BACKGROUND: Benzo[a]pyrene injures central and peripheral nerves at a certain degree. The study is at an initial phase concerning to the neurotoxicity of benzo[a]pyrene allied with other toxic objects.OBJECTIVE: Molecular biological technique integrated with neuron culture were applied in the study of benzo[a]pyrene and lead applied separately or in combination on neurotoxicity and nuclear DNA damage in vitro.DESIGN: Repeated measure.SETTING: Teaching-Research Room of Labor and Hygiene of Chongqing Medical University and Laboratory of Thermobiology and Molecular Toxicology of Occupation Medical Institute of Tongji Medical College of Huazhong University of Science and Technology.MATERIALS: The experiment was performed in Laboratory of Thermobiology and Molecular Toxicology of Occupation Medical Institute of Tongji Medical College ofHuazhong University of Science and Technology from June to September 2003. Ten SD rats of 8-day old were employed and their brain tissues were prepared as primary cell culture object, which were divided into 10 culture groups, 5 culture dishes in each group. The managements were as follows in each group: [1] blank control; [2] solvent control[parallel management with equivalent dimethyl sulfoxide (DMSO) +liver microsome enzyme]; [3] lead group of low concentration (acetic lead 5 μmol/L) (No. 1 group); [4] lead group of high concentration (acetic lead 50 μmol/L) (No. 2 group); [5] benzo[a]pyrene group of low concentration (benzo[a]pyrene 5 μmol/L + liver microsome enzym) (No. 3 group); [6]benzo[a]pyrene group of high concentration (benzo[a]pyrene 50 μmol/L +liver microsome enzym) (No. 4 group); [7] lead of low concentration +benzo[a]pyrene of low concentration group (No. 5 group); [8] lead of low concentration + benzo[a]pyrene of high concentration group (No. 6 group);[9] lead of high concentration + benzo[a]pyrene of low concentration group (No.7 group); [10] lead of high concentration + benzo[a]pyrene of high concentration group (No. 8 group).METHODS: After stained poisoning for 90 minutes, trypsin digestion method was used for sample collection and trypan blue staining method was applied to assay cell survival rate in each group. Single-cell gel electrophoresis (SCGE) was used to determine the damage of nuclear DNA in each group.MAIN OUTCOME MEASURES: Neuronal survival rate and damage rate of nuclear DNA in poisoning with benzo[a]pyrene and lead either in separation or in combination.RESULTS: [1] Cell survival rates in various groups poisoned with benzo [a]pyrene and lead of two concentrations either in separation or combination were lower than the controls [poisoning group (44.14±4.80)% to(82.40±2.70)%, the controls (88.44±2.53)% to ( 90.12±2.23)%, P ＜ 0.05to 0.01]. [2] Degrees of nuclear DNA damage in single poisoning group with benzo[a]pyrene of high concentration, lead of low concentration + benzo[a]pyrene of high concentration, lead of high concentration + benzo[a]-pyrene of low concentration and lead of high concentration + benzo[a]pyrene of high concentration were higher than the controls [63% (19/30), 87%(26/30), 80% (24/30), 97% (29/30), 13% (4/30), 20% (6/30), P ＜ 0.01].CONCLUSION: Both benzo[a]pyrene and lead present neurotoxicity in vitro and coordinate with each other. The damage of benzo[a]pyrene is worse than lead in neuronal nuclear DNA cultured in vitro.

BACKGROUND: Benzo[a] pyrene(BaP) is kind of polyaromatic hydrocarbon which is a chemical pollutant extensively existing in living and productive environments. It is found overseas that it has neurotoxic effects under certain conditions.OBJECTIVE: To study the neurotoxicity of BaP and its effects on expression of two heat stress proteins(HSPs) HSP70 and HSP90β in brain tissue of mice.DESIGN: Randomized case control study of experimental animals.SETTING: Laboratory of thermobiology and molecular toxicology of a unversity, department of preventive medicine of a university.MATERIALS: The experiment was conducted in the Thermobiology and Molecular Toxicity Laboratory, Tongji Medical College, Huazhong Science and Technology University. Fifty male Kunming mice were randomly divided into 5 groups with each of 10 mice including 3 administrated groups, 1 vehicle group and 1 control group. All mice in 3 exposed groups were intraperitoneally administrated BaP dissolved in corn oil at dose levels of 7.8mg/kg, 3.2 mg/kg and 1.3 mg/kg respectively for four times per week. The mice in vehicle group received an equal volume of com oil and the mice in control group received no additional treatment.METHODS: The signs of neurotoxicity in each group were examined and recorded during the administration. At the end of 8-week administration, the brains were excised to calculate brain tissue organ coefficient. Western blot method was used to assay the HSP70 and HSP90β.MAIN OUTCOME MEASURES: Effects of BaP on HSP70 and HSP90βin brain tissue of mice.Bap exposure groups was much lower than that of control group( P ＜ 0. 01,P ＜ 0. 001 ) while the organ coefficient of high dose group was much of HSP70 was characterized by greatly increased expression in low dose group while the relative expression of HSP90β was increased in middle and high dose groups.CONCLUSION: BaP has certain neurotoxic effects. With the increase of toxic dose, the expression of HSP90β increases which can be used as signal of toxic damage under certain conditions.

Objective To know the air benzo[a]pyrene (B[a]P) pollution level in a coke plant of Chongqing Iron & Steel Group. Methods The concentrations of B[a]P in coke oven operating environment were determined by high performance liquid chromatography (HPLC) in different places of work in Sep. 2008.B[a]P concentration at different distances on the surrounding regions of coke plant and real-time monitoring in every quarter around the different functional areas was conducted. Results The air B[a]P concentration in the coke plant was descending following the order: the top of coke oven, the side of coke oven, the bottom of coke oven. B [a]P concentrations of oven bottom, oven side, oven top showed a gradual increase tendency with the extension of the sampling time (P

Based on the existing situation of preventive medicine in our country,this article gives insights into the problems and the resolves of college preventive medical education in the field of society,colleges,teaching materials,teachers,students and teaching conditions.

OBJECTIVEThe present study aimed to test whether exposure to benzo(a)pyrene [B(a)P] affects spatial learning and short-term memory by modulating the expression of the Gria1 and Grin2a glutamate receptor subunit genes in the hippocampus.

METHODSThirty-six 21-24-day-old, male rats were randomly assigned into high-, medium-, and low-dose toxin exposure groups (6.25, 2.5, and 1 mg/kg, respectively) and a control group, each containing nine rats. The behavioral performance of adult rats exposed to sub-chronic administration of B(a)P was monitored by learning and memory tests (Morris water maze). Real-time PCR assays were used to quantify Gria1 and Grin2a gene expression in the hippocampus.

RESULTSAt medium and high doses, B(a)P impaired spatial learning performance. The crossing-platform-location frequency and the time spent swimming in the platform area, which both relate to short-term memory, were significantly decreased in B(a)P-treated rats compared with controls. The level of Gria1 mRNA increased 2.6-5.9-fold, and the level of Grin2a mRNA increased 10-14.5-fold, with a greater fold increase associated with higher doses of B(a)P.

CONCLUSIONWe demonstrated that sub-chronic administration of B(a)P inhibits spatial learning and short-term memory, and increases Gria1 and Grin2a expression in the hippocampus. This suggests a relationship of B(a)P exposure levels with Gria1 and Grin2a expression and impairment of short-term and spatial memory.

Animals ; Behavior, Animal ; drug effects ; Benzo(a)pyrene ; administration & dosage ; toxicity ; Dose-Response Relationship, Drug ; Drug Administration Schedule ; Gene Expression Regulation ; drug effects ; Hippocampus ; metabolism ; Learning ; drug effects ; Male ; RNA, Messenger ; genetics ; metabolism ; Rats ; Receptors, AMPA ; genetics ; metabolism ; Receptors, N-Methyl-D-Aspartate ; genetics ; metabolism

OBJECTIVETo study the toxicological effects of benzo[a]pyrene(BaP) on mammalian animal's nerve tissue.

METHODS50 Kunming mice were divided into 5 groups at random, the exposed groups(3 dose level groups), the vehicle control group and standard control group. Every group got 10 mice. The exposed groups were treated by intraperitoneal injection with BaP dissolved in vegetable oil at 7.8, 3.2 and 1.3 mg/kg respectively, 4 times/week, for 10 weeks, the vehicle control group were given vegetable oil and the standard control group were not given any treatment. All the mice were anesthetized with 0.02 mol/L pentobarbital and infused with 1.33 mol/L paraformaldehyde dissolved in PBS through heart after 10 weeks. Then the brain, spinal cord and sciatic nerve were removed. Slices of these tissues were made and morphological changes were observed by optical microscope and electron-microscope. Cell appoptosis was examined by TUNEL(TdT-mediated x-dUTP nick end labeling) method.

RESULTSMorphological observations showed tissue injury in BaP exposed groups. There were focal necrosis areas found in the high-dose group. The cell apoptosis rates in 3.2 and 1.3 mg/kg groups were 90.02%-94.22% and 62.45%-77.54% respectively, significantly higher than those of vehicle control group and standard control group(4.60%-5.57%).

CONCLUSIONBaP is neurotoxic. It could damage the nerve tissue as well as induce DNA breaks and cell apoptosis.

Animals ; Apoptosis ; drug effects ; Benzo(a)pyrene ; toxicity ; Brain ; drug effects ; pathology ; Dose-Response Relationship, Drug ; In Situ Nick-End Labeling ; Mice ; Sciatic Nerve ; drug effects ; pathology ; Spinal Cord ; drug effects ; pathology

OBJECTIVE: To investigate the effect of benzo(α)pyrene on the ATPase activity and content of Ca²⁺ in the hippocampus of neonatal SD rats. METHODS: Sixty male and 60 female 4-days-old neonatal SD rats were randomly divided into 5 groups (n=24): a blank control group, a vehicle control group (peanut oil), 3 benzo(α)pyrene groups (0.02, 0.2 and 2 mg/kg, respectively). SD rats were given benzo(α)pyrene (dissolved in peanut oil) by gavage daily from postnatal day 4 (PND4) to PND20. The nerve reflex, the condition of neuro-muscle development and motion function were examined in the period of treatment. The colorimetric technique was used to detect the activity of Ca²⁺-ATPase and Ca²⁺-Mg²⁺-ATPase in hippocampus after the treatment. The concentration of Ca²⁺ of synapse in the hippocampus of rats was detected by fluorescent labeling. RESULTS: The results from the behavior tests showed that duration of surface reflex latency in rats with medium dose of benzo(α)pyrene was longer compared with that in the control group in PND12. The duration of surface reflex latency in rats with high dose of benzo(α) pyrene is longer in PND 14 and PND 16 compared with that in the control group (P<0.05). Compared with the rats in the control group, the activities of Ca²⁺-Mg²⁺-ATPase and Ca²⁺-ATPase in hippocampus in rats with high dose benzo(α) pyrene were significantly decreased, and the degree in the decrease of Ca²⁺-ATPase activity was dose-dependent (P<0.05). The contents of Ca²⁺ in the hippocampus in rats with medium or high dose of benzo(α) pyrene were significantly increased compared with that in the control group (P<0.05), which showed a dose-dependent manner (P<0.05). CONCLUSION Benzo(α)pyrene exposure led to the decrease in ATPase activity as well as Ca²⁺ overload of the synapse in the hippocampal tissue, which in turn results in the nerve damage of newborn SD rats.
Animals ; Benzo(a)pyrene ; toxicity ; Ca(2+) Mg(2+)-ATPase ; metabolism ; Calcium ; metabolism ; Calcium-Transporting ATPases ; metabolism ; Female ; Hippocampus ; enzymology ; Male ; Rats ; Rats, Sprague-Dawley

OBJECTIVE: To investigate the protective effects and the potential mechanisms of vitamin E (VE) on benzo(a)pryene (B[a]P)-induced toxicity in the reproductive system of male rats. 
 METHODS: A total of 60 male Sprague Dawley (SD) rats, weighted 70-90 g, were randomly assigned to 6 groups: a control group, a vehicle group, a B[a]P group (5 mg/kg), a VE (10 mg/kg)+ B[a]P (5 mg/kg) group, a VE (50 mg/kg) + B[a]P (5 mg/kg) group and a VE (100 mg/kg)+B[a]P (5 mg/kg) group (n=10 per group). The rats were treated with B[a]P and/or VE once a day for 30 days via intragastric administration. The sperm quality and the levels of SOD, GSH-Px, 8-OHdG and MDA were detected, respectively. The testicular tissue morphology and DNA damage were observed by HE staining and comet assay.
 RESULTS: The sperm count, the rate of sperm deformation, the content of MDA and 8-OHdG were all significantly increased in single B[a]P-treated group in comparison to the control groups. The activities of SOD and GSH-Px were markedly decreased by B[a]P as compared with the control groups (P<0.05). The injury of testicular tissue in B[a]P-treated rats was remarkably improved after VE treatment. The levels of oxidative stress and DNA damage indicators in the B[a]P-treated group were all attenuated by VE. These protective effects of VE were in a dose-dependent manner (P<0.05).
 CONCLUSION Vitamin E can protect the male SD rats against the B[a]P-induced reproductive toxicity.
Animals ; Benzo(a)pyrene ; toxicity ; DNA Damage ; Male ; Oxidative Stress ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Spermatozoa ; drug effects ; Testis ; drug effects ; pathology ; Vitamin E ; pharmacology