Search results for "wistar"
showing 10 items of 1094 documents
The effects of insulin on transport and metabolism of glucose in skeletal muscle from hyperthyroid and hypothyroid rats.
1997
The effects of insulin on the rates of glucose disposal were studied in soleus muscles isolated from hyper- or hypothyroid rats. Treatment with triiodothyronine for 5 or 10 days decreased the sensitivity of glycogen synthesis but increased the sensitivity of lactate formation to insulin. The sensitivity of 3-O methylglucose to insulin was increased only after 10 days of treatment and was accompanied by an increase in the sensitivity of 2-deoxyglucose phosphorylation; however, 2-deoxyglucose and glucose 6-phosphate in response to insulin remained unaltered. In hypothyroidism, insulin-stimulated rates of 3-O-methylglucose transport and 2-deoxyglucose phosphorylation were decreased; however, a…
Cecal Resection with Bipolar Sealing Devices in a Rat Model
2018
Background: Bipolar sealing devices are routinely used to seal blood vessels. The aim of the study is to evaluate the feasibility and safety of colonic sealing with the use of the bipolar energy devices in rats as model for experimental appendectomy. Methods: Seventy-five male Wistar rats underwent a cecal resection with four different bipolar sealing devices or a linear stapler. The harvesting procedure was performed immediately or at postoperative day (POD) 7. The sealing front bursting pressure (BP) was measured in both groups. At POD7, the resection line was clinically examined and the hydroxyproline (HDP) levels were determined. Hematoxylin and Eosin (H&E) staining was used for histopa…
Microstructure of rat behavioral response to anxiety in hole-board
2010
Aim of present research was to assess, by means of descriptive and multivariate approaches, in Wistar rats tested in hole-board apparatus, whether a microstructure of hole exploratory behavior may be identified in the behavioral response to anxiety. Two groups of 15 subjects were tested: one received 1 ml of saline IP and one was IP injected with diazepam at 0.5 mg/kg dissolved in 1 ml of saline. Following saline, six not yet reported hole-exploratory components were identified: active-dip, static-dip, rapid-dip, circular-sniff, point-sniff and central-sniff. Diazepam provoked significant changes of their per cent distribution. Results of multivariate analyses revealed a complex microstruct…
Nanoaggregates Based on New Poly-Hydroxyethyl-Aspartamide Copolymers for Oral Insulin Absorption
2013
The aim of this work was to produce copolymers with an appropriate hydrophilic/hydrophobic balance able to form nanoaggregates with protein molecules and to be used as ideal materials in the field of oral peptide/protein delivery. New anionic polymers obtained by the conjugation of carboxy-bearing ligands, like succinic anhydride and/or cysteine, to hydrophobized α,β-poly(N-2-hydroxyethyl)-dl-aspartamide (PHEA) copolymers have been synthesized and characterized. Starting copolymer was synthesized by the partial derivatization of hydroxyl groups on the PHEA backbone with butylamine (C4) (obtaining the PHEA-C4 copolymer, bearing a butyl moiety). The consecutive reaction of PHEA-C4 with succin…
In vitro and in vivo porphyrin accumulation by C6 glioma cells after exposure to 5-aminolevulinic acid
1998
Several malignant tissues synthesize endogenous porphyrins after exposure to 5-aminolevulinic acid (5-ALA). The present experiments have been designed to elucidate whether the C6 glioma cell, a model cell for human malignant glioma, similarly synthesizes porphyrins when exposed to 5-ALA, and whether specific synthesis occurs when C6 cells are inoculated into rat brains to form a tumor. In this situation the blood-brain barrier may interfere with 5-ALA availability, and spreading of porphyrins with edema outside the tumor may occur. Flow cytometry is used to determine the course of cell volume and porphyrin fluorescence intensities in cultured C6 cells which are incubated in 1 mM 5-ALA. For …
N-valproyl-L-tryptophan for CNS-targeting: synthesis, characterization and efficacy in vitro studies of a new potential antiepileptic drug.
2010
A new aminoacidic derivative of valproic acid (VPA) has been synthesized and characterized by analytical and spectral data. The rationale for the preparation of such potential antiepileptic agent is based on the observation that chemical combination of the anticonvulsant pharmacophore, VPA with essential aminoacids could afford more effective and less toxic actives. The synthesis, characterization, physico-chemical parameters functional for crossing Blood Brain Barrier of N-valproyl-L-tryptophan (4) are reported. The Log D pH7.4 (0.3) indicates that (4) is adequate to cross biological membranes. Its chemical and enzymatic stability were assessed. The experiments indicate high stability of c…
Echinostoma caproni (Trematoda): differential in vivo cytokine responses in high and low compatible hosts.
2011
In order to investigate the factors determining the expulsion of intestinal trematodes, we have analyzed the in vivo cytokine responses at several levels and the local responses against Echinostoma caproni (Trematoda) in two host species displaying different compatibility with the parasite. The response of the high compatible host (mice) is characterized by a mixed Th1/Th2 phenotype in the spleen, Peyer's patches and mesenteric lymph nodes. At the intestine, a marked Th1 response with a marked increase of IFN-γ together with elevated number of mucosal neutrophils and expression of induced nitric oxide synthase were observed. The responses in the host of low compatibility (rats) with the par…
Cholecystokinin-8 sulfate modulates the anticonvulsant efficacy of vigabatrin in an experimental model of partial complex epilepsy in the rat.
2009
Summary Purpose: We evaluated the possible additive effect induced by the administration of the anticonvulsant vigabatrin (VGB) and cholecystokinin-8 sulfate (CCK-8S) on an experimental model of partial complex seizures (maximal dentate gyrus activation, MDA). Moreover, the functional involvement of γ-aminobutyric acid (GABA) neurotransmission was tested by iontophoretically administering bicuculline (GABA receptor antagonist) in the dentate gyrus. Methods: Urethane anesthetized rats were pretreated with VGB (50, 100 or 200 mg/kg, i.p.) or CCK-8S (8 nmol/kg, i.p.) alone or coadministered with VGB (50 mg/kg, i.p.). Dentate gyrus epileptic activity was obtained through the repetitive electr…
Post-initiation modulating effects of allyl sulfides in rat hepatocarcinogenesis
2004
Effects of administration of diallyl sulfide (DAS) and diallyl disulfide (DADS) on the promotion stage of hepatocarcinogenesis were investigated in rats using the Ito model. They were compared with those of phenobarbital (PB), a well-known liver promoter in rats. Initiation was induced by a single dose of N-nitrosodiethylamine (NDEA) and 3 weeks later, a partial hepatectomy was conducted. Two weeks after the NDEA injection, rats received either 0.05% allyl sulfides, PB or both in their diet for 8 weeks. Feeding with DAS increased the number of liver preneoplastic foci by 63% with respect to the untreated group. However, rats fed DAS showed a lower foci development than rats fed PB. The DADS…
Prevention of Rat Intestinal Injury with a Drug Combination of Melatonin and Misoprostol
2020
A healthy intestinal barrier prevents uptake of allergens and toxins, whereas intestinal permeability increases following chemotherapy and in many gastrointestinal and systemic diseases and disorders. Currently, there are no approved drugs that target and repair the intestinal epithelial barrier while there is a medical need for such treatment in gastrointestinal and related conditions. The objective of this single-pass intestinal perfusion study in rats was to investigate the preventive cytoprotective effect of three mucosal protective drugs&mdash