Search results for "Wistar"
showing 10 items of 1094 documents
Hypothalamic Astroglial Connexins are Required for Brain Glucose Sensing-Induced Insulin Secretion
2014
Supplementary Information accompanies the paper on the Journal of Cerebral Blood Flow & Metabolism website; Hypothalamic glucose detection participates in maintaining glycemic balance, food intake, and thermogenesis. Although hypothalamic neurons are the executive cells involved in these responses, there is increasing evidence that astrocytes participate in glucose sensing (GS); however, it is unknown whether astroglial networking is required for glucose sensitivity. Astroglial connexins 30 and 43 (Cx30 and Cx43) form hexameric channels, which are apposed in gap junctions, allowing for the intercellular transfer of small molecules such as glucose throughout the astroglial networks. Here, we…
Immunocytochemistry of M-cadherin in mature and regenerating rat muscle
1994
Background: Cadherins are transmembrane proteins mediating calcium-dependent cell–cell adhesion in a cell type-specific manner by means of homophilic binding. M(muscle)-cadherin is a recently detected member of the cadherin family. Methods: We have investigated the localization of M-cadherin innormal and aneurally regenerating skeletal muscle of rat by means of pre-embedding immunocytochemistry. The antibody was directed against the extra-cellular domain of M-cadherin. Results: Myoblasts and myotubes in regenerating muscles tended to be arranged in clusters enclosed by a common basal lamina. Satellite cells of mature muscle fibers were attached to the underlying fiber without separating bas…
Echinostoma caproni: identification of enolase in excretory/secretory products, molecular cloning, and functional expression.
2007
In order to investigate molecules that could be involved in host-trematode relationships, we have analysed the excretory/secretory products (ESP) of Echinostoma caproni following a proteomic approach. Actin, Gluthathione S-transferase (GST) and enolase have been identified in the ESP. Enolase, observed to be one of the most abundant proteins, was further characterized. The molecular cloning and in vitro expression in Escherichia coli of E. caproni enolase allowed us to determine that the protein contains 431 amino acids and a theoretical MW of 46272 Da. E. caproni enolase shows high homology to other trematode enolases. The recombinant protein binds specifically to human plasminogen in vitr…
Complement C1q is dramatically up-regulated in brain microglia in response to transient global cerebral ischemia.
2000
Abstract Recent evidence suggests that the pathophysiology of neurodegenerative and inflammatory neurological diseases has a neuroimmunological component involving complement, an innate humoral immune defense system. The present study demonstrates the effects of experimentally induced global ischemia on the biosynthesis of C1q, the recognition subcomponent of the classical complement activation pathway, in the CNS. Using semiquantitative in situ hybridization, immunohistochemistry, and confocal laser scanning microscopy, a dramatic and widespread increase of C1q biosynthesis in rat brain microglia (but not in astrocytes or neurons) within 24 h after the ischemic insult was observed. A marke…
Th17 responses in Echinostoma caproni infections in hosts of high and low compatibility.
2011
In order to investigate the factors determining the expulsion of intestinal helminths, we have analyzed the in vivo expression of IL-17, TGF-β and IL-23 in several tissues of two host species displaying different compatibility with Echinostoma caproni (Trematoda). We did not observe upregulation of these cytokines in any of the tissues of the high compatible host (mice). In contrast, the responses in the host of low compatibility (rats) with the parasite were markedly different. Significant increases in the expression of IL-17 and TGF-β were observed in the Peyer's patches and the intestine from the 2 to 8 weeks post-infection. The expression of IL-23 was upregulated from 2 to 4 weeks post-…
Investigating drug absorption from the colon: Single-pass vs. Doluisio approaches to in-situ rat large-intestinal perfusion
2017
Traditionally, the colon is considered a secondary intestinal segment in the drug absorption process. However, in many cases the role of colonic drug permeability cannot be overlooked. The purpose of this research was to compare colon permeability data obtained using two different rat perfusion methods the single-pass intestinal perfusion (SPIP) approach and the closed-loop (Doluisio) perfusion model. A list of 14 structurally diverse model drugs was constructed, and their rat colon permeability was studied using the two methods. The two sets of results were compared to each other, and were evaluated vs. in-vitro, ex-vivo, and in-vivo literature values. The SPIP and the Doluisio results exh…
Biophysical Models as an Approach To Study Passive Absorption in Drug Development: 6-Fluoroquinolones
1995
A preliminary study attempting to assess and explain the intestinal absorption of a series of antibacterial 7-piperazinyl-6-fluoroquinolones is presented. The synthesis, n-octanol partition coefficients, intrinsic rat gut in situ absorption rate constants, and in vitro antibacterial activity data found for these homologous compounds are described. A fluorimetric, reverse-phase HPLC method was performed for the quantification of the quinolones in absorption and partition samples. Equations based on two classic biophysical absorption models are given for predicting the intrinsic absorption features of the series according to the partition data or merely single structural parameters. In situ a…
Segmental-dependent permeability throughout the small intestine following oral drug administration: Single-pass vs. Doluisio approach to in-situ rat …
2016
Abstract Intestinal drug permeability is position dependent and pertains to a specific point along the intestinal membrane, and the resulted segmental-dependent permeability phenomenon has been recognized as a critical factor in the overall absorption of drug following oral administration. The aim of this research was to compare segmental-dependent permeability data obtained from two different rat intestinal perfusion approaches: the single-pass intestinal perfusion (SPIP) model and the closed-loop (Doluisio) rat perfusion method. The rat intestinal permeability of 12 model drugs with different permeability characteristics (low, moderate, and high, as well as passively and actively absorbed…
The discharge of subthalamic neurons is modulated by inhibiting the nitric oxide synthase in the rat.
2005
The effects induced on the discharge of subthalamic spontaneously active neurons by inhibiting the enzyme nitric oxide synthase was studied in two groups of urethane-anesthetized rats. In the first group of animals (n = 10), the activity of subthalamic single units was recorded before and after the systemic administration of 7-nitro-indazole (7-NI, 50 mg/kg i.p.), a selective inhibitor of neuronal nitric oxide synthase. In the second group of rats (n = 15), Nomega-nitro-L-arginine methyl ester (L-NAME), another inhibitor of nitric oxide synthase, was iontophoretically administered while performing single unit extracellular recordings. The activity of most tested spontaneously discharging ne…
Involvement of Dopamine D2 Receptors in Addictive-Like Behaviour for Acetaldehyde
2014
Acetaldehyde, the first metabolite of ethanol, is active in the central nervous system, where it exerts motivational properties. Acetaldehyde is able to induce drinking behaviour in operant-conflict paradigms that resemble the core features of the addictive phenotype: drug-intake acquisition and maintenance, drug-seeking, relapse and drug use despite negative consequences. Since acetaldehyde directly stimulates dopamine neuronal firing in the mesolimbic system, the aim of this study was the investigation of dopamine D2-receptors' role in the onset of the operant drinking behaviour for acetaldehyde in different functional stages, by the administration of two different D2-receptor agonists, q…