Search results for "rats"
showing 10 items of 3537 documents
Distribution of Met-enkephalyl-Arg-Gly-Leu in rat larynx: partial coexistence with vasoactive intestinal polypeptide, peptide histidine isoleucine an…
1990
Abstract Using light microscopic (LM) enzyme-immunohistochemistry on deparaffinized adjacent sections Met-enkephalyl-Arg-Gly-Leu (ME-RGL) immunoreactivity was found to partially coexist with immunoreactive neuropeptide Y (NPY), vasoactive intestinal polypeptide (VIP) and peptide histidine isoleucine (PHI) in intrinsic laryngeal neurons of the rat. Further ME-RGL-immunoreactive (ir) fibres were found around glands in the subepithelium, in connective tissue of striated muscle and in the perichondrium, as well as around arterial and venous blood vessels. They frequently contacted mast cells and macrophages. The presence of ME-RGL indicates pro-enkephalin-related origin of this novel laryngeal …
Characteristics of histamine tachyphylaxis in rat uterine smooth muscle.
2002
Objective and design: To study both the desensitisation induced by short-term exposure to histamine and the mechanism responsible in the isolated rat uterus.¶Material: Precontracted isolated uterus (37 mM KCl) from oestrogenised Wistar rats were used.¶Treatment: Repetitive responses to histamine (10–6, 10–5, 10–4, 10–3 M), dimaprit and clonidine (10–4 M) were tested at 15, 30, 45 and 105 min., with their modifications by (5 mg/ kg, 24 h before sacrifice) reserpine, 10–7 M propranolol, 10–8 M atropine, and 10–6 M indomethacin. Dose-response curves for adrenaline were carried out as standard protocol.¶Methods: In vitro techniques (de Jalon's solution, 31°C, carbogen, isotonic registration, re…
Inhibition of intracellular Ca2+ release by a Rho-kinase inhibitor for the treatment of ischemic damage in primary cultured rat hippocampal neurons.
2008
The effects of hydroxy fasudil, a specific Rho-kinase inhibitor, on behavior and brain neuronal activity in animal studies have been described previously. However, whether a Rho-kinase inhibitor can directly protect neurons against ischemic damage and the molecular mechanisms underlying these effects are poorly understood. The present work was designed to investigate the effect of hydroxy fasudil against oxygen-glucose deprivation (OGD) induced acute neuronal injury and the underlying mechanisms in vitro. Pretreatment with hydroxy fasudil at 5 and 10 microM could concentration-dependently improve cell viability and decrease Lactate dehydrogenase (LDH) level in extracellular solution of neur…
The impact of alpha1-adrenoceptors up-regulation accompanied by the impairment of beta-adrenergic vasodilatation in hypertension
2008
9 pages, 7 figures, 3 tables.-- PMID: 19060223 [PubMed]
Prooxidative toxicity and selenoprotein suppression by cerivastatin in muscle cells
2012
Statins are the most widely used drugs for the treatment of hypercholesterolemia. In spite of their overall favorable safety profile, they do possess serious myotoxic potential, whose molecular origin has remained equivocal. Here, we demonstrate in cultivated myoblasts and skeletal muscle cells that cerivastatin at nanomolar concentrations interferes with selenoprotein synthesis and evokes a heightened vulnerability of the cells toward oxidative stressors. A correspondingly increased vulnerability was found with atorvastatin, albeit at higher concentrations than with cerivastatin. In selenium-saturated cells, cerivastatin caused a largely indiscriminate suppression of selenoprotein biosynth…
Adrenergic Stimulation of Cyclic GMP Formation Requires NO-Dependent Activation of Cytosolic Guanylate Cyclase in Rat Pinealocytes
1993
Cyclic GMP (cGMP) formation in rat pinealocytes is regulated through a synergistic dual receptor mechanism involving beta- and alpha 1-adrenergic receptors. The effects of NG-monomethyl-L-arginine (NMMA), which inhibits nitric oxide (NO) synthase and NO-mediated activation of cytosolic guanylate cyclase, and methylene blue (MB), which inhibits cytosolic guanylate cyclase, were investigated in an attempt to understand the role of NO in adrenergic cGMP formation. Both NMMA and MB inhibited beta-adrenergic stimulation of cGMP formation as well as alpha 1-adrenergic potentiation of beta-adrenergic stimulation of cGMP formation, whereas they had no effect in unstimulated pinealocytes. The inhibi…
Release of [3H]acetylcholine from the isolated rat or guinea-pig trachea evoked by preganglionic nerve stimulation; a comparison with transmural stim…
1991
Basal and stimulated outflow of radioactive acetylcholine, phosphorylcholine and choline from rat and guinea-pig isolated tracheae were measured by reverse phase HPLC followed by liquid-scintillation-spectrometry. Tracheae were stimulated either by an electrical field (transmural stimulation) or by a local stimulation of the innervating parasympathetic nerves (preganglionic stimulation). Epithelium was removed in most experiments, as the epithelium inhibits acetylcholine release. The basal tritium efflux (1,600 dpm/3min) from rat isolated tracheae incubated with [3H]choline consisted of 56% [3H]phosphorylcholine and 38% [3H]choline. Preganglionic stimulation (15 Hz, 1,200 pulses) caused a 2…
Hypoosmolar conditions reduce extracellular volume fraction and enhance epileptiform activity in the CA3 region of the immature rat hippocampus
2006
The osmolarity of the extracellular space (ECS) compartment is an important factor determining the excitability of neuronal tissue. In the adult hippocampus an important role of osmolarity and ECS diffusion parameters on the susceptibility to epileptic events is well established, but the influence of hypo- and hyperosmolar conditions on the immature hippocampus remains elusive. To investigate the influence of osmolarity on epileptiform activity, extracellular field potentials were recorded in the CA3 region of hippocampal slices of immature (postnatal days 4-7) Wistar rats. The ECS diffusion parameters were determined by the real-time tetramethylammonium (TMA+) iontophoretic method with ion…
Lysosomal trafficking in rat cardiac myocytes.
1990
By immunolabeling of cryosections, we have characterized in rat cardiac myocytes the cation-independent mannose-6-phosphate receptor (MPR), a lysosomal membrane glycoprotein, lgp120, and a lysosomal enzyme, MEP (homologous to cathepsin L). Most of the MPR label was located in large membrane-filled structures (MPR structures) in large clusters of mitochondria adjacent to but distinct from the Golgi complex. Lpg120 and MEP showed typical lysosomal localization throughout the cell, often associated with regions that appeared to contain autophagosome-like structures. In addition, MEP and lgp120 co-localized within MPR structures. MEP and MPR were localized inside the lumen of MPR structures. M…
Contracting striated muscle fibres differentiated from primary rat pituitary cultures.
1982
Whole pituitaries or adenohypophyses alone of adult female Wistar/ Furth rats were dissociated into single cells by means of two different enzymic disintegration methods. The single-cell suspension was then seeded out and cultured for up to 8 months in tissue culture dishes with untreated and polylysine coated surfaces. The cells were cultured in different sera (horse serum, newborn-calf serum, fetal-calf serum, mixtures of horse and newborn-calf serum, and isogenic rat serum) and also in a serum-free, hormone-supplemented medium. When the cells were cultured in medium containing horse serum (15 %) plus fetal-calf serum (3%) on polylysine-treated surfaces, cell fusion and the development of…