自引率: 3.9%
被引量: 15506
通过率: 暂无数据
审稿周期: 1.24
版面费用: 暂无数据
国人发稿量: 65
投稿须知/期刊简介:
Toxicology Letters serves as a multidisciplinary forum for research in all areas of toxicology. The prime aim is rapid publication of research letters with sufficient importance, novelty and breadth of interest. In addition to research letters, papers presenting hypotheses and commentaries addressing current issues of immediate interest to other investigators are invited. Mini-reviews in various areas of toxicology will also be published. A new feature is the provision of a forum for the discussion and interpretation of data published in the journal. Clinical, occupational and safety evaluation, legal, risk and hazard assessment, impact on man and environment studies of sufficient novelty to warrant rapid publication will be considered. The final pages of each issue will provide information on forthcoming meetings, symposia and workshops.
期刊描述简介:
Toxicology Letters serves as a multidisciplinary forum for research in all areas of toxicology. The prime aim is rapid publication of research letters with sufficient importance, novelty and breadth of interest. In addition to research letters, papers presenting hypotheses and commentaries addressing current issues of immediate interest to other investigators are invited. Mini-reviews in various areas of toxicology will also be published. A new feature is the provision of a forum for the discussion and interpretation of data published in the journal. Clinical, occupational and safety evaluation, legal, risk and hazard assessment, impact on man and environment studies of sufficient novelty to warrant rapid publication will be considered. The final pages of each issue will provide information on forthcoming meetings, symposia and workshops.
-
Hypoxic inhibition of 3-methylcholanthrene-induced CYP1A1 expression is independent of HIF-1alpha.
Hypoxia-inducible factor-1alpha (HIF-1alpha) and aryl hydrocarbon receptor (AhR) both require dimerization with AhR nuclear translocator (ARNT) to initiate transcription of their respective target genes. It has been proposed that competition for ARNT results in decreased targeting of AhR to cytochrome P450 1A1 (CYP1A1) under hypoxia. We established primary cultures of HIF-1alpha null hepatocytes to examine the interaction between HIF-1alpha and AhR signaling. Gene expression of known HIF targets phosphoglycerate kinase (PGK), vascular endothelial growth factor (VEGF) and glucose transporter-1 (GLUT-1) increased under hypoxia, but was reduced in the HIF null cultures. Concomitant treatment of cultures with hypoxia (1% O2) and 3-methylcholanthrene (an AhR ligand) did not significantly alter HIF target gene expression. Furthermore, enzymatic activity and transcription of CYP1A1 was inhibited by hypoxia in HIF-1alpha null cultures, indicating that HIF-1alpha is not directly involved in negative regulation of AhR signaling.
被引量:- 发表:2005
-
Role of corticosterone in ethyl carbamate-induced immunosuppression in female BALB/c mice.
:We have recently demonstrated that the antibody response to the T-cell-dependent antigen, sheep red blood cells (SRBCs), was suppressed by ethyl carbamate in female BALB/c mice. At the same doses, ethyl carbamate decreased in the numbers of splenic macrophages, B cells, total T cells, CD4(+) T cells and CD8(+) T cells. In addition, the serum level of corticosterone was increased dose-dependently. To investigate the possible role of corticosterone in ethyl carbamate-induced immunosuppression, the antibody response to SRBCs and the subpopulation changes of splenocytes and thymocytes were determined in naive, sham-operated and adrenalectomized (ADX) female BALB/c mice. When the mice were treated intraperitoneally with 400 mg/kg ethyl carbamate, the antibody response was significantly suppressed by ethyl carbamate in naive and sham-operated mice in accompanying the decrease in spleen and thymus weights and/or the increase in the level of serum corticosterone. Meanwhile, the antibody response was not suppressed by ethyl carbamate in the ADX mice. The splenic numbers of total cells, macrophages, B and T cells, and CD4(+) cells were decreased by ethyl carbamate in naive and sham-operated mice. Meanwhile, each cell number was comparable with control in the ADX mice. The flow cytometric analyses on thymocytes did not show obvious differences as seen in the spleen. Finally, when the ADX mice were treated intraperitoneally with 25 mg/kg corticosterone, the antibody response was significantly suppressed. Taken together, our present results suggested that corticosterone might be, at least partially, responsible for ethyl carbamate-induced immunosuppression in female BALB/c mice.
被引量:1 发表:2001
-
Cypermethrin-induced oxidative stress in rat brain and liver is prevented by vitamin E or allopurinol.
:Considering that the involvement of reactive oxygen species (ROS) has been implicated in the toxicity of various pesticides, this study was designed to investigate the possibility of oxidative stress induction by cypermethrin, a Type II pyrethroid. Either single (170 mg/kg) or repeated (75 mg/kg per day for 5 days) oral administration of cypermethrin was found to produce significant oxidative stress in cerebral and hepatic tissues of rats, as was evident by the elevation of the level of thiobarbituric acid reactive substances (TBARS) in both tissues, either 4 or 24 h after treatment. Much higher changes were observed in liver, increasing from a level of 60% at 4 h up to nearly 4 times the control at 24 h for single dose. Reduced levels (up to 20%) of total glutathione (total GSH), and elevation of conjugated dienes ( approximately 60% in liver by single dose at 4 h) also indicated the presence of an oxidative insult. Glutathione-S-transferase (GST) activity, however, did not differ from control values for any dose or at any time point in cerebral and hepatic tissues. Pretreatment of rats with allopurinol (100 mg/kg, ip) or Vitamin E (100 mg/kg per day, ig, for 3 days and a dose of 40 mg/kg on the 4th day) provided significant protection against the elevation of TBARS levels in cerebral and hepatic tissues, induced by single high dose of oral cypermethrin administration within 4 h. Thus, the results suggest that cypermethrin exposure of rats results in free radical-mediated tissue damage, as indicated by elevated cerebral and hepatic lipid peroxidation, which was prevented by allopurinol and Vitamin E.
被引量:41 发表:2001
-
Synergistic effects of peroxynitrite on arecoline-induced cytotoxicity in human buccal mucosal fibroblasts.
:Epidemiological studies have demonstrated a clear association between betel nut chewing and an increased risk for oral mucosal lesions. Arecoline, the most abundant betel alkaloid, is considered the most important etiologic factor in betel nuts. In addition, most betel nut chewers are also smokers. In order to elucidate the potential toxicological implications of interactions of arecoline and peroxynitrite (a reaction product of cigarette smoking), cell viability, and cellular levels of glutathione (GSH) were investigated, using cultured human buccal mucosal fibroblasts. At a concentration higher than 0.8 mM, arecoline was cytotoxic to buccal mucosal fibroblasts in a concentration- and time-dependent manner. Arecoline also depleted intracellular GSH in a dose-dependent manner (P<0.05). The addition of extracellular peroxynitrite acted as a synergistic effect on the arecoline-induced cytotoxicity (P<0.05). Furthermore, at a concentration of 0.8 mM, arecoline depleted intracellular GSH by about 42%, while 2 mM peroxynitrite enhanced the arecoline-depleted GSH level further to 86% as compared with the control. During GSH depletion, arecoline may render the human buccal mucosal fibroblasts more vulnerable to other reactive agents within cigarette smoking. Taken together, we suggest that people who combine the habits of betel nut chewing with cigarette smoking could be more susceptible to oral mucosal damage than betel quid chewing alone.
被引量:3 发表:2000
-
Effects of pretreatment with SKF-525A on triphenyltin metabolism and toxicity in mice.
:The effects of cytochrome P-450 inhibition by alpha-phenyl-alpha-propylbenzeneacetic acid 2-[diethylamino]-ethyl ester hydrochloride (SKF-525A), which inhibits the activity of a number of cytochrome P-450s, on triphenyltin metabolism and toxicity in mice were studied. At 24 h after triphenyltin administration, the triphenyltin levels in the tissues of SKF-525A-pretreated mice were about three times of those in the tissues of SKF-525A-untreated mice and the ratio of metabolites to parent triphenyltin in the tissues of SKF-525A-pretreated mice was lower than those in the tissues of SKF-525A-untreated mice. These data indicate that the pretreatment of SKF-525A decelerated the triphenyltin metabolism and increased triphenyltin accumulation in the tissues of mice. Although triphenyltin did not affect plasma glucose levels of in the SKF-525A-untreated mice, the triphenyltin produced marked hyperglycemia in SKF-525A-pretreated mice. These results suggest that the inhibition of cytochrome P-450 system enzymes by SKF-525A affects the metabolism and toxicity of triphenyltin and has a key role in inducing the hyperglycemic action of triphenyltin, i.e. by increasing triphenyltin accumulation in the mice.
被引量:1 发表:2000