibitory transmission in rat gastric fundus.
2007
Summary 1 This study was undertaken to analyse the involvement of ATP in non-adrenergic non- cholinergic (NANC) relaxation and possible interplay between nitrergic and purinergic systems in rat gastric fundus. 2 Experiments were performed in vitro on strips of longitudinal muscle from rat gastric fundus, recording the mechanical activity as changes in isometric force. In addition, NO release induced by different experimental conditions was assayed. 3 Under NANC conditions in serotonin-precontracted strips, electrical field stimulation (EFS) elicited a tetrodotoxin (TTX)-sensitive relaxation accompanied by nitric oxide (NO) release. This effect was antagonized by pretreatment with the NO …
Nitric oxide is involved in non-adrenergic, non-cholinergic inhibitory neurotransmission in rat duodenum
1995
1. In rat duodenum, electrical field stimulation (EFS) induced a relaxation due to activation of non-adrenergic, non-cholinergic (NANC) inhibitory intramural neurones. 2. Nitric oxide synthase (NOS) inhibitors, N omega-nitro-L-arginine (L-NNA) and N omega-nitro-L-arginine methyl ester (L-NAME), caused a dose-dependent reduction in amplitude of the NANC relaxation. Responses to low frequencies of stimulation were more sensitive to NOS inhibitors than those to high frequencies. 3. Effects induced by NOS inhibitors were stereospecific since D-NNA and D-NAME did not affect NANC relaxation. L-arginine, but not D-arginine, partially prevented the effects induced by NOS inhibitors on NANC relaxati…
Nitric oxide as neuromodulator of sympathetic transmission in rat vas deferens.
1998
Summary Electrical field stimulation (EFS) of muscle strips in vitro elicited a tetrodotoxin (TTX)-sensitive biphasic contractile response consisting of a phasic component followed by a tonic one. The amplitude of both components of the response was impaired by Nω-nitro-L-arginine and potentiated by sodium nitroprusside. Cystamine caused a reduction in amplitude of both phasic and tonic componets of the response to EFS. Neither Nω-nitro-L-arginine, sodium nitroprusside, nor cystamine induced changes in the resting muscle tone, or in the contractile response to exogenous agonists ATP and noradrenaline (NA). The nitric oxide scavenger, 2-phenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide, i…
Liver subcellular fractions from rats treated by organosulfur compounds from Allium modulate mutagen activation
2000
The effects of in vivo administration of naturally occurring organosulfur compounds (OSCs) from Allium species were studied on the activation of several mutagens. Male SPF Wistar rats were given p.o. one of either diallyl sulfide (DAS), diallyl disulfide (DADS), dipropyl sulfide (DPS) or dipropyl disulfide (DPDS) during 4 consecutive days and the ability of hepatic S9 and microsomes from treated rats to activate benzo[a]pyrene (BaP), cyclophosphamide (CP), dimethylnitrosamine (DMN), N-nitrosopiperidine (N-PiP) and 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) was determined in the Ames test. Administration of DAS, DPS and DPDS resulted in a significant increase of the activation of…
Oxidative and nitrosative stress in acute pancreatitis. Modulation by pentoxifylline and oxypurinol
2011
Item does not contain fulltext Reactive oxygen species are considered mediators of the inflammatory response and tissue damage in acute pancreatitis. We previously found that the combined treatment with oxypurinol - as inhibitor of xanthine oxidase- and pentoxifylline - as inhibitor of TNF-alpha production-restrained local and systemic inflammatory response and decreased mortality in experimental acute pancreatitis. Our aims were (1) to determine the time-course of glutathione depletion and oxidation in necrotizing pancreatitis in rats and its modulation by oxypurinol and pentoxifylline; (2) to determine whether TNF-alpha is responsible for glutathione depletion in acute pancreatitis; and (…
The use of the Emotional-Object Recognition as an assay to assess learning and memory associated to an aversive stimulus in rodents
2016
Abstract Background Emotionally salient experiences induce the formation of explicit memory traces, besides eliciting automatic or implicit emotional memory in rodents. This study aims at investigating the implementation of a novel task for studying the formation of limbic memory engrams as a result of the acquisition- and retrieval- of fear-conditioning – biased declarative memory traces, measured by animal discrimination of an “emotional-object”. Moreover, by using this new method we investigated the potential interactions between stimulation of cannabinoid transmission and integration of emotional information and cognitive functioning. New method The Emotional-Object Recognition task is …
GABAergic basal forebrain afferents innervate selectively GABAergic targets in the main olfactory bulb
2010
In this work we have analyzed the targets of the GABAergic afferents to the main olfactory bulb originating in the basal forebrain of the rat. We combined anterograde tracing of 10 kD biotinylated dextran amine (BDA) injected in the region of the horizontal limb of the diagonal band of Broca that projects to the main olfactory bulb, with immunocytochemical detection of GABA under electron microscopy or vesicular GABA transporter (vGABAt) under confocal fluorescent microscopy. GABAergic afferents were identified as double labeled BDA-GABA boutons. Their targets were identified by their ultrastructure and GABA content. We found that GABAergic afferents from the basal forebrain were distribute…
Parvalbumin-containing interneurons do not innervate granule cells in the olfactory bulb
2001
Combining pre-embedding parvalbumin immunostaining and post-embedding immunogold detection of GABA in the olfactory bulb, we investigated whether the parvalbumin-containing GABAergic interneurons of the external plexiform layer exclusively innervate principal cells, or whether they also establish inhibitory synapses upon GABAergic local neurons such as granule cells. Our results demonstrate that the parvalbumin-containing cells do not contact GABAergic interneurons in the neuropil of the external plexiform layer. On the contrary, their postsynaptic elements were always non-GABAergic principal cells. Although classically it has been accepted that the interneurons of the external plexiform la…
A Scanning Technique to Measure Regional Cerebral Blood Flow and Oxyhemoglobin Level
2001
OBJECTIVE: The application of a laser scanning technique to measure regional cerebral blood flow (CBF) and tissue hemoglobin oxygenation (HbO 2 ) using the rat closed cranial window preparation is described. METHODS: Twenty-nine male Wistar rats were used to consecutively measure local CBF by laser Doppler flowmetry and tissue HbO 2 by a microspectrophotometric method at multiple corresponding cortical locations. The scanning technique used a computer-controlled micromanipulator. Data from three experimental models are presented: the whisker stimulation model, the ischemia-reperfusion model, and the sinus-vein thrombosis model. Sequential changes in local CBF and HbO 2 data before, during, …
Oxidative metabolism in a rat hepatoma (N13) and isolated rat hepatocytes: A flow cytometric comparative study
1996
Recently, we have developed a new and fast kinetic method for assessing mitochondrial membrane potential by flow cytometry, based on the quantitation of the initial rate of rhodamine 123 (Rh123) uptake by living cells. This test has proved suitable to detect metabolic and toxic effects on mitochondria. To characterize energy metabolism in a rat hepatoma cell line (N13), we applied this method to assess several metabolic pathways that eventually generate mitochondrial membrane potential. Using this approach, we found that N13 hepatoma cells retain an oxidative capacity comparable with that observed in isolated hepatocytes under the same conditions. These results show that this cell line may …