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Objective To investigate the changes of caspase 3 activity and the interventional effect of tetrapeptide AC DEVD CHO on sulfur mustard induced apoptosis of lymphocyte. Methods The activity of caspase 3 was detected by fluorospectrophotometry. DNA ladder and apoptosis were detected by DNA agarose gel electrophoresis and flow cytometry. Results Sulfur mustard enhanced the activity of caspase 3 and its polypeptide inhibitor (AC DEVD CHO) partially blocked apoptosis, which was mainly presented as an obscure phenomenon of DNA ladder and a decrease in percentage of apoptosis. Conclusion Sulfur mustard can induce the apoptosis of lymphocyte by means of activating caspase 3. The inhibitor may have an interventional effect on lymphocyte apoptosis induced by sulfur mustard.
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Objective To investigate the manner and molecular mechanism of lymphocyte cytotoxic action induced by sulfur mustard. Methods Lymphocytes were separated from the spleen of Wistar rats and were cultured. DNA strand breaks were detected by fluorospectrophotometry. RT PCR and Western blotting were employed to detect the gene and protein expressions of caspase 3 and its activation. Results Sulfur mustard induced DNA strand breaks in the lymphocytes. Gene and protein expressions of caspase 3 were increased in a time dependent manner. Conclusion Sulfur mustard induces lymphocyte cytotoxic action by means of depending on the expression and activation of caspase 3.
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Objective To investigate the apoptotic effect induced by sulfur mustard on the lymphocytes of the rat spleen,and define the role of caspase-3 during the process.Methods Sulfur mustard was given by intraperitoneal injection in a dose of 3.5mg/kg.The animals were anesthetized and the spleens were harvested at different timepoints after intoxication.The histopathogy of spleen was studied with hematoxylin-eosin staining.Caspase-3 mRNA was detected with RT-PCR.Protein expression of caspase-3 was assayed with Western blotting,lymphocytes of rat spleen were isolated and cultured in vitro and they were challenged with sulfur mustard(100?mol/L).The effect of Ac-DEVD-CHO(a specific inhibitor of caspase-3)on sulfur mustard-induced apoptosis of the lymphocytes cultured in vitro was evaluated.Fluorescent probe labeled with Rhodamine 123 was used to study mitochondrial potential.Results The histology of rat spleen was affected after sulfur mustard intoxication,as evidenced by apoptosis of a part of lymphocytes.Protein and mRNA expressions of caspase-3 were increased significantly in the spleens of intoxicated rats as compared with that in control group.DNA ladder and 'sub-G1' peak of lymphocytes which were treated with sulfur mustard in vitro were partially improved by Ac-DEVD-CHO(the specific inhibitor of caspase-3).In addition,mitochondrial potential decreased in a time-dependent manner in the lymphocytes intoxicated by sulfur mustard in vitro compared with that in the control group.Conclusions The spleen is injured in the rat which is intoxicated by sulfur mustard.Lymphocyte apoptosis is one of the mechanisms splenic injury.Caspase-3 may be involved in the process of lymphocyte apoptosis induced by sulfur mustard.
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Objective To study the toxic effects of rotenone on substantia nigra of rats. Methods Rotenone was given subcutaneously once a day during 28 days. Substantia nigra was dissected. Morphology of dopamine neuron, synapse and myelin sheath were observed. SOD and GSH-Px activity were assayed; MDA and GSH contents were measured. Results Autonomic activities of rats decreased, similar to Parkinson's Symptoms. Morphology of dopamine neuron changed, synapse structures were abnormal, synapse vesicals increased and myelin sheath degenerated. MDA content increased (P
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Objective The aim of present study was to explore the effects of plateau hypoxia on the cyanide ion metabolism and correlative toxicant mechanism.Methods 12 adult rabbits and 72 male SD rats were randomly divided into two groups separately:plain control group with NaCN intoxication and plateau NaCN intoxicant group.2mg/kg NaCN was subcutaneously injected into the back of rabbits,the femoral vein blood was then collected at different designated time points for the measurement of cyanide,hemoglobin and ferrihemoglobin concentrations.Meanwhile 3.6 mg/kg NaCN was subcutaneously injected into the back of rats,the cardiac blood and the hepatic tissue were then collected at the different designated time points for the determination of cyanide ion,cytochrome oxidase activities and for the detection of pathologic changes of hepatic tissue.Results Under the condition of plain and plateau environments,the pharmacokinetics of rabbits induced by NaCN injection was characterized by one-compartment model.The blood cyanide concentration of rats in both plain and plateau groups reached peak value at 30min,and the activity of cytochrome oxidase decreased.Furthermore,the pathologic diagnosis of rats hepatic tissue suggested that liver injury induced by NaCN intoxication at high altitude was more serious than in plain intoxicant.Conclusion Hypoxia could markedly disturb the metabolic process of NaCN in vivo,aggravate the inhibition of cytochrome oxidase activity and lead to serious pathologic injury.
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Objective To investigate the effects of sodium cyanide(NaCN) and /or acute hypobaric hypoxia on the contents of monoamine neurotransmitters in rats' brain.Methods 128 adult male SD rats were divided into normoxic group and acute hypoxia group with 64 animals for each group.An artificial hypobaric hypoxia chamber was used to simulate a 4 000m altitude situation.The acute hypoxic exposure models were established by exposing rats to the hypobaric chamber for 3 days.All the rats were then injected intra-peritoneally with NaCN in a dosage of 3.6mg/kg at sea level and at simulated high altitude at 0,0.5,2 and 6h time points.The rats were sacrificed and the brains were isolated.The brain tissues of hippocampus and striatum corpora were then dissected on ice.Proteins of the brain tissue were extracted by centrifugation.Contents of dopamine(DA),epinephrine(NE) and 5-hydroxytryptamine(5-HT) in the brain tissues were analyzed by HPLC.Results NaCN intoxication did not affect the contents of DA,NE and 5-HT at 0.5h,2h and 6h in the selected brain tissues of the normoxic group.Compared with non-intoxication group,however,NaCN intoxication for 2h or 6h significantly decreased the levels of NE and 5-HT in the hippocampus tissues and the contents of DA,NE and 5-HT in striatum corpora in acute hypobaric hypoxia group.The contents of DA,NE and 5-HT in striatum corpora and the contents of NE and 5-HT in acute hypoxia group were significantly decreased compared with that in normoxic group(P
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Objective To investigate the toxic effects of rotenone on dopamine transporter in the substantia nigra of the rat. Methods Rats (male) were divided into normal control group, vehicle control group and rotenone experimental group(1.0mg/kg and 1.5mg/kg). The animals were subcutaneously administrated with the vehicle or rotenone in different dosage once a day for 28 days. One day after last injection, the brain was dissected and the substantia nigra was harvested. Protein expressions of tyrosine hydroxylase and dopamine transporter were determined with the methods of immunohistochemistry and Western blot. The mRNA expressions of dopamine transporter and dopamine receptor were detected with RT-PCR respectively. The activity of Na+-K+-ATPase was assayed biochemically. Results In the experimental groups, both the immune positive neurons of tyrosine hydroxylase and the expression of its protein were significantly decreased in the substantia nigra of the rats after rotenone treatment. The number of dopamine transporter antibody-immune positive neurons were significantly increased in the rats exposed to rotenone. Furthermore, protein and mRNA expressions of dopamine transporter in the experimental group were also obviously up-regulated compared with the normal control group. A decreased activity of Na+-K+-ATPase was observed in the substantia nigra of rats in the rotenone experimental group. In addition, the mRNA expression of D2R was also increased in contrast with that in the control group. Conclusions Rotenone is toxic to dopamine neurons in the substantia nigra of rats. Dysfunction of dopamine transporter may be involved in the mechanism of rotenone toxicity to dopamine neurons.