Effects of benzo[a]pyrene on autonomic nervous system of coke oven workers.

Objectives are to investigate the effects of benzo[a]pyrene (B[a]P) on the autonomic nervous system of coke oven workers. One hundred eighty-four coke oven workers were divided into 3 groups according to their working sites (coke oven bottom group, coke oven side group and coke oven top group), and 93 referents were recruited. B[a]P monitored by air sampling pumps as well as urinary 1-hydroxypyrene (1-OH-Py) was determined by high performance liquid chromatograph with a fluorescence detector (HPLC-FD). The autonomic nervous system (ANS) function was determined by 4 tests: Valsalva Manoeuvre heart rate variation (HR-V), variation of heart rate when breathing deeply (HR-DB), variation of heart rate when instantly standing up (HR-IS, including RR30:15 and RRmax:min) and variation of blood pressure when instantly standing up (BP-IS). The B[a]P mean concentrations in coke oven bottom, coke oven side and coke oven top were 19, 185 and 1,623 ng/m(3), respectively. The levels of urinary 1-OH-Py were markedly higher in the 3 exposed groups than that in the referent group (p<0.01). No significant difference was found in each group between smokers and non-smokers (p>0.05). Compared with referents, HR-V decreased significantly in coke oven workers (p<0.01), representing modulation of parasympathetic nervous function. However, no statistical differences were found in HR-DB, RR30:15, RRmax:min and BP-IS between the exposed groups and the control group (p>0.05). HR-V decreased with the increment of 1-OH-Py (p<0.05), and results of multiple linear stepwise regression demonstrated that external exposure level and duration of education entered the HR-V model; age was a significant factor of HR-DB and RRmax:min, but no variable was involved in RR30:15 and BP-IS regression. Benzo[a]pyrene affects the autonomic nervous function of coke oven workers mainly by down-regulating the parasympathetic nervous function.

[Relationship between aryl hydrocarbon receptor G1661A gene polymorphism and level of urinary 1-hydroxypyrene of coke oven workers].

OBJECTIVE: To study the relationship between polymorphism of aryl hydrocarbon receptor (AhR) gene in G1661A and the level of urinary 1-hydroxypyrene among coke oven workers. METHODS: 295 male subjects were studied, including 214 workers working in coke oven plant and 81 controls working in raw material plant who were not generally exposed to polycyclic aromatic hydrocarbons occupationally. General in-formation of subjects were collected in a specific questionnaire including age, smoking and drinking habits, the history of occupation and so on. The AhR genotypes were detected by allele specific amplification (ASA), and the levels of urinary 1-hydroxypyrene were measured by high performance liquid chromatography with a fluorescence detector. RESULTS: The frequencies of G/G, G/A and A/A genotype were 52.8% (113/214), 27.6% (59/214) and 19.6% (42/214) in exposed group and 67.9% (55/81), 19.8% (16/81) and 12.3% (10/81) in control group, respectively. No significant difference was found in three genotypes between the exposed and control group. Allele frequencies of G and A were 66.6% (285/428) and 33.4% (143/428) in exposed group and 77.8% (126/162) and 22.2% (36/162) in control group, and no statistical differences were found in allele frequency between exposed and control group. After the length of service and external exposure orders in general linear model were adjusted, results of covariance analysis showed that logarithmic transformed urinary 1-hydroxypyrene levels were (3.62 +/- 0.12), (3.43 +/- 0.12) and (3.44 +/- 0.08) micromol/mol Cr in individuals with A/A, G/A and G/G, respectively. The logarithmic transformed urinary 1-hydroxypyrene levels were (3.24 +/- 0.09) and (3.43 +/- 0.10) micromol/mol Cr in individuals with allele of G and A. No statistical differences were found in level of 1-hydroxypyrene among A/A, G/A and G/G genotype individuals, and between allele G and allele A after external exposure orders and length of service were adjusted. CONCLUSION: The polymorphism of aryl hydrocarbon receptor G1661A has no significant impact on levels of urinary 1-hydroxypyrene.

[Influence of benzo[a]pyrene on learning and memory and content of amino acid neurotransmitters in hippocampus of rats].

OBJECTIVE: To study the effects of benzo[a]pyrene (B[a]P) on capability of learning and memory and the content of amino acid neurotransmitters in hippocampus of rats. METHODS: Thirty-two healthy, male SD rats were randomly divided into 4 groups according to their weights after intubated into ventricles: the solvent control group, 2.5, 5.0 and 10.0 mmol/L groups. 10 microl of B[a]P olive oil solutions, of different concentrations 2.5, 5.0 and 10.0 mmol/L, were injected into rats' lateral ventricles, respectively. Rats in the solvent control group were injected into the same volume of olive oil as that in B[a]P group. Rats' capability of learning and memory was tested by Morris water maze. The content of amino acid neurotransmitters in rats' hippocampus were determined by high performance liquid chromatogram with a fluorescence detector. RESULTS: Compared with the controls, the performances of learning and memory of rats decreased significantly in B[a]P treated groups (P<0.01). Levels of glutamate (Glu) were lower significantly in treated groups than that in controls (P<0.01). No significant differences were found in contents of aspartic acid (Asp), glycine (Gly) and aminobutyric acid (GABA) among the four groups. CONCLUSION: B[a]P can damage rats' spatial learning and memory, and which could be related to decreased contents of excitatory amino acids in hippocampus.

[Relationship between lipid peroxidation in blood and neurobehavioral function changes in coke oven workers].

OBJECTIVE: To explore the coincidence of lipid peroxidation and neurobehavioral function changes in coke oven workers. METHODS: One hundred and thirty-four coke oven workers were divided into three groups: 35 in the oven-bottom group, 49 in the oven-side group and 50 in oven-top group. WHO recommended NCTB was performed on coke oven workers and 36 controls from material conservation department; The contents of total superoxide dismutases (T-SOD), glutathione (GSH) and malondialdehyde (MDA) in blood were determined by test kits. RESULTS: Compared with the controls, the coke oven workers showed lower levels of T-SOD and GSH (P < 0.01), significantly higher MDA levels in blood (P < 0.01), higher score on negative mood state, lower scores on positive mood state, and poorer performance in NCTB test (P < 0.05). Further analysis revealed that there was a weak positive correlation between neurobehavioral function changes and the level of lipid peroxidation with a coefficient lower than 0.25. CONCLUSION: The level of lipid peroxidation in coke oven workers' blood increased and coincided with neurobehavioral function impairment.