Search results for "Prague"
showing 10 items of 652 documents
Nuclear fos domains in transcriptionally activated supraoptic nucleus neurons
1993
This study has analysed by light and electron microscopy immunolocalization the nuclear pattern of distribution of Fos-related proteins in supraotic neurons. Two experimental models of transcriptional activation have been used: sustained, global transcriptional activation, at relatively near physiological conditions, by six days of chronic intermittent salt loading; and superinduction of c-fos gene by this salt loading regime plus cycloheximide treatment for 4 h. In the first condition, the ultrastructural analysis showed a distribution of Fos-like immunoreactivity on the reticular network of dispersed chromatin that extends between the nucleolar surface and the nuclear envelope, whereas th…
Transcriptional analysis of rat photoreceptor cells reveals daily regulation of genes important for visual signaling and light damage susceptibility.
2013
Photoreceptor cells face the challenge of adjusting their function and, possibly, their susceptibility to light damage to the marked daily changes in ambient light intensity. To achieve a better understanding of photoreceptor adaptation at the transcriptional level, this study aimed to identify genes which are under daily regulation in photoreceptor cells using microarray analysis and quantitative PCR. Included in the gene set obtained were a number of genes which up until now have not been shown to be expressed in photoreceptor cells, such as Atf3 (activating transcription factor 3) and Pde8a (phosphodiesterase 8A), and others with a known impact on phototransduction and/or photoreceptor s…
Retinoic acid inhibits nitric oxide synthase-2 expression through the retinoic acid receptor-alpha.
2000
Retinoids are multipotent modulators of cellular functions and suppress cytokine-induced production of nitric oxide (NO) in several cell types. We have explored the mechanisms by which retinoic acid (RA) regulates NO production in rat aortic smooth muscle cells (VSMC), which express NOS2 in response to proinflammatory cytokines. RA inhibited interleukin-1beta (IL-1beta)-induced NOS2 mRNA expression and NO production. These effects were attenuated by the retinoic acid receptor (RAR) antagonist CD3106, indicating that they were mediated through retinoic acid receptors (RARs). The synthetic retinoid agonists CD336 (which specifically binds RARalpha) and CD367 (which binds all RARs) but not ago…
Propofol Impairs Neurogenesis and Neurologic Recovery and Increases Mortality Rate in Adult Rats After Traumatic Brain Injury*
2013
Objective: Limited data are available on the influence of sedation for critical care therapy with the widely used anesthetic propofol on recovery from acute traumatic brain injury. To establish the influence of propofol on endogenous neurogenesis and functional recovery after traumatic brain injury, rats were sedated with propofol either during or 2 hours after experimental traumatic brain injury. Design: Randomized controlled animal study. Setting: University research laboratory. Subjects: One hundred sixteen male Sprague Dawley rats. Interventions: Mechanical brain lesion by controlled cortical impact. Measurements and Main Results: This study investigated the dose-dependent influence of …
A critical role for TNFα in the selective attachment of mononuclear leukocytes to angiotensin-II-stimulated arterioles
2007
Abstract Angiotensin II (Ang-II) exerts inflammatory activity and is involved in different cardiovascular disorders. This study has evaluated the involvement of tumor necrosis factor alpha (TNFα) in the leukocyte accumulation elicited by Ang-II. Ang-II (1 nM intraperitoneally in rats) induced TNFα release at 1 hour followed by neutrophil and mononuclear cell recruitment. The administration of an antirat TNFα antiserum had no effect on Ang-IIinduced neutrophil accumulation but inhibited the infiltration of mononuclear cells and reduced CC chemokine content in the peritoneal exudate. Pretreatment with either an anti-TNFα or an anti-IL-4 antiserum decreased Ang-II-induced arteriolar mononuclea…
Perlecan-Induced Suppression of Smooth Muscle Cell Proliferation Is Mediated Through Increased Activity of the Tumor Suppressor PTEN
2004
We were interested in the elucidation of the interaction between the heparan sulfate proteoglycan, perlecan, and PTEN in the regulation of vascular smooth muscle cell (SMC) growth. We verified serum-stimulated DNA synthesis, and Akt and FAK phosphorylation were significantly reduced in SMCs overexpressing wild-type PTEN. Our previous studies showed perlecan is a potent inhibitor of serum-stimulated SMC growth. We report in the present study, compared with SMCs plated on fibronectin, serum-stimulated SMCs plated on perlecan exhibited increased PTEN activity, decreased FAK and Akt activities, and high levels of p27, consistent with SMC growth arrest. Adenoviral-mediated overexpression of cons…
Discrepancies Between Nitroglycerin and NO-Releasing Drugs on Mitochondrial Oxygen Consumption, Vasoactivity, and the Release of NO
2005
It has been generally acknowledged that the actions of glyceryl trinitrate (GTN) are a result of its bioconversion into NO. However, recent observations have thrown this idea into doubt, with many studies demonstrating that NO is present only when there are high concentrations of GTN. We have explored this discrepancy by developing a new approach that uses confocal microscopy to directly detect NO. Intracellular levels of NO in the rat aortic vascular wall have been compared with those present after incubation with 3 different NO donors (DETA-NO, 3-morpholinosydnonimine, and S -nitroso- N -acetylpenicillamine), endothelial activation with acetylcholine, or administration of GTN. We have al…
Acute normovolaemic anaemia prevents ethanol-induced gastric damage in rats through a blood flow related mechanism.
1994
The aim of the study was to assess whether changes in gastric mucosal blood flow induced by acute normovolaemic anaemia influence the susceptibility of the gastric mucosa to ethanol-induced damage, and the relationship of these changes with nitric oxide biosynthesis. Acute normovolaemic anaemia, promoted by exchanging 3 ml of blood by a plasma expander, induced a significant increase in gastric mucosal blood flow measured by hydrogen gas clearance, without changes in arterial blood pressure. After intragastric 60% ethanol administration, gastric blood flow was still significantly higher in anaemic than in control rats, and this was associated with a lower macroscopic and microscopic gastric…
Effects of Dehydroepiandrosterone Sulfate on Cellular Calcium Responsiveness and Vascular Contractility
1995
Abstract Dehydroepiandrosterone sulfate (DHEAS) is an endogenous steroid having a wide variety of biological effects, but its physiological role remains undefined. Since an age-related decline of DHEAS corresponds to the progressive onset of atherosclerosis, cardiovascular diseases, and overall mortality, we investigated a possible protective role of DHEAS in vascular disease by studying the effects of this hormone (10 −7 to 10 −5 mol/L) on cytosolic free calcium and contractility in different in vitro vascular tissue preparations. DHEAS produced a significant, dose-dependent relaxation of isolated helical strips of rat tail artery precontracted with KCl (60 mmol/L) (89.7±18.7%, P <.01)…
Comparative effects of the novel vasotocin analogue F-180 vs. vasopressin and terlipressin on systemic and splanchnic isolated vessels from portal hy…
2001
F-180 has been proposed as a new vasopressin analogue for the treatment of portal hypertension. This study investigates the contractile profile of F-180 compared to vasopressin and its analogue terlipressin on isolated systemic and splanchnic vessels from sham-operated and partial portal vein ligated (PPVL) rats. F-180 (10(-9)-10(-6) M), vasopressin (10(-11)-10(-8) M) and terlipressin (10(-9)-10(-4) M) induced contraction of the mesenteric vein, aorta, iliac, tail and mesenteric arteries. The order of potency in these vessels was vasopressin (pD2 approximately 9)F-180 (pD2 approximately 8)terlipressin (pD2 approximately 6). Significant (P0.01) differences between sham-operated and PPVL rats…