Search results for "Prague"
showing 10 items of 652 documents
Trans- but not cis-resveratrol impairs angiotensin-II-mediated vascular inflammation through inhibition of NF-κB activation and peroxisome proliferat…
2010
Abstract Angiotensin II (Ang-II) displays inflammatory activity and is implicated in several cardiovascular disorders. This study evaluates the effect of cis- and trans (t)-resveratrol (RESV) in two in vivo models of vascular inflammation and identifies the cardioprotective mechanisms that underlie them. In vivo, Ang-II–induced arteriolar leukocyte adhesion was inhibited by 71% by t-RESV (2.1 mg/kg, i.v.), but was not affected by cis-RESV. Because estrogens influence the rennin-angiotensin system, chronic treatment with t-RESV (15 mg/kg/day, orally) inhibited ovariectomy-induced arteriolar leukocyte adhesion by 81%, partly through a reduction of cell adhesion molecule (CAM) expression and c…
Angiotensin II Induces Neutrophil Accumulation In Vivo Through Generation and Release of CXC Chemokines
2004
Background—Angiotensin II (Ang II) is implicated in the development of cardiac ischemic disorders in which prominent neutrophil accumulation occurs. Ang II can be generated intravascularly by the renin-angiotensin system or extravascularly by mast cell chymase. In this study, we characterized the ability of Ang II to induce neutrophil accumulation.Methods and Results—Intraperitoneal administration of Ang II (1 nmol/L) induced significant neutrophil recruitment within 4 hours (13.3±2.3×106neutrophils per rat versus 0.7±0.5×106in control animals), which disappeared by 24 hours. Maximal levels of CXC chemokines were detected 1 hour after Ang II injection (577±224 pmol/L cytokine-inducible neut…
On the mechanism of action of phenylephrine in rat atrial heart muscle
1994
Both in rat left atrial heart and in aortic smooth muscle preparations, phenylephrine (PE) caused a concentration-dependent increase in force of contraction (FC) in the presence of atenolol (10 mumol/l), which was antagonized by phentolamine, prazosin and WB 4101 in a competitive manner. The pA2 values of the antagonists in the cardiac tissue were 10-20fold lower than those in the rat thoracic aorta. In the spontaneously beating right atrium, PE exerted a positive chronotropic action, which was not significantly antagonized by phentolamine or prazosin. It is therefore assumed that the effects of phenylephrine in the left atrium and in the aorta are mediated by different subtypes of alpha 1-…
Synthesis of fjord region tetraols and their use in hepatic biotransformation studies of dihydrodiols of benzo[c]chrysene, benzo[g]chrysene and diben…
1998
Metabolic activation of the racemic benzo[c]chrysene-trans-9,10-, benzo[g]chrysene-trans-11,12- and dibenzo[a,l]pyrene-trans-11,12-dihydrodiols to fjord region syn- and anti-dihydrodiol epoxides by microsomes of Aroclor 1254-treated Sprague-Dawley rats has been examined. Since the fjord region dihydrodiol epoxides were hydrolytically unstable under the experimental conditions, their enzymatic formation was determined by analyzing the tetraols as their products of acidic hydrolysis upon addition of perchloric acid. The various stereoisomeric tetraols formed were separated by HPLC and identified by co-chromatography with authentic tetraols, which had been prepared by acidic hydrolysis of synt…
Hepatoprotective and anti-inflammatory effects of total flavonoids of Qu Zhi Ke (peel of Citrus changshan-huyou) on non-alcoholic fatty liver disease…
2019
Abstract Background Citrus flavonoids, consisting of naringin, narirutin, neohesperidine, etc., have therapeutic activities for the treatment of lipometabolic disorders. The peel of Citrus changshan-huyou (Qu Zhi Ke, QZK) is a new source of flavonoids, but attracted little attention so far. Hypothesis QZK should possess therapeutic effects against lipometabolic disorders due to the flavonoids it contains. Study design In this study, we extracted and purified the flavonoids of QZK (TFCH) and established an obesity-induced non-alcoholic fatty liver disease (NAFLD) model of rats. TFCH was given orally for 8 weeks, and its anti-NAFLD effects and potential mechanism were evaluated. Methods The f…
Analgesic and thermic effects, and cerebrospinal fluid and plasma pharmacokinetics, of intracerebroventricularly administered morphine in normal and …
1998
Abstract The relationship between asthma and opioids has barely been investigated. This study examines whether active sensitization of rats changes the analgesic and thermic effects of intracerebroventricular morphine or the pharmacokinetics of the drug. Morphine (5, 10 and 20 μg) was given intracerebroventricularly to sensitized (active immunization to ovalbumin and Al(OH)3 then airway challenge with ovalbumin after 12 days) and normal (i.e. non-sensitized) male Sprague-Dawley rats. The tail-flick latencies and changes in colon temperature were determined before morphine injection and at 30 min intervals for a period of 300 min afterwards. Results were expressed as the area under the time-…
Influence of massed and distributed context preexposure on contextual fear and Egr-1 expression in the basolateral amygdala
2007
Preexposure to the conditioning context can influence the expression of context-conditioned fear. We used behavioral and early growth response gene (egr-1) assays in rats to study the effects of massed and distributed context preexposure on context-conditioned fear. The results demonstrated that massed context preexposure impaired acquisition of contextual fear, an effect here referred to as delayed shock deficit. Spaced context preexposure produced similar inhibitory effects. Significantly, the introduction of a brief change of context prior to conditioning completely reversed the deficit induced by massed, but not by distributed, context preexposure. This reversibility was inversely relat…
A Method for the Cryopreservation of Liver Parenchymal Cells for Studies of Xenobiotics
1993
Abstract An optimized computer-controlled freezing protocol for the cryopreservation of rat liver parenchymal cells was developed. The best survival rates were obtained when a slow cooling rate was used and when the supercooling was interrupted with a shock cooling to initiate ice nucleation. Ten percent dimethyl sulfoxide was added and removed gradually for best results. Thawed rat liver parenchymal cells had a viability, as judged by trypan blue exclusion, of 69% (SD = 6) versus 82% (SD = 7) for freshly isolated cells. The content and activities of the xenobiotic metabolizing enzymes, cytochrome P450. UDP-glucuronosyl transferase, and microsomal and cytosolic epoxide hydrolase, were not a…
The inhibition by flavonoids of 2-amino-3-methylimidazo[4,5-f]quinoline metabolic activation to a mutagen: a structure-activity relationship study.
1997
The mutagenicity of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) in Salmonella typhimurium TA98 is inhibited by flavonoids with distinct structure-antimutagenicity relationships (Edenharder, R., I. von Petersdorff I. and R. Rauscher (1993). Antimutagenic effects of flavonoids, chalcones and structurally related compounds on the activity of 2-amino-3-methylimidazo[4,5-f]quinoline (IQ) and other heterocyclic amine mutagens from cooked food, Mutation Res., 287, 261-274). With respect to the mechanism(s) of antimutagenicity, the following results were obtained here. (1) 7-Methoxy- and 7-ethoxyresorufin-O-dealkylase activities in rat liver microsomes, linked to cytochrome P-450-dependent 1A1 and…
Rapid cloning of cDNA ends polymerase chain reaction of G-protein-coupled receptor kinase 6: an improved method to determine 5′- and 3′-cDNA ends
1999
Abstract Rapid cloning of 5′- and 3′-cDNA ends polymerase chain reaction (5′-/3′-RACE-PCR) is useful to determine unknown 5′- and 3′-cDNA termini. Even if the method can yield complete cDNA sequences within a couple of days, the RACE procedure bears some characteristic traps and often results in amplification of unspecific PCR-products. Here we used improved 5′- and 3′-RACE-PCR protocols to obtain the complete cDNA sequence of the G-protein-coupled receptor kinase 6 (GRK6) from a rat brain cDNA library. The use of an anchored oligo-(dT) 16 -V-primer in the cDNA synthesis, the addition of single-sided PCR steps prior to the RACE-PCRs and the optimization of the dA-tailing reaction conditions…