Effects Of Lead Exposure On Amino Acid Neurotransmitter Levels In Developmental

Objective To study the intervention effects of sodium para-aminosalicylate acid (PAS-Na) on concentrations of Glu, Gln, GABA in serum, cortex and hippocampis of rats induced by lead.Materials and Methods According to indivdual weight, we subdivded all the samples into five groups (10 for each group):the control group, the lead-exposoed group, the low does PAS-Na treatment group (L-PAS), the medium does PAS-Na treatment group (M-PAS) and the high does PAS-Na treatment group (H-PAS). The rats of lead-exposoed group and PAS-Na treatment groups received daily intraperitoneal injection (ip.) with lead acetate (10mg/kg) and the control group with normal saline (NS) for 2 weeks. Then, PAS-Na-treated groups received daily subcutaneous injection with 100mg/kg, 200mg/kg or 300mg/kg PAS-Na, respectively. At the same time, the remaining groups treated with NS for 3 weeks. Morris Water Maze (MWM) was used to detect the ability of learning and memory of each group. At the end of treatment, all rats were enthanasia. Blood samples collected from abdominal aortic; cortex and hippocampus were dissected and kept on the ice. Lead analysis was performed by graphite furnace atomic absorption (GFAAS). Glu, Gln, GABA were determined using a high performance liquid chromatography (HPLC).Results Compared with the control group, MWM showed the escape latency and swimming distance were lengthened in lead-exposure group, but the number of piercings was reduced. In lead-exposed group, the level of lead in blood, cortex and hippocampus was higher than control group, after treating with PAS-Na, lead in whole blood was decreased (P<0.05). Glu, Gln of hippocampus in lead-exposed group were higher than that in control group (P＜0.05). Compared with lead-exposed group, Glu of H-PAS group in serum, L-, M-PAS group in cortex, L-, M-, H-PAS group in hippocampus were increased; Gln of L-, M-, H-PAS group in hippocampus were escalated; GABA of H-PAS group in serum, L-, M-, H-PAS group in hippocampus were decreased (P<0.05).Conclusion Lead can decrease the level of Glu and Gln in hippocampus. Treatment with PAS-Na may result in an reduction of blood lead and an increase of Glu and Gln, and an decrease of GABA in hippocampus. These results suggested that PAS-Na had intervention effects on the changes of amino acid neurotransmitters induced by lead.EFFECTS OF LEAD EXPOSURE ON AMINO ACID NEUROTRANSMITTERS IN CHILDRENObjective To investigate the concentration of glutamate (Glu), glutamine (Gln) and y-aminobutyric acid (GABA) in serum from lead-exposoed children.Materials and Methods A total of 249 children (124boys and 125girls) were enrolled from an elementary school in a lead-zinc mine of Guangxi in this study. A volume of 1ml fasting venous blood was collected from each child with heparin anticoagulant tubes, and immediately vortexed. Serum was obtained by coagulation and centrifugation at 2000r/min for 15 min at 4℃. All samples were stored at-80 ℃ until use. Lead analysis was performed by graphite furnace atomic absorption (GFAAS). Glu, Gln, GABA were determined using a high performance liquid chromatography (HPLC). A number of 11 rice samples were randomely collected and the lead level were detected with GFAAS.Results The mean level of lead in collected rice was 160.3 (45.5-525.9) μg/g. According to the standard level in GB2762-2012, the rate of rice with elevated lead was 18.2%. Blood lead level (BLL)≧100ug/L was defined as lead intoxication. The overall mean BLL (Mean ±sD) was 94.2±46.6μg/L (boys: 94.8±42.7μg/L, girls:93.7±50.4μg/L). The incidence of children lead poisoning was 30.9%(boys:35.5%, girls:26.4%). There was no statistically significant according to sex or age. With age increased, serum Gln was increased (P＜0.05). The level of GABA (740.4±213.0μmol/L) in children with 9-year-old was the lowest among all groups(P<0.05). The content of Glu, Gln, GABA with elevated blood lead level was declined, but the difference has no significance (P>0.05). There was no correlation bewteen lead and Glu, Gln, GABA (P>0.05).Conclusion The lead of children in this lead-zirc ore dictrict remains high. The harmful effects of lead-induced on Glu, Gln, GABA were not observed in serum of children in the current situation.