A Preliminary Study On Early Effect Biomarkers Of Neurotoxicity Induced By Acrylamide

Acrylamide (ACR) is a kind of important chemical raw materials that is used primarily to produce polyacrylamides(PAM) whose demand is considered huge. Therefore the demand for ACR continues to increase. Unfortunately, ACR is recognized as a kind of nerve poison. Its products are mainly solution so that air ACR concentrations have a great decrease. But ACR is so easily absorbed into the skin that the neurotoxic effects are more concealment and complexity. In recent decades, ACR caused many occupational poisonings and ACR poisoning was recognized occupational disease by our state. But no biological exposure limit and no specific biomarker have not been found. According to former research products, serum nse, calpain, oxidation-antioxidation levels in ACR poisoning rats had changed obviously. For this reason, we could screen out some early effect biomarkers from NSE、calpain、 GSH、GSH-Px、SOD and MDA so that we send out warning alarm to protect health of workers before poisoning.Objective1To explore the influence of Serum NSE, calpain, oxidation-antioxidation levels by exposure to ACR.2Some early effect biomarkers were screened out.3By optimizing a GC-ECD method for determination of ACR and verifying personal sampling method of ACR, the external exposure level of ACR was accurately reflected. Methods1To optimize a GC-ECD method for determination of ACR and verify personal sampling method of ACR.2The survey was conducted in subjects with a questionnaire. The subjects were divided into the exposed group and controls.3The sampling strategy and analysis of samples(1) The sampling strategy:The air samples were taken by personal sampling using silica gel tubes. The skin samples were taken by tampon with pure water and hollow board. The blood samples were taken by evacuated tubes.(2) Analysis of samples:Air ACR concentration and dermal contamination were detected by GC-ECD. Serum NSE was detected by ECLIA. The activity of calpain in serum was determined by fluorescence method. GSH-Px, GSH, SOD, and MDA serum levels were determined with commercial oxidation-antioxidation assay kits.4Statistical analyses:Statistical analyses were carried out with the PASW Statistics18.0for Windows. Serum NSE, calpain, oxidation-antioxidation levels in subjects were evaluated with the single factor analysis by exposure to ACR. A simple correlation analysis was analysized between exposure dose and NSE, calpain, oxidation-antioxidation levels. The impact of occupational correlation factor and personal basic condition on NSE, calpain, oxidation-antioxidation levels was analysized by One-way ANOVA. Multivariate linear regression analysis on NSE, calpain, oxidation-antioxidation levels.Results1Chromatographic condition optimization and method verificationThe treated samples were detected by capillary column gas chromatography with ECD at following chromatographic condition:injector temperature240℃, column temperature220℃, detector temperature250℃, split ratio1:20, column flow rate3.0ml/min, injection volume2.0μ1. The linear range was0-2.0μg/ml, the detection limit was1.4×10-5μg/ml(S/N=3), the retention time was1.633min. The recovery rate, precision, elution rate, desorption efficiency and collection efficiency accorded with our National Criterion.2Serum NSE, calpain, oxidation-antioxidation levels in subjects were evaluated with the single factor analysis by exposure to ACR. NSE, calpain, SOD and MDA levels in the exposed group were significantly higher than the control group (P<0.05). Calpain level in the exposed group was significantly lower than the control group.3Factors influenced serum NSE, calpain levels in the exposed group(1) A simple correlation analysis between exposure dose and NSE, calpain levels Air ACR concentration was positively correlated with NSE level (r=0.635, P<0.05) and negatively correlated with calpain level (r=-0.214, P<0.05). Dermal ACR contamination was positively correlated with NSE level (r=0.669, P<0.05) and negatively correlated with calpain level (r=-0.231, P<0.05).(2) The impact of occupational correlation factor on NSE, calpain levels through One-way ANOVANSE level was significantly influenced by air ACR concentration, dermal ACR contamination and wearing gloves (P<0.05). Calpain level was significantly influenced by air ACR concentration, dermal ACR contamination and length of exposure (P<0.05).(3) The impact of personal basic condition on NSE, calpain levels through One-way ANOVA Calpain level was significantly influenced by age, education level (P<0.05).(4) Multivariate linear regression analysis on NSE, calpain levels①Multivariate linear regression analysis on NSE level NSE level was significantly influenced by dermal ACR contamination, air ACR concentration, gender, smoking, wearing masks and wearing gloves. But dermal ACR contamination has more influence on NSE level (The standard regression coefficient was relatively high.)②Multivariate linear regression analysis on calpain level Calpain level was significantly influenced by age, dermal ACR contamination, gender, smoking. But age has more influence on NSE level (The standard regression coefficient was relatively high.)4Factors influenced oxidation-antioxidation levels in the exposed group(1) A simple correlation analysis between exposure dose and oxidation-antioxidation levelsAir ACR concentration was positively correlated with GSH-Px, MDA levels (P<0.05). Dermal ACR contamination was positively correlated with MDA level (P<0.05).(2) The impact of occupational correlation factor on oxidation-antioxidation levels through One-way ANOVAGSH-Px level was significantly influenced by air ACR concentration and wearing gloves (P<0.05). GSH level was significantly influenced by air ACR concentration (P<0.05). SOD level was significantly influenced by length of exposure (P<0.05). MDA level was significantly influenced by air ACR concentration, dermal ACR contamination and wearing gloves (P<0.05).(3) The impact of personal basic condition on oxidation-antioxidation levels through One-way ANOVAGSH-Px level was significantly influenced by age, taking fried food and drinking green tea (P<0.05). GSH level was significantly influenced by gender (P<0.05). SOD level was significantly influenced by age, education level (P<0.05).(4) Multivariate linear regression analysis on oxidation-antioxidation levels①Multivariate linear regression analysis on GSH-Px level GSH-Px level was significantly influenced by wearing gloves and taking fried food. But wearing gloves has more influence on GSH-Px level (The standard regression coefficient was relatively high.).②Multivariate linear regression analysis on GSH level GSH level was only significantly influenced by air ACR concentration.③Multivariate linear regression analysis on SOD level SOD level was only significantly influenced by age. ④Multivariate linear regression analysis on MDA level MDA level was significantly influenced by dermal ACR contamination, wearing gloves and wearing masks. But dermal ACR contamination has more influence on MDA level (The standard regression coefficient was relatively high.)Conclusion1NSE, calpain, SOD and MDA levels gone up by exposed to ACR. Calpain level was decreased by exposed to ACR.2Dermal ACR contamination induced changes in the levels of serum NSE, MDA. Workers should be protected from dermal ACR contamination in working time.3We could establish a biomarkers group so that some warning alarms will be sent out to protect health of workers before poisoning. In the group, serum NSE was the center of the biomarker group and serum GSH-Px, MDA levels were supplement.4This study optimize a GC-ECD method for determination of ACR. This method was fast, sensitive and accurate, and can be applicable to quick and accurate determination of ACR in large batch of air samples from workplace. By verifying personal sampling method of ACR, the external exposure level of ACR was accurately reflected.