Search results for "Wistar"
showing 10 items of 1094 documents
Age-related increase in xanthine oxidase activity in human plasma and rat tissues.
2007
This study assessed the role of xanthine oxidase in vascular ageing. A positive correlation between xanthine oxidase activity and age was found in human plasma. Similar results were found in rat plasma. Xanthine oxidase expression and activity in homogenates from the aortic wall were significantly higher in samples from old rats than in their young counterparts (p<0.01). In rat skeletal muscle homogenates both xanthine oxidase expression and activity showed a similar age-related profile. Superoxide production by xanthine oxidase in aortic rings was higher in aged rats. Uric acid, the final product of xanthine oxidase has been proposed as a risk factor for coronary heart disease and an indep…
Changes in metabolism of inorganic polyphosphate in rat tissues and human cells during development and apoptosis
1997
Age-dependent studies show that the amount of inorganic polyphosphate in rat brain strongly increases after birth. Maximal levels were found in 12-months old animals. Thereafter, the concentration of total polyphosphate decreases to about 50%. This decrease in the concentration of total polyphosphate is due to a decrease in the amount of insoluble, long-chain polyphosphates. The amount of soluble, long-chain polyphosphates does not change significantly in the course of ageing. In rat embryos and newborns, mainly soluble polyphosphates could be detected. In rat liver, the age-dependent changes are less pronounced. The changes in polyphosphate level are accompanied by changes in exopolyphosph…
Pharmacological intervention in age-associated brain disorders by Flupirtine: Alzheimer’s and Prion diseases
1998
Alzheimer's disease, a major form of dementia in the elderly has become an increasingly important health problem in developed countries. In vitro studies on primary neurons demonstrate that Flupirtine (Katadolon) at a concentration of 1 microg/ml, significantly reduces the neurotoxic (apoptotic) effect displayed by A beta25-35, a segment of the amyloid beta-protein precursor the etiologic agent of Alzheimer's disease. Flupirtine, which has been in clinical use since 10 years ago, prevents the toxic effect of PrP, the presumed etiologic agent of the Creutzfeldt-Jakob disease as well as the excitatory amino acid glutamate on cortical neurons. Flupirtine displays a bimodal activity. Its strong…
Age-Related Changes of Liver Antioxidant Enzymes and 8-Hydroxy-2-Deoxyguanosine During FetalNeonate Transition and Early Rat Development
2000
We have studied the pro-antioxidant status of the rat liver on the last day of gestation and at 1, 15, and 30 days of extrauterine life. Representative variables, such as activities of superoxide dismutase (SOD), catalase, and glutathione peroxidase and concentrations of reduced glutathione and 8-hydroxy-2'-deoxyguanosine, were determined in liver to assess the degree of birth-associated oxidative stress during the fetal-neonatal transition and early development of the rat. Percentages by which liver Cu/ZnSOD activity increased over the basal value of the fetal liver were 54%, 95%, and 127% at neonatal days 1, 15, and 30, respectively. There was a lack of induction in the development profil…
Age-associated oxidative damage leads to absence of γ-cystathionase in over 50% of rat lenses: Relevance in cataractogenesis
2004
Oxidative damage to lens proteins and glutathione depletion play a major role in the development of senile cataract. We previously found that a deficiency in gamma-cystathionase activity may be responsible for glutathione depletion in old lenses. The aims of this study were: (1) to investigate the mechanism that causes the age-related deficiency in gamma-cystathionase activity in the eye lens, and (2) to determine the role of gamma-cystathionase deficiency in cataractogenesis. Two populations of old rats were found, one (56%) whose lenses lacked gamma-cystathionase activity and the rest that exhibited detectable enzyme activity. gamma-Cystathionase protein was absent in lenses from old rats…
Cannabinoid and nitric oxide signaling interplay in the modulation of hippocampal hyperexcitability: study on electrophysiological and behavioral mod…
2015
A growing bulk of evidence suggests that cannabinoid system plays a pivotal role in the control of hyperexcitability phenomena. Notwithstanding, the anticonvulsant action of cannabinoids has not been fully addressed, in particular the involvement of potential cellular neuromodulators, for instance nitric oxide. In the current study, we focused on two distinct rat models of temporal lobe epilepsy, the Maximal Dentate Activation and the pilocarpine-induced acute seizures, providing both electrophysiological and behavioral data on cannabinoid and nitrergic system interplay. We evaluated the antiepileptic effects of WIN 55,212-2, (R)-(+)-[2,3-dihydro-5-methyl-3-(4- morpholinylmethyl) pyrrolo[1,…
Evidences of cannabinoids-induced modulation of paroxysmal events in an experimental model of partial epilepsy in the rat.
2009
The anticonvulsant effect of cannabinoids (CB) has been shown to be mediated by the activation of the CB(1) receptor. This study evaluates the anticonvulsant activity of (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl) pyrrolo[1,2,3-de]-1,4-benzoxazin-6-Yl]-1-naphthalenylmethanone (WIN55,212-2, CB agonist) alone or preceded by the administration of N-(piperidin-1-yl)-5-(4-iodophenyl)-1-(2,4-dichlorophenyl)-4-methyl-1H-pyrazole-3-carboxamide (AM251, selective CB(1) antagonist) in an experimental in vivo model of complex partial seizures (maximal dentate gyrus activation - MDA) in the rat. WIN55,212-2 (21mgkg(-1)) exerted an anticonvulsant effect, significantly reduced by the pre-treatme…
Systemic administration of D-penicillamine prevents the locomotor activation after intra-VTA ethanol administration in rats.
2010
Although recently published studies seem to confirm the important role displayed by acetaldehyde (ACH), the main metabolite of ethanol, in the behavioral effects of ethanol, the origin of ACH is still a matter of debate. While some authors confer more importance to the central (brain metabolism) origin of ACH, others indicate that the hepatic origin could be more relevant. In this study we have addressed this topic using an experimental approach that combines local microinjections of ethanol into the ventral tegmental area (VTA) (which guarantees the brain origin of the ACH) to induce motor activation in rats together with systemic administration (i.p.) of several doses (0, 12.5, 25 and 50 …
Role of CB2 receptors and cGMP pathway on the cannabinoid-dependent antiepileptic effects in an in vivo model of partial epilepsy.
2014
This study aimed at providing an insight on the possible role of cannabi-noid (CB) type 2 receptors (CB2R) and cGMP pathway in the antiepileptic activity ofWIN 55,212-2, (R)-(+)-[2,3-dihydro-5-methyl-3-(4-morpholinylmethyl) pyrrolo[1,2,3-de]-1,4-benzoxazin-6-Yl]-1-naphthalenylmethanone, a non-selective CB agonist, in the maximal dentate activation (MDA) model of partial epilepsy in adult male rats. We evaluated the activity of a CB2 antagonist/inverse agonist AM630, [6-iodo-2-methyl-1-[2-(4-morpholinyl)ethyl]-1H-indol-3-yl](4-methoxyphenyl)methanone or 6-iodopravadoline, alone or in co-administration with WIN 55,212-2. Also, in the MDA model it was investigated the co-treatment of WIN55,212…
Histaprodifens: synthesis, pharmacological in vitro evaluation, and molecular modeling of a new class of highly active and selective histamine H(1)-r…
2000
A new class of histamine analogues characterized by a 3, 3-diphenylpropyl substituent at the 2-position of the imidazole nucleus has been prepared outgoing from 4,4-diphenylbutyronitrile (4b) via cyclization of the corresponding methyl imidate 5b with 2-oxo-4-phthalimido-1-butyl acetate or 2-oxo-1,4-butandiol in liquid ammonia, followed by standard reactions. The title compounds displayed partial agonism on contractile H(1) receptors of the guinea-pig ileum and endothelium-denuded aorta, respectively, except 10 (histaprodifen; 2-[2-(3, 3-diphenylpropyl)-1H-imidazol-4-yl]ethanamine) which was a full agonist in the ileum assay. While 10 was equipotent with histamine (1), methylhistaprodifen (…