Objective To investigate the potential involvement of DMT1 (IRE) protein in the brain vascular system in vivo during Pb exposure.
Methods Three groups of male Sprague-Dawley rats were exposed to Pb in drinking water, among which two groups were concurrently administered by oral gavage once every other day as the low and high Fe treatment group, respectively, for 6 weeks. At the same time, the group only supplied with high Fe was also set as a reference. The animals were decapitated, then brain capillary-rich fraction was isolate from cerebral cortex. Western blot method was used to identify protein expression, and RT-PCR to detect the change of the mRNA.
Results Pb exposure significantly increased Pb concentrations in cerebral cortex. Low Fe dose significantly reduced the cortex Pb levels, However, high Fe dose increased the cortex Pb levels. Interestingly, changes of DMT1 (IRE) protein in brain capillary-rich fraction were highly related to the Pb level, but those of DMT1 (IRE) mRNA were not significantly different. Moreover, the consistent changes in the levels of p-ERK1/2 or IRP1 with the changes in the levels of DMT1 (IRE).
Conclusion These results suggest that Pb is transported into the brain through DMT1 (IRE), and the ERK MAPK pathway is involved in DMT1 (IRE)-mediated transport regulation in brain vascular system in vivo.

Objective To study the effects of environmental multi-media lead pollution on blood lead and sex hormone levels among lead exposed males engaged in E-waste dismantling, and the correlation between confounding factors and sex hormone levels. Methods An E-waste dismantling area in Taizhou of Zhejiang Province was selected as the research site. One hundred and fifty two samples were collected from the groundwater, soil, rice, corn, chicken, and pork in the dismantling area. The effects of the multi-media lead pollution on the male blood lead and sex hormone levels of FSH, LH, and T, as well as the correlation with confounding factors, were studied. Results The blood lead concentrations in the males aged under 31, from 31 to 45 and from 46 to 60 were 98.55, 100.23, and 101.45μg/L , respectively. Of all the environmental media lead exposures, the groundwater, rice and soil were main contributing factors to the lead accumulation in humans. FSH and LH levels increased with the age while the T levels decreased with the age instead. There was a significant correlation between the FSH and LH levels and wearing masks. Conclusion There was correlation between the FSH, LH, and T levels, and the mean values of lead concentrations in environmental media, and the sex hormone levels were correlated with the confounding factor of wearing masks.

牛磺酸拮抗铅对大鼠海马NOS阳性神经元数目的影响

Objective: To study taurine resist lead impact ability of learning and memory. Methods: Using NADPH - dhistochemistry method to study the quantity change of the rat's NOS positive neuron in hippocampus , the rat in experi-ment sections which are feeded with distinct dosage lead acetate in drinking (0.02, 0.2g/L) and feed contain distinctdosage taurine (5, 10g/kg). Results: Taurine could increase NOS positive neuron quantity obviously in hippocampus ofrat induced lead lesion. Conclusion: Taurine could resist lead impact ability of learning and memory obviously.

慢性染铅大鼠海马脑源性神经营养因子的改变

Objective: To investigate the changes of brain derived neurotrophic factor(BDNF) in hippocampus of chronic lead exposed rats. Methods: Wistar rats were exposed to lead by drinking 0.02%、0.2% lead acetate solution for three months, respectively. Investigate the changes of learning and memory ability by Y-labyrinth experiment, study the changes of BDNF positive neuron in CA1, CA3 and dentate gyrus in hippocampus of rats by immunohistochemistry. Results: BDNF positive neurons distribute everywhere in the hippocampus under normal condition. Compared with the contral group, the number of BDNF positive neurons in the hippocampus subregions were decreased significantly of two different dosage (0.02%, 0.2% ) chronic lead exposed groups( P ＜ 0. 05). Conclusion: These results suggest that the reduction of BDNF positive neuron in hippocampus might be related to the impact of lead on learning and memory.