Characteristics and oxidative stress on rats and traffic policemen of ambient fine particulate matter from Shenyang.

Fine particulate matter (PM2.5) pollution is becoming serious in China. This study aimed to investigate the impact of PM2.5 on DNA damage in Shenyang city. The concentration and composition of PM2.5 in traffic policemen's working sites including fields and indoor offices were obtained. Blood samples of field and office policemen were collected to detect DNA damage by Comet assay. Rats were used to further analyzing the oxidative DNA damage. The average concentration of PM2.5 in exposed group was significantly higher than that in control group. Composition analysis revealed that toxic heavy metal and polycyclic aromatic hydrocarbon substances were main elements of this PM2.5. DNA damage in field policemen was significantly higher than those in non-field group. Moreover, animal studies confirmed the oxidative DNA damage induced by PM2.5. Taken together, high DNA damages are found in the Shenyang traffic policemen and rats exposed to high level of airborne PM2.5.

Effect of GR82334 on the Electric Stimulation-induced Increase of Dopamine Content in Anterior Cingulate Gyrus in Rats / 中国医科大学学报

Objective To investigate the effects of GR82334 caudal veins injection(iv)or intrathecal injection(ith)on the increase of dopamine (DA)content in rats anterior cingulate gyrus(ACG)induced by heavy current stimulation of saphenous nerve(SN). Methods Totally 42 male Wi-star rats were randomly divided into six groups,including control group,sham stimulation group,SN stimulation group,GR82334(ith)group,NS (ith)group,GR82334(iv)group,and NS(iv)group. At the end of the study,rats of different groups were sacrificed,then the right side ACG were collected and weighted. ACG samples were then homogenized with 0.1 mol/L perchloric acid solution. After spinning at 10 000 r/min(4℃)for 20 min,20μL of the supernatant were harvest from each sample. High performance liquid chromatography electrochemical detection was used to mea-sure DA content. Results Heavy current stimulation of SN caused obvious increase of the DA content in ACG. GR82334(iv or ith)antagonized the significant increase of DA content in ACG induced by the stimulating SN. However,GR82334(ith)did not completely antagonized the increase of DA content in ACG induced by electric stimulating SN. Conclusion The results indicated that there is connection between SN and the dopami-nergic nervous system in ACG,and SN afferent nociceptive signals can activate ACG dopaminergic neurons to release DA. Peripheral and central NK-1 receptors are involved in the process of significant increase of DA content in ACG induced by SN afferent signals. However,there are other central paths of SN information input to ACG to induce obvious increases of DA content,in which other neurotransmitters and receptors may be involved.