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1.
The aim of this study was to evaluate the lead toxic effects on the stress parameters and immune responses of Sebastes schlegelii. Juvenile rockfish, S. schlegelii (mean length 14.2 ± 1.9 cm, and mean weight 57.3 ± 5.2 g) were exposed for 4 weeks with the different levels of dietary lead (Pb2+) at 0, 30, 60, 120 and 240 mg/L. The plasma cortisol and heat shock protein 70 was evaluated as stress indicators. The plasma cortisol of S. schlegelii was significantly increased in response to the dietary lead exposure over 60 mg/kg at 2 weeks. After 4 weeks, the significant increase in the plasma cortisol was observed at 30 and 60 mg/kg, but the level was decreased over 120 mg/kg. The heat shock protein 70 of S. schlegelii was also notably elevated over 60 mg/kg for 4 weeks. In the immune response, the immunoglobulin M of S. schlegelii was considerably increased over 120 mg/kg for 4 weeks. A significant increase was observed in lysozyme activity. The plasma lysozyme activity of S. schlegelii was elevated over 120 mg/kg after 2 weeks and 60 mg/kg after 4 weeks, and kidney lysozyme activity was also increased at 240 mg/kg after 2 weeks and over 120 mg/kg after 4 weeks. The results indicate that dietary Pb exposure can cause a significant stress and immune stimulation of S. schlegelii.  相似文献   

2.
Lead (Pb) is considered to be a multi-target toxicant. The present study was undertaken to evaluate the protective effect of aqueous extract of Corchorus olitorius leaves against Pb-acetate induced toxic manifestation in blood, liver, kidney, brain and heart of Wistar rats. The Pb-acetate (5 mg/kg body weight) treated rats exhibited a significant inhibition of co-enzymes Q, antioxidant enzymes and reduced glutathione levels in the tissues. In addition, the extent of lipid peroxidation, DNA fragmentation and haematological parameters were significantly altered in the Pb-acetate treated rats as compared to control. Simultaneous administration of test extract (25, 50 and 100 mg/kg body weight), could significantly restore the biochemical and haematological parameters near to the normal status through antioxidant activity and/or by preventing bioaccumulation of Pb within the tissues of experimental rats. Presence of substantial quantity of phenolics and flavonoids in the extract may be responsible for the observed protective role against Pb-intoxication.  相似文献   

3.
Phthalates as well as di-(2-ethylhexyl) adipate (DEHA) are used as plasticizers in diverse applications and are of toxicological concern.The study was conducted with a study population of 25 German subjects aged between 15 and 21 months. Overall, 16 phthalates and DEHA were measured by gas chromatography–mass spectrometry in a total of 171 duplicate diet samples collected over 7 consecutive days, and 20 phthalate metabolites were analyzed in the urine samples collected over 7 consecutive days using a liquid chromatography–tandem mass spectrometry method.The median “high” daily dietary intake based on 95th percentiles was 4.66 μg/kg b.w. for di-2-ethylhexyl phthalate (DEHP), 1.03 μg/kg b.w. for di-isobutyl phthalate (DiBP), and 0.70 μg/kg b.w. for di-n-butyl phthalate (DnBP), and 1.0 μg/kg b.w. for DEHA. The “high” daily total intake from biomonitoring data was 4.9 μg/kg b.w. for DEHP, 2.2 μg/kg b.w. for DnBP, 3.9 μg/kg b.w. for DiBP, and 2.6 μg/kg b.w. for di-isononyl phthalate.The comparison of the two intake estimates indicates that the dominant intake source of DEHP was food ingestion, whereas other sources considerably contributed to the total intake of other phthalates. Using our “high” intake scenario, none of the analyzed phthalates reached the recommended tolerable daily intake levels.  相似文献   

4.
BackgroundCytochrome P450 3A (CYP3A) subfamily is involved in the metabolism of xenobiotics (e.g., drugs) and endogenous substances (e.g., steroids). The aim of the present study was to investigate the influence of classic and atypical neuroleptics on the level and activity of CYP3A in rat liver, measured as a rate of testosterone 2β- and 6β-hydroxylation.MethodsThe reactions were studied in control liver microsomes in the presence of neuroleptics, as well as in the microsomes of rats treated intraperitoneally (ip) with pharmacological doses of the drugs (promazine and thioridazine 10 mg/kg; chlorpromazine 3 mg/kg; haloperidol 0.3 mg/kg; risperidone 0.1 mg/kg; sertindole 0.05 mg/kg) for one day or two weeks (twice a day), in the absence of the neuroleptics in vitro.ResultsThe investigated neuroleptics added in vitro to control liver microsomes produced a moderate or week inhibitory effects on CYP3A activity. After one-day exposure of rats to neuroleptics, only chlorpromazine significantly increased the activity of CYP3A. Chronic treatment of rats with thioridazine diminished the protein level and activity of CYP3A, while risperidone induced this enzyme.ConclusionThe observed changes in the CYP3A expression after prolonged exposition to neuroleptics suggest their influence on the enzyme regulation.  相似文献   

5.
The uptake of Pb(II) from the aqueous solution by Coffee Husk Biomass Waste (CHBW) as a green low cost solid phase adsorbent was critically studied. The chemical composition and the surface morphology of the CHBW were determined and fully characterized by FESEM-EDX. In batch mode, the effect of various analytical parameters e.g. adsorbent dose, contact time and analyte concentration on lead(II) ions retention by the biomass CHBW was performed. The adsorption equilibrium of Pb(II) ions was achieved after 60 min with very high percentage 98%, and an adsorption capacity of 19.02 mg/g lead towards the adsorbent was determined. Sorption kinetics data was fitted well with pseudo-second-order model with good correlation coefficient (R2 = 1) and (qe,cal) 19.23 mg/g, (eqe,exp) 19.07 mg/g. The sorption isotherm fitted better with the Freundlich model (R2 is close to the unity). The Langmuir gives maximum adsorption capacity (qmax) of Pb(II) was 37.04 mg/g. These results indicated that, the coffee husk is an efficient, sustainable, and low-cost adsorbent for Pb(II) uptake from wastewater.  相似文献   

6.
《Antiviral research》2011,89(3):276-280
Efficacy of combination of the intramuscularly administered neuraminidase (NA) inhibitor, peramivir, and the orally administered M2 ion channel blocker, rimantadine was evaluated in mouse influenza A/Victoria/3/75 (H3N2) model. Mice were challenged with a sub-lethal virus dose (0–40% mortality in placebo group) and changes in body weights were analyzed by three-dimensional effect analysis to assess mode of drug interactions.Compounds were administered in a 5-day treatment course starting 1 h before viral inoculation. The peramivir and rimantadine doses ranged from 0.3–3 mg/kg/d and 5–30 mg/kg/d, respectively. The maximum mean weight loss of 5.19 g was observed in the vehicle-infected group on day 10. In the 1 and 3 mg/kg/d peramivir monotherapy groups, the weight losses were 4.3 and 3.55 g, respectively. In the rimantadine monotherapy group, the weight losses were 3.43, 2.1, and 1.64 g for the 5, 10, and 30 mg/kg/d groups, respectively. Combination of 1 mg/kg/d peramivir with 5 and 10 mg/kg/d rimantadine produced weight losses of 1.69 and 0.69 (p < 0.05 vs. vehicle and individual agent), respectively, whereas the combination of 3.0 mg/kg/d peramivir with 10 and 30 mg/kg/d rimantadine did not show any weight loss (p < 0.05 vs. vehicle and individual agent). The three-dimensional analysis of the weight loss for the majority of the drug combinations of peramivir and rimantadine tested demonstrated synergistic antiviral effects.  相似文献   

7.
Flubendazole, in a new formulation with high systemic bioavailability, has been proposed as a macrofilaricide against filarial diseases.To investigate embryotoxic activity, the new flubendazole formulation was administered orally to Sprague Dawley rats at 2, 3.46, 6.32 mg/kg/day on gestation day (GD) 9.5 and 10.5. Embryos/fetuses were evaluated on GD 11.5, 12.5 or 20.At 6.32 mg/kg/day (Cmax = 0.801 μg/mL after single administration), flubendazole initially induced an arrest of embryonic development followed by a generalized cell death that led to 100% embryolethality by GD 12.5.At 3.46 mg/kg/day (Cmax = 0.539 μg/mL after single administration), flubendazole markedly reduced embryonic development by GD 12.5 without causing cell death. On GD 20, 80% of fetuses showed malformations.At 2 mg/kg/day (Cmax = 0.389 μg/mL after single administration), it did not interfere with rat embryofetal development.  相似文献   

8.
This study evaluated antioxidant, anti-inflammatory, anti-cholinesterase and cytotoxic activities of extracts with different polarities (hexane, dichloromethane, ethyl acetate, ethanol and methanol) obtained from Punica granatum leaves. Total phenolics (8.8–127.3 mg gallic acid equivalent/g dry weight), flavonoids (1.2–76.9 mg quercetin equivalent/g dry weight), tannins (63.7–260.8 mg catechin equivalent/kg dry weight) and anthocyanins (0.41–3.73 mg cyanidin-3-glucoside equivalent/g dry weight) of different extracts were evaluated. The methanolic extract presented a good IC50 by DPPH and ABTS assays (5.62 and 1.31 mg/l respectively). The strongest 5-lipoxygenase (5-LOX), acetylcholinesterase (AChE) and butyrylcholinesterase (BuChE) inhibition activities were obtained for the ethanol extract (IC50 values of 6.20, 14.83 and 2.65 mg/l, respectively) and the best cytotoxic activity against MCF-7 cells was obtained for the methanol extract (IC50 = 31 mg/l). These important biological activities showed that P. granatum leaves could be a potential source of the active molecules intended for applications in pharmaceutical industry, but only after additional in vivo experiments.  相似文献   

9.
The degree of accumulation of Cd and Pb in the brains, spleens, lungs, hearts, livers and kidneys of adult Wistar rats was compared both for separate (Cd or Pb) and combined (Cd + Pb) oral exposure. In addition, the metals were administered either with liquids or with solid feed. Rats were exposed to low doses of metals (7 mg Cd and 50 mg Pb/kg feed or L of distilled water) over 6 or 12 weeks. In total the organs of rats accumulated about 0.3–0.5% Cd and 0.4–0.6% Pb supplied with food or drink. The presented studies demonstrated that the distribution of Cd and Pb in the organs is affected by: the type of exposure (separate or combined), the source of metals (feed or drinks) and the duration of exposure. It was found that simultaneous exposure to low doses of Cd and Pb supplied with food is much more hazardous than exposure to such metals supplied with water.  相似文献   

10.
Combined effects of oxytetracycline (OTC) and Pb on lysosomal membrane stability and coelomocyte apoptosis of earthworm were studied in the paper. Compared with control, the lysosomal membrane stability decreased and coelomocyte apoptosis increased in the treatments of single OTC and Pb contamination. As for compound pollution, combined effect of (5 mg/kg OTC + 50 mg/kg Pb) treatment on earthworm lysosomal was synergistic (except 28 d). However, it was antagonistic at higher concentration of (10 mg/kg OTC + 50 mg/kg Pb) and (20 mg/kg OTC + 50 mg/kg Pb) treatment. In addition, coelomocyte apoptosis of earthworm decreased significantly compared with single OTC, indicating an antagonistic reaction. And joint toxicity of OTC and Pb decreased significantly with the increasing OTC concentration.  相似文献   

11.
BackgroundQUAN-0808 (6-(4-chlorophenoxy)-tetrazolo[5,1-a]phthalazine), a new phthalazine tetrazole derivative, was evaluated for the anti-inflammatory and analgesic effects.MethodsXylene-induced ear edema, carrageenan (Carr)-induced paw edema, and acetic acid-induced capillary permeability hyperactivity in mice were used to assess the anti-inflammatory effect; acetic acid-induced writhing and hot plate responses for the analgesic activity.ResultsIn the present study, QUAN-0808 (100, 200, 400 mg/kg) and indomethacin (Indo) significantly decreased xylene-induced ear edema by 33.3, 37.5, 46.6, and 45.1%, respectively, decreased Carr-induced paw edema at 1, 2, 4 h after Carr injection, and decreased the prostaglandin E2 (PGE2) and nitric oxide (NO) levels on the edema paw at 4 h after Carr injection; QUAN-0808 (100, 200, 400 mg/kg), and aspirin (Asp, 200 mg/kg) significantly decreased Evans blue exudation in acetic acid-induced capillary permeability hyperactivity model by 26.7, 28.7, 32.3 and 29.1%, respectively, and decreased the numbers of acetic acid-induced writhing response in 15 min by 40.4, 53.6, 66.4, and 64.5%, respectively. Morphine (10 mg/kg) significantly increased the latency of the hot plate response by 136.5,117.4,67.5, and 22.7%, respectively, at 30, 60, 90, 120 min after intraperitoneal injection of morphine; however, QUAN-0808 (100, 200 and 400 mg/kg) did not produce significantly antinociceptive effects in the hot plate test, suggesting that its antinociceptive action occurs via peripheral rather than a central-acting mechanism.ConclusionsThese results show that QUAN-0808 produced potential anti-inflammatory and peripheral antinociceptive effects, and indicated that the antinociceptive effects of QUAN-0808 were related to its anti-inflammatory activity in a dose-dependent manner. Therefore, as inflammation is a peripheral process, it is suggested that QUAN-0808 exerted peripheral effects. The peripheral effect mechanisms of QUAN-0808 may be related to a decrease in the production of PGE2, NO, bradykinin and other inflammatory mediators.  相似文献   

12.
Acrylamide (ACR) is a relatively potent neurotoxicant. The ingestion of carbohydrate-containing foods cooked at high temperature exposes humans to low levels of ACR virtually daily. At relatively high levels of exposure (i.e., sub-chronic through chronic levels of exposure of ≥ 20 mg/kg body weight/day), ACR has been shown in both rats and humans to produce a variety of effects on the nervous system. The possibility that chronic dietary exposure to ACR might produce brain toxicity which could impede the development of learning skills is a question of current concern. This research evaluated the effects of ACR on learning task performance in Fischer 344 rats exposed daily beginning prenatally and continuing throughout the lifespan. Dams were gavaged with ACR since implantation [gestation day (GD) 6] with 0, 0.1, 0.3, 1.0 or 5.0 mg/kg/day through parturition. Gavaging continued at the same doses to pups through weaning on post-natal day (PND) 22 after which dosing continued via their drinking water. One male and one female per litter (8–9 per treatment group) were tested. Using an incremental repeated acquisition (IRA) task to assess learning ability, ACR-exposed Fischer 344 rats exhibited altered performance by 4 months of age. From approximately 1–8 months of age (through ~ PND 240), over 52 testing sessions, a significant treatment effect was found on percent task completed (PTC), with Tukey's post-hoc test (P < 0.05) indicating a significantly lower PTC for the 5.0 mg/kg/day group compared to controls. While there was no treatment effect on accuracy (P = 0.53), a significant decrease in response rate was seen at 5.0 mg/kg/day, suggesting that the noted decrease in PTC was due to a decrease in rate of responding, not to an effect on accuracy of task solution. Previous findings in these same animals performing a progressive ratio task for the assessment of motivation, as well as a range of tests of motoric function, suggest that this decreased response rate could be due to subtle motoric effects, or possibly due to decreases in psychomotor speed, but is most likely due to motivational effects.  相似文献   

13.
The present study evaluates protective effects of naringin against paraquat (PQ)-induced acute lung injury (ALI) and pulmonary fibrosis in mice. Survival probability against PQ intoxication was tested by a single intraperitoneal injection of PQ. Results showed that survival rates of mice exposed to PQ only (50 mg/kg within 7 days) were much lower than that in mice daily treatment with NAC or naringin. Moreover, protection against PQ-induced ALI was tested by daily pretreatment mice with saline, NAC or naringin for 3 days before PQ (30 mg/kg, i.p.). Results showed that increase in leukocytes infiltration and overexpressions of TNF-α and TGF-β1 caused by 8 h of PQ exposure were dose-dependently ameliorated by naringin. Furthermore, protection against PQ-induced pulmonary fibrosis was tested by pretreatment mice with PQ (20 mg/kg, i.p.), and then daily administration with saline, NAC or naringin for prolonged 21 days. Results showed that naringin of 60 and 120 mg/kg significantly reduced PQ-induced upregulations of TNF-α, TGF-β1, MMP-9 and TIMP-1, levels of pulmonary malonaldehyde and hydroxyproline, as well as pulmonary fibrosis deposition, while increased activities of SOD, GSH-Px and HO-1. These results indicated that naringin had effective protection against PQ-induced ALI and pulmonary fibrosis.  相似文献   

14.
Nicotinamide N-methyltransferase (NNMT), which converts nicotinamide (NA) to 1-methylnicotinamide (MNA), is up-regulated in the cirrhotic liver. Because MNA displays PGI2-dependent anti-inflammatory effects, the up-regulation of NNMT may play a regulatory role in liver inflammation. In the present work, we analyzed changes in NNMT activity in the liver and concomitant changes in the concentration of endogenous MNA in plasma in T-cell dependent hepatitis induced by concanavalin A (ConA) in BALB/c mice. Furthermore, we tested whether exogenous MNA possessed a protective effect against ConA-induced hepatitis. Development of liver injury induced by ConA (10 mg/kg, iv) was characterized by measurements of plasma concentration of alanine aminotransaminase (ALT), inflammatory cytokines (IFNγ and TNFα) and by histopathological examination. ConA-induced hepatitis was characterized by an early activation of inflammatory cytokines (IFNγ; from below 0.05 ng/ml to 23.72 ± 8.80 ng/ml; TNFα; from 0.07 ± 0.01 ng/ml to 0.71 ± 0.12 ng/ml, 2 h after ConA), an elevation of ALT (from 40.65 ±3.2 U/l to 5,092.20 ± 1,129.05 U/l, 8 h after ConA) and by morphological signs of severe liver inflammation and injury (24 h after ConA). In mice injected with ConA, NNMT activity in the liver was up-regulated approximately 2-fold to 3-fold, 8–24 h after ConAinjection. The concentration of MNA and its metabolites (Met-2PY and Met-4PY) in plasma were elevated approximately 2-fold 8 h after ConA injection. Exogenous MNA (100 mg/kg, iv) diminished ConA-induced liver injury, and this effect was reversed by an antagonist of the prostacyclin receptor, RO 3244794 (10 mg/kg,po). In conclusion, the present study demonstrated that hepatic NNMT activity and MNA concentration in plasma significantly increased during the progression of ConA-induced hepatitis in mice. This response may play a hepatoprotective role compatible with the PGI2-releasing properties of MNA.  相似文献   

15.
Aminocandin (IP960; HMR3270; NXL201) is a new echinocandin with broad-spectrum in vitro activity against Aspergillus and Candida spp. We compared the activity of aminocandin with that of amphotericin B (AmB), itraconazole (ITC) and caspofungin (CAS) in murine models of disseminated aspergillosis against three strains of A. fumigatus, two of which were fully susceptible (AF293 and A1163) and one was resistant to ITC (AF91). Mice were rendered temporarily neutropenic or persistently neutropenic with cyclophosphamide and were infected intravenously 3 days later. Temporarily neutropenic mice were treated with either intraperitoneal (i.p.) AmB (5 mg/kg/dose), oral (p.o.) ITC (25 mg/kg/dose), intravenous (i.v.) aminocandin (0.25–10 mg/kg/dose), i.p. aminocandin (1 mg/kg/dose) or solvent control for 9 days. Mice were euthanised 11 days post infection and the kidneys and liver were removed for quantitative culture. Following infection with AF293, only aminocandin 5 mg/kg i.v. yielded 100% survival. Aminocandin 1 mg/kg i.v., AmB 5 mg/kg i.p. or ITC 25 mg/kg p.o. were equivalent (P > 0.05). Aminocandin 5 mg/kg was superior to aminocandin 0.25 mg/kg (P < 0.0001) as well as all controls (P < 0.0001) in reducing mortality. Following infection with AF91, only aminocandin at 5 mg/kg and 1 mg/kg i.v. yielded 100% survival, which was superior to ITC, aminocandin 0.25 mg/kg and controls (all P < 0.0001). In the persistently neutropenic model with A1163, aminocandin, CAS and micafungin (2–10 mg/kg) were all effective at prolonging survival, with some impact on reducing culture burdens, even with alternate-day dosing (4 mg/kg). The only fungicidal regimen was aminocandin 5 mg/kg, which sterilised 40% and 50% of mice following infection with AF293 and AF91, respectively. Aminocandin at doses of ≥1 mg/kg is highly effective in reducing mortality and organ burden in disseminated infection caused by ITC-susceptible and -resistant A. fumigatus.  相似文献   

16.
Anti-oxidative and immunologic effects of the Korea red ginseng (KRG; Panax ginseng) and urushiol (Rhus vernicifera Stokes) on non-alcoholic fatty liver disease (NAFLD) were evaluated. Forty-five rats (five Long-Evans Tokushima Otsuka and 40 Otsuka Long-Evans Tokushima Fatty [OLETF] rats) received chew diets for 10 months; after this period. The OLETF rats were divided into the following four groups according to diet for 2 months: NAFLD (chew), KRG (chew + KRG [200 mg/kg/day]), urushiol (chew + urushiol [0.5 mg/kg/day]), and ursodeoxycholic acid (UDCA) (chew + UDCA [15 mg/kg/day]) groups. Liver function, lipid profiles and anti-oxidant activity of liver and serum, natural killer (NK) cell activity, and pathology were compared. In KRG and urushiol groups, the level of serum triglyceride ([302.0 ± 70.4 and 275.2 ± 63.8] vs. 527.7 ± 153.3 mg/dL) were lower compared with that of NAFLD group (p < 0.05). The levels of HDL-cholesterol (liver tissue: [4.8 ± 0.2 and 4.8 ± 0.5] vs. 4.2 ± 0.2 mg/g) and NK cell activity ([3485 ± 910 and 3559 ± 910] vs. 2486 ± 619 counts) were significantly higher than those of the NAFLD group (p < 0.001). Inflammation with neutrophil infiltration was observed in only two rats in the NAFLD group. These results suggest that 2 months of oral KRG or urushiol administration improves lipid profiles and stimulates NK cell activity, while inhibiting steatohepatitis in OLEFT rats.  相似文献   

17.
Trace exposures to the toxic metals mercury (Hg), cadmium (Cd) and lead (Pb) may threaten human reproductive health. The aim of this study is to generate biologically-plausible hypotheses concerning associations between Hg, Cd, and Pb and in vitro fertilization (IVF) endpoints. For 15 female IVF patients, a multivariable log-binomial model suggests a 75% reduction in the probability for a retrieved oocyte to be in metaphase-II arrest for each μg/dL increase in blood Pb concentration (relative risk (RR) = 0.25, 95% confidence interval (CI) 0.03–2.50, P = 0.240). For 15 male IVF partners, each μg/L increase in urine Cd concentration is associated with an 81% decrease in the probability for oocyte fertilization (RR = 0.19, 95% CI 0.03–1.35, P = 0.097). Because of the magnitude of the effects, these results warrant a comprehensive study with sufficient statistical power to further evaluate these hypotheses.  相似文献   

18.
Four versions of esterified propoxylated glycerols (EPGs) were evaluated for potential genotoxicity using a range of in vitro and in vivo assays. H-EPG-05 HR/SO 9:1, H-EPG-05 soyate, and H-EPG-14 soyate were non-mutagenic in reverse mutation assays (maximum concentration 1000 μg/plate) using Salmonella typhimurium and Escherichia coli. Heated and unheated H-EPG-05 HR/SO 9:1 and EPG-05 HR/ST 45:55 were likewise non-mutagenic in reverse mutation assays in S. typhimurium strains TA98 and TA100 (maximum concentration 5000 μg/plate). H-EPG-05 HR/SO 9:1, H-EPG-05 soyate, and H-EPG-14 soyate, were devoid of mutagenic activity in a mouse lymphoma assay in L5178Y tk +/− cells (maximum concentration 200 μg/plate for H-EPG-05 HR/SO 9:1; 100 μg/plate for H-EPG-05 soyate and H-EPG-14 soyate), and a chromosomal aberration test using human lymphocytes (maximum concentration 50 μg/plate for H-EPG-05 HR/SO 9:1 and H-EPG-05 soyate; 60 μg/plate for H-EPG-14 soyate). All assays were conducted with and without metabolic activation. Additionally, H-EPG-05 HR/SO 9:1, H-EPG-05 soyate, and H-EPG-14 soyate were non-genotoxic in unscheduled DNA synthesis tests in rats (maximum dose 2000 mg/kg). Based on the results of these assays it was concluded that these versions of EPG were not genotoxic under any of the conditions of the assays performed.  相似文献   

19.
BackgroundBehavioral effects of benzodiazepines following repeated exposure vary according to the intrinsic efficacy of the benzodiazepine studied, treatment schedule and the behavioral parameters evaluated.MethodsWe applied the behavioral paradigms of spontaneous locomotor activity, elevated plus maze and grip strength to investigate the sedative, anxiolytic and myorelaxant effect of acute challenge with 2 mg/kg diazepam administered after 14 days of protracted treatment with 0.5, 2 or 10 mg/kg of diazepam. In addition, we studied the effects of everyday handling and intraperito-neal (ip) administration on animal behavior.ResultsTolerance to the sedative effect of 2 mg/kg diazepam ensued after 14 days of protracted treatment with 2 and 10 mg/kg of diazepam. In contrast, treatment with the lowest dose (0.5 mg/kg) of diazepam resulted in potentiation of the sedative effect of acute challenge with 2 mg/kg diazepam thus confounding the detection of the anxiolytic effect of diazepam. A sensitization-like response to the anxiolytic action of 2 mg/kg diazepam was seen after protracted treatment with the intermediate dose (2 mg/kg); however, anxiolytic effect was absent after protracted administration of the highest dose. Partial tolerance to the muscle relaxant effect of 2 mg/kg diazepam ensued after protracted treatment with diazepam regardless of the dose. Daily handling or ip administration did not alter the behavioral response to acute challenge with 2 mg/kg diazepam in all the three behavioral paradigms studied.ConclusionThe presented results showed that behavioral effects of acute challenge with diazepam were differently affected by the dose administered during protracted treatment.  相似文献   

20.
Oxcarbazepine is a representative molecule for a new class of anticonvulsant drugs that can treat alcohol dependence in addition to other disorders. Interestingly, the central mechanism of action in oxcarbazepine is very similar to ethanol, suggesting that these two agents may interact and cause enhanced effects in the central nervous system. In this study, we used a pharmaco-EEG method to examine the influence of oxcarbazepine on the effect of ethanol on the EEG of rabbits (midbrain reticular formation, hippocampus, frontal cortex). Oxcarbazepine was administered po as a single dose (20 mg/kg or 80 mg/kg) or repeatedly at a dose of 40 mg/kg/day for 14 days. Ethanol was injected iv at a dose of 0.8 g/kg 60 min after the administration of oxcarbazepine. Ethanol caused an increase in the low frequencies (0.5–4 Hz) in the recordings, and it caused a marked decrease in higher frequencies (13–30 Hz and 30–45 Hz). Oxcarbazepine altered the EEG pattern in rabbits; this interaction was dependent on the dose of the drug and whether it was administered as a single dose or as multiple doses. Oxcarbazepine administered at a lower dose had a synergistic effect with ethanol in the frontal cortex and midbrain reticular formation, and a similar effect was observed in the hippocampus at a higher dose. Changes in EEG recordings after the administration of oxcarbazepine alone were more pronounced after multiple administrations. The drug decreased the sensitivity of the hippocampus to ethanol, an observation that may be important for the treatment of alcohol addiction.  相似文献   

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