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1.
Summary. Serotonin (5-HT) is a metabolite of tryptophan (TRP). 5-HT has been shown to induce contractions in rat duodenum and ileum. We planned to investigate the in vivo effects of TRP administration on duodenal contractility and ultrastructure together.Two equal groups of adult male Swiss-albino mice were used in the experiments.Controls (CONT) and TRP treated (100mg/kg/24hr in 0.2ml. saline solution ip, 7 days).Body weights were recorded at the beginning and at the end of experiments. Duodenum tissues contractility responses to different concentration of KCl and acethycholine (ACh) were recorded on polygraph. The ultrastructural changes in duodenum observed by transmission electron microscopic (TEM) method and 5-HT levels determined by immunohistochemical method.Body weights decreased and duodenal contractile response of ACh increased significantly by TRP treatment. The duodenal ultrastructural changes in TRP group illustrated partially loss of apical surface and fusion in microvilli. Immunohistochemical detection showed that 5-HT increased by TRP treatment.There is a relation between duodenal contractility increased by TRP treatment and changes in the duodenal tissue 5-HT level and ultrastructure. 相似文献
2.
Ozer C Gönül B Elmas C Erdoüan D Ercan ZS 《Molecular and cellular biochemistry》2005,280(1-2):151-157
Dexfenfluramine is one of the anorectic drugs that suppresses food intake which acts via inhibition of reuptake of serotonin
into brain terminal. Gastrointestinal tract is the main source of peripheral serotonin which is involved in the regulation
of gastrointestinal motility. During the use of anorectic drugs, the antioxidant defence is affected especially by reactive
oxygen species.
The purpose of this study to search: The effect of dexfenfluramine on serotonin levels of ileum and the effect of dexfenfluramine
on ileal contractility and oxidative stress.
Materials and Methods: Twenty-two adult male Swiss-albino mice were divided two groups (1) Control, (2) Dexfenfluramine treated
(i.p. twice a day 0.2 mg kg−1 in 0.2 ml saline solution for 7 days). Animal body weights were recorded at the beginning and at the end of the experimental
period. Ileum tissues contractile responses to different concentrations of KCl and acethycholine were recorded on polygraph.
In the meantime ileal tissue malondialdehyde, a product of lipid peroxidation, and glutathione, endogenous antioxidant levels
were assessed by spectrophotometric methods. Ileal tissue serotonin level determined by immunohistochemical method. Body weights
decrease and ileal contractile response of acethycholine increased significantly by dexfenfluramine treatment. Meanwhile,
ileum glutathione levels decreased and malondialdehyde levels increased in dexfenfluramine treated group. Immunohistochemical
detection showed that ileal serotonin levels increased by dexfenfluramine treatments.
As a conclusion, there is a relationship between increased ileal contractility and oxidant status in dexfenfluramine treated
animals. These effects can be related by increased serotonin levels which is induced by dexfenfluramine in ileum. (Mol Cell
Biochem xxx: 151–157, 2005) 相似文献
3.
Summary. It has been shown in various studies that increase in serotonergic neurotransmission is associated with increased memory consolidation
whereas low brain 5HT impairs memory performance. In the first phase of our study we found that tryptophan (TRP) administration
for 6 weeks increased plasma TRP and whole brain TRP, 5HT and 5HIAA levels. Many brain regions are involved in the learning
process but particularly the hippocampus is known to have key role in learning and memory.
The present study was therefore designed to investigate the effects of TRP loading particularly on hippocampal 5HT metabolism
and cognitive performance in rats. TRP-treated rats demonstrated spatial enhancement as evidenced by a significant decrease
in time to find the hidden food reward in radial arm maze test (RAM). The important finding of the present study was the greater
increase in the 5HT metabolism in hippocampus than in any other brain region of the TRP-treated rats. This increased 5HT metabolism
in the hippocampus emphasizes the involvement of this region in memory process. 相似文献
4.
Guz G Oz E Lortlar N Ulusu NN Nurlu N Demirogullari B Omeroglu S Sert S Karasu C 《Amino acids》2007,32(3):405-411
Summary. Ischemia-reperfusion (I/R) injury is one of the most common causes of renal dysfunction. Taurine is an endogenous antioxidant
and a membrane-stabilizing, intracellular, free beta-amino acid. It has been demonstrated to have protective effects against
I/R injuries to tissues other than kidney. The aim of this study was to determine whether taurine has a beneficial role in
renal I/R injury. Forty Wistar-Albino rats were allocated into four groups as follows: sham, taurine, I/R, and I/R + taurine.
Taurine 7.5 mg/kg was given intra-peritoneally to rats in the groups taurine and I/R + taurine. Renal I/R was achieved by
occluding the renal arteries bilaterally for 40 min, followed by 6 h of reperfusion. Immediately thereafter, blood was drawn
and tissue samples were harvested to measure 1) serum levels of BUN and creatinine; 2) serum and/or tissue levels of malondialdehyde
(MDA), glutathione (GSH), glucose 6-phosphate dehydrogenase (G-6PD), 6-phosphogluconate dehydrogenase (6-PGD) and glutathione
reductase (GSH-red); 3) renal morphology; and 4) immunohistochemical staining for P-selectin. Taurine administration reduced
I/R-induced increases in serum BUN and creatinine, and serum and tissue MDA levels (p < 0.05). Additionally, taurine lessened
the reductions in serum and tissue glutathione levels secondary to I/R (p < 0.05). Taurine also attenuated histopathologic
evidence of renal injury, and reduced I/R-induced P-selectin immunoreactivity (p < 0.05). Overall, then, taurine administration
appears to reduce the injurious effects of I/R on kidney. 相似文献
5.
Kocsy G von Ballmoos P Suter M Rüegsegger A Galli U Szalai G Galiba G Brunold C 《Planta》2000,211(4):528-536
The role of glutathione (GSH) in protecting plants from chilling injury was analyzed in seedlings of a chilling-tolerant
maize (Zea mays L.) genotype using buthionine sulfoximine (BSO), a specific inhibitor of γ-glutamylcysteine (γEC) synthetase, the first enzyme
of GSH synthesis. At 25 °C, 1 mM BSO significantly increased cysteine and reduced GSH content and GSH reductase (GR: EC 1.6.4.2)
activity, but interestingly affected neither fresh weight nor dry weight nor relative injury. Application of BSO up to 1 mM
during chilling at 5 °C reduced the fresh and dry weights of shoots and roots and increased relative injury from 10 to almost
40%. Buthionine sulfoximine also induced a decrease in GR activity of 90 and 40% in roots and shoots, respectively. Addition
of GSH or γEC together with BSO to the nutrient solution protected the seedlings from the BSO effect by increasing the levels
of GSH and GR activity in roots and shoots. During chilling, the level of abscisic acid increased both in controls and BSO-treated
seedlings and decreased after chilling in roots and shoots of the controls and in the roots of BSO-treated seedlings, but
increased in their shoots. Taken together, our results show that BSO did not reduce chilling tolerance of the maize genotype
analyzed by inhibiting abscisic acid accumulation but by establishing a low level of GSH, which also induced a decrease in
GR activity.
Received: 9 November 1999 / Accepted: 17 February 2000 相似文献
6.
Parildar-Karpuzoğlu H Doğru-Abbasoğlu S Balkan J Aykaç-Toker G Uysal M 《Amino acids》2007,32(1):115-119
Summary. We aimed to investigate the effect of decreased taurine levels on endogenous and induced lipid peroxide levels in liver, brain,
heart and erythrocytes as well as prooxidant and antioxidant balance in the liver of rats administered β-alanine (3%, w/v)
in drinking water for 1 month to decrease taurine levels of tissues. This treatment caused significant decreases in taurine
levels of liver (86%), brain (36%) and heart (15%). We found that endogenous and ascorbic acid-, NADPH- and cumene hydroperoxide-induced
malondialdehyde (MDA) levels did not change in the liver, brain and heart homogenates following β-alanine treatment. Also,
H2O2-induced MDA levels remained unchanged in erythrocytes. In addition, we did not observe any changes in levels of MDA, diene
conjugates, glutathione, α-tocopherol, ascorbic acid and the activities of superoxide dismutase, glutathione peroxidase and
glutathione transferase in the liver. According to this, buffering or sequestering capacity of tissues to exogenous stimuli
was not influenced by reduced taurine levels in tissues of rats. 相似文献
7.
Summary. The purpose of this study was to determine whether the γ-aminobutyric acid (GABA) affects the rate of brain protein synthesis
in male rats. Two experiments were done on five or three groups of young rats (5 wk) given the diets containing 20% casein
administrated 0 mg, 25 mg, 50 mg, 100 mg or 200 mg/100 g body weight GABA dissolved in saline by oral gavage for 1 day (d)
(Experiment 1), and given the diets contained 0%, 0.25% or 0.5% GABA added to the 20% casein diet (Experiment 2) for 10 d.
The plasma concentration of growth hormone (GH) was the highest in rats administrated 50 mg and 100 mg/100 g body weight GABA.
The concentration of serum GABA increased significantly with the supplementation groups. The fractional (Ks) rates of protein
synthesis in brain regions, liver and gastrocnemius muscle increased significantly with the 20% casein + 0.25% GABA diet and
still more 20% casein + 0.5% GABA compared with the 20% casein diet. In brain regions, liver and gastrocnemius muscle, the
RNA activity [g protein synthesized/(g RNA·d)] significantly correlated with the fractional rate of protein synthesis. The
RNA concentration (mg RNA/g protein) was not related to the fractional rate of protein synthesis in any organ. Our results
suggest that the treatment of GABA to young male rats are likely to increase the concentrations of plasma GH and the rate
of protein synthesis in the brain, and that RNA activity is at least partly related to the fractional rate of brain protein
synthesis. 相似文献
8.
Summary. Mice were supplemented with β-alanine (3%) in drinking water for one week. β-Alanine intake reduced hepatic taurine levels,
but elevated cysteine levels significantly. Hepatotoxicity of CCl4 in mice fed with β-alanine was decreased as determined by changes in serum enzyme activities. Hepatic glutathione and taurine
concentrations after CCl4 challenge were increased markedly by β-alanine intake. The enhanced availability of cysteine for synthesis of glutathione
and/or taurine appears to account for the hepatoprotective effects of β-alanine against CCl4-induced liver injury. 相似文献
9.
The effect of cold hardening on the accumulation of glutathione (GSH) and its precursors was studied in the shoots and roots
of wheat (Triticum aestivum L.) cv. Cheyenne (Ch, frost-tolerant) and cv. Chinese Spring (CS, moderately frost-sensitive), in a T. spelta L. accession (Tsp, frost-sensitive) and in chro- mosome substitution lines CS (Ch 5A) and CS (Tsp 5A). The fast induction
of total glutathione accumulation was detected during the first 3 d of hardening in the shoots, especially in the frost-tolerant
Ch and CS (Ch 5A). This observation was corroborated by the study of de novo GSH synthesis using [35S]sulfate. In Ch and CS (Ch 5A) the total cysteine, γ-glutamylcysteine (precursors of GSH), hydroxymethylglutathione and GSH
contents were greater during the 51-d treatment than in the sensitive genotypes. After 35 d hardening, when the maximum frost
tolerance was observed, greater ratios of reduced to oxidised hydroxymethylglutathione and glutathione were detected in Ch
and CS (Ch 5A) compared to the sensitive genotypes. A correspondingly greater glutathione reductase (EC 1.6.4.2) activity
was also found in Ch and CS (Ch 5A). It can be assumed that chromosome 5A of wheat has an influence on GSH accumulation and
on the ratio of reduced to oxidised glutathione as part of a complex regulatory function during hardening. Consequently, GSH
may contribute to the enhancement of frost tolerance in wheat.
Received: 24 March 1999 / Accepted: 19 July 1999 相似文献
10.
Summary. Taurine as well as tauret (retinyliden taurine) levels were measured in locust Locusta migratoria compound eyes. HPLC measurements revealed relatively low taurine levels (1.9 ± 0.16 mM) in dark-adapted eyes. Glutamate,
aspartate and glycine levels were 2.0 ± 0.2, 2.7 ± 0.4 and 3.0 ± 0.37 mM, respectively, while GABA was present only in trace
amounts. After about 4 h of light adaptation at 1500–2000 lx, amino acid levels in the compound eye were as follows: taurine,
1.8 ± 0.17 mM; glutamate, no change at 2.1 ± 0.2 mM; aspartate sharply increased to 4.7 ± 0.7 mM; glycine slightly decreased
to 2.8 ± 0.3 mM; and GABA trace levels. In the compound eye of locust Locusta migratoria, the existence of endogenous tauret in micro-molar range was established. In the dark, levels were several times higher compared
with compound eye after light adaptation 1500 lx for 3 h, as estimated by TLC in combination with spectral measurements. Existence
of tauret in compound eye is of special interest because in the compound eye, rhodopsin regeneration is based on photoregeneration. 相似文献
11.
Summary. Increased levels in plasma homocysteine and cysteine, and more recently, decreased levels in cysteinylglycine have been indicated
as a risk factor for vascular diseases. Most assays focused their attention only on homocysteine determination and when also
other thiols were measured, analytical times drastically increased. By modifying our previous method for thiols detection,
we set up a rapid capillary electrophoresis method for the selective quantification of plasma cysteinylglycine, cutting the
analysis time of about 50%. Samples were treated with tri-n-butylphosphine as reducing agent, proteins were precipitated with
trichloroacetic acid and released thiols were successively derivatized by the selective thiol laser-induced fluorescence-labeling
agent 5-iodoacetamidofluorescein and separated by capillary electrophoresis. A baseline separation between peaks was obtained
in about 2 min using 3 mmol/L sodium phosphate/2.5 mmol/L boric acid as electrolyte solution with 75 mmol/L N-methyl-D-glucamine
at pH 11.25 in a 47 cm long capillary with a cartridge temperature of 45 °C. The method application was checked by measuring
plasma Cys-Gly levels in a group of patients affected by retinal vein occlusion (RVO), an important cause of visual loss in
the elderly. The low levels of Cys-Gly found in the RVO patients suggest that these small thiols may have importance in the
disease development.
Authors’ addresses: Dr. Angelo Zinellu, Dr. Ciriaco Carru, Department Biomedical Sciences, Chair of Clinical Biochemistry,
University of Sassari, Viale San Pietro 43/B, 07100 Sassari, Italy 相似文献
12.
To test the hypothesis that the contribution of phosphoribulokinase (PRK) to the control of photosynthesis changes depending
on the light environment of the plant, the response of transgenic tobacco (Nicotiana tabacum L.) transformed with antisense PRK constructs to irradiance was determined. In plants grown under low irradiance (330 μmol m−2 s−1) steady-state photosynthesis was limited in plants with decreased PRK activity upon exposure to higher irradiance, with a
control coefficient of PRK for CO2 assimilation of 0.25 at and above 800 μmol m−2 s−1. The flux control coefficient of PRK for steady-state CO2 assimilation was zero, however, at all irradiances in plant material grown at 800 μmol m−2 s−1 and in plants grown in a glasshouse during mid-summer (alternating shade and sun 300–1600 μmol m−2 s−1). To explain these differences between plants grown under low and high irradiances, Calvin cycle enzyme activities and metabolite
content were determined. Activities of PRK and other non-equilibrium Calvin cycle enzymes fructose-1,6-bisphosphatase, sedoheptulose-1,7-bisphosphatase
and ribulose-1,5-bisphosphate carboxylase-oxygenase were twofold higher in plants grown at 800 μmol m−2 s−1 or in the glasshouse than in plants grown at 330 μmol m−2 s−1. Activities of equilibrium enzymes transketolase, aldolase, ribulose-5-phosphate epimerase and isomerase were very similar
under all growth irradiances. The flux control coefficient of 0.25 in plants grown at 330 μmol m−2 s−1 can be explained because low ribulose-5-phosphate content in combination with low PRK activity limits the synthesis of ribulose-1,5-bisphosphate.
This limitation is overcome in high-light-grown plants because of the large relative increase in activities of sedoheptulose-1,7-bisphosphatase
and fructose-1,6-bisphosphatase under these conditions, which facilitates the synthesis of larger amounts of ribulose-5-phosphate.
This potential limitation will have maintained evolutionary selection pressure for high concentrations of PRK within the chloroplast.
Received: 15 November 1999 / Accepted: 27 January 2000 相似文献
13.
Summary. Glutathione (reduced form GSH and oxidized form GSSG) constitutes an important defense against oxidative stress in the brain,
and taurine is an inhibitory neuromodulator particularly in the developing brain. The effects of GSH and GSSG and glycylglycine,
γ-glutamylcysteine, cysteinylglycine, glycine and cysteine on the release of [3H]taurine evoked by K+-depolarization or the ionotropic glutamate receptor agonists glutamate, kainate, 2-amino-3-hydroxy-5-methyl-4-isoxazolepropionate
(AMPA) and N-methyl-D-aspartate (NMDA) were now studied in slices from the hippocampi from 7-day-old mouse pups in a perfusion system.
All stimulatory agents (50 mM K+, 1 mM glutamate, 0.1 mM kainate, 0.1 mM AMPA and 0.1 mM NMDA) evoked taurine release in a receptor-mediated manner. Both
GSH and GSSG significantly inhibited the release evoked by 50 mM K+. The release induced by AMPA and glutamate was also inhibited, while the kainate-evoked release was significantly activated
by both GSH and GSSG. The NMDA-evoked release proved the most sensitive to modulation: L-Cysteine and glycine enhanced the
release in a concentration-dependent manner, whereas GSH and GSSG were inhibitory at low (0.1 mM) but not at higher (1 or
10 mM) concentrations. The release evoked by 0.1 mM AMPA was inhibited by γ-glutamylcysteine and cysteinylglycine, whereas
glycylglycine had no effect. The 0.1 mM NMDA-evoked release was inhibited by glycylglycine and γ-glutamylcysteine. In turn,
cysteinylglycine inhibited the NMDA-evoked release at 0.1 mM, but was inactive at 1 mM. Glutathione exhibited both enhancing
and attenuating effects on taurine release, depending on the glutathione concentration and on the agonist used. Both glutathione
and taurine act as endogenous neuroprotective effectors during early postnatal life.
Authors’ address: Prof. Simo S. Oja, Brain Research Center, Medical School, FI-33014 University of Tampere, Finland 相似文献
14.
Sepsis is commonly associated with enhanced generation of reactive oxygen metabolites, which lead to multiple organ dysfunction. The aim of this study was to examine the role of melatonin, a potent antioxidant, in protecting the intestinal and bladder tissues against damage in a rat model of sepsis. Sepsis was induced by cecal ligation and perforation (CLP) in Wistar Albino rats. Sham operated (control) and CLP group received saline or melatonin (10 mg/kg, ip) 30 minutes prior to and 6 hours after the operation. Sixteen hours after the surgery, rats were decapitated and the intestinal and urinary bladder tissues were used for contractility studies, or stored for the measurement of malondialdehyde (MDA) content -an index of lipid peroxidation-, glutathione (GSH) levels -a key antioxidant- and myeloperoxidase (MPO) activity- an index of neutrophil infiltration-. Ileal and bladder MDA levels in the CLP group were significantly increased (p < 0.001) with concomitant decreases in GSH levels (p < 0.01 - p < 0.001) when compared to the control group. Similarly, MPO activity was significantly increased (p < 0.001) in both ileum and bladder tissues. On the other hand, melatonin treatment significantly reversed (p < 0.001) the elevations in MDA and MPO levels, while reduced GSH levels were increased back to the control levels (p < 0.01 - p < 0.001). In the CLP group, the contractility of the ileal and bladder tissues decreased significantly compared with controls. Melatonin treatment of the CLP group restored these responses. In this study, CLP induced dysfunction of the ileal and bladder tissue of rats was reversed by melatonin treatment. Moreover, melatonin, as an antioxidant, abolished the elevation in lipid peroxidation products and myeloperoxidase activity, and reduction in the endogenous antioxidant glutathione and thus protected the tissues against sepsis-induced oxidative damage. 相似文献
15.
Non-photochemical quenching of chlorophyll fluorescence (NPQ) and quantum yield of photosystem II (PSII) were studied with
intact mesophyll chloroplasts of maize (Zea mays L.) during the initial minutes of illumination using the pulse-modulated chlorophyll fluorescence technique. Non-photochemical
quenching was rapidly reversible in the dark at any point during illumination, which is indicative of energy-dependent dissipation
of energy (mediated via thylakoid ΔpH changes and ascorbate-dependent synthesis of zeaxanthin). In chloroplasts suspensions
including 15 mM ascorbate in the medium, with addition of oxaloacetate and pyruvate, the PSII yield, rate of reduction of
oxaloacetate and phosphorylation of pyruvate reached a maximum after approximately 2 min of illumination. Under these conditions,
which promote phosphorylation and a decreased ΔpH across the thylakoid membrane, NPQ rose to a maximum after 2–3 min of illumination,
dropped to a minimum after about 6 min, and then increased to a steady-state level. A rather similar pattern was observed
when leaves were illuminated following a 30-min dark period. Providing chloroplasts with higher levels of ascorbate (60 mM),
prevented the transient drop in NPQ. Anaerobic conditions or addition of potassium cyanide caused a decrease in PSII yield,
providing evidence for operation of the ascorbate-dependent Mehler-peroxidase reaction. These conditions also strongly suppressed
the transient drop in NPQ. Dithiothreitol, an inhibitor of violaxanthin de-epoxidase, caused a large drop in NPQ even in the
presence of high levels of ascorbate. The results suggest that the decline of NPQ occurs in response to an increase in lumen
pH after initiation of phosphorylation, that this decline can be suppressed by conditions where ascorbate is not limiting
for violaxanthin de-epoxidase, and that the increase of NPQ after such a decline is the result of development of energy dissipation
in PSII reaction centers.
Received: 13 August 1999 / Accepted: 17 September 1999 相似文献
16.
Nikolic J Stojanovic I Pavlovic R Sokolovic D Bjelakovic G Beninati S 《Amino acids》2007,32(1):127-131
Summary. The existing interrelation in metabolic pathways of L-arginine to polyamines, nitric oxide (NO) and urea synthesis could be
affected in sepsis, inflammation, intoxication and other conditions. The role of polyamines and NO in the toxic effect of
mercury chloride on rat liver function was studied. Administration of mercury chloride for 24 h led to significantly elevated
plasma activities of Alanine transaminase (ALT) and Aspartate transaminase (AST). Malondyaldehyde (MDA) levels were unaffected
(p > 0.05) and arginase activity was significantly decreased (p < 0.05) while nitrate/nitrite production was significantly
elevated (p < 0.001) in liver tissue. Polyamine oxidase (PAO) and diamine oxidase (DAO) activities, enzymes involved in catabolism
of polyamines, were decreased. L-arginine supplementation to intoxicated rats potentiated the effect of mercury chloride on
NO production and it was ineffective on arginase activity.
Results obtained in this study show that mercury chloride-induced toxicity leads to abnormally high levels of ALT and AST
that may indicate liver damage with the involvement of polyamine catabolic enzymes and NO. 相似文献
17.
The effect of extractants on degradation of L-glutamate and L-arginine in the course of shaking and filtration at low temperature 总被引:1,自引:0,他引:1
Summary. The effects of demineralized water (DEMI H2O) and 0.5 M ammonium acetate (0.5 M AAc) on losses of L-glutamic acid and L-arginine in the course of shaking and filtration
at low temperature (6 °C) were tested. The concentration of L-glutamic acid decreased by 6.3% in DEMI H2O and by 4.9% in 0.5 M AAc, whereas the L-arginine concentration decreased by 6.0% (DEMI H2O) and 10.7% (0.5 M AAc). We found a significantly (P < 0.05) higher degradation of L-arginine in 0.5 M AAc compared with that of DEMI H2O. 相似文献
18.
Garcia RF Gazola VA Barrena HC Hartmann EM Berti J Toyama MH Boschero AC Carneiro EM Manso FC Bazotte RB 《Amino acids》2007,33(1):151-155
Summary. Our purpose was to determine the blood amino acid concentration during insulin induced hypoglycemia (IIH) and examine if the
administration of alanine or glutamine could help glycemia recovery in fasted rats. IIH was obtained by an intraperitoneal
injection of regular insulin (1.0 U/kg). The blood levels of the majority of amino acids, including alanine and glutamine
were decreased (P < 0.05) during IIH and this change correlates well with the duration than the intensity of hypoglycemia. On the other hand,
the oral and intraperitoneal administration of alanine (100 mg/kg) or glutamine (100 mg/kg) accelerates glucose recovery.
This effect was partly at least consequence of the increased capacity of the livers from IIH group to produce glucose from
alanine and glutamine. It was concluded that the blood amino acids availability during IIH, particularly alanine and glutamine,
play a pivotal role in recovery from hypoglycemia. 相似文献
19.
Merentie M Uimari A Pietilä M Sinervirta R Keinänen TA Vepsäläinen J Khomutov A Grigorenko N Herzig KH Jänne J Alhonen L 《Amino acids》2007,33(2):323-330
Summary. The markers of oxidative stress and inflammation were studied in acute pancreatitis in transgenic rats exhibiting activated
polyamine catabolism. In addition, the effect of bismethylspermine (Me2Spm) pretreatment, preventing pancreatitis in this model, on these mediators was investigated. Lipid peroxidation was increased
at 6 and 24 h after induction of pancreatitis. These changes as well as the markedly decreased superoxide dismutase activity
at 24 h were abolished by Me2Spm pretreatment. Glutathione level and catalase activity changed transiently, and the effect of Me2Spm was clear at 24 h. Serum inflammatory cytokine levels increased already at 4 h whereas NF-κB was distinctly activated
only at 24 h. Me2Spm prevented the increase in TNF-α and IL-6 while it had no effect on NF-κB activation. These results show that typical inflammatory
and, to a lesser degree, some oxidative stress mediators are involved and beneficially affected by the disease-ameliorating
polyamine analogue in our pancreatitis model. 相似文献
20.
Summary. Heat shock proteins (HSPs) are synthesised by cells subsequent to a stress exposure and are known to confer protection to
the cell in response to a second challenge. HSP induction and decay are correlated to thermotolerance and may therefore be
used as a biomarker of thermal history. The current study tested the temperature-dependent nature of the heat shock response
and characterised its time profile of induction. Whole blood from 6 healthy males (Age: 26 ± (SD) 2 yrs; Body mass 74.2 ±
3.8 kgs; VO2max: 49.1 ± 4.0 ml·kg−1·min−1) were isolated and exposed to in vitro heat shock (HS) at 37, 38, 39, 40, and 41 °C for a period of 90 min. After HS the
temperature was returned to 37 °C and intracellular HSP70 was quantified from the leukocytes at 0, 2, 4, and 6 h after heat
treatment. The concentration of HSP70 was not different between temperatures (P > 0.05), but the time-profile of HSP70 synthesis appeared temperature-dependent. At control (37 °C) and lower temperatures
(38–39 °C) the mean HSP70 concentration increased up to 4 h post HS (P < 0.05) and then returned towards baseline values by 6 h post HS. With in vitro hyperthermic conditions (40–41 °C), the time-profile
was characterised by a sharp rise in HSP70 levels immediately after treatment (P < 0.05 for 40 °C at 0 h), followed by a progressive decline over time. The results suggest a temperature-dependent time-profile
of HSP70 synthesis. In addition, the temperature at which HSP70 is inducted might be lower than 37 °C. 相似文献