Study Of Blood CSF Barrier Damage Induced By The Lead Acetate And Nano-Lead

Objectives To investigate the differences in terms of blood-cerebrospinal fluid barrier( BCB) damage of rats induced by lead acetate or nano-lead exposure in order to provide the basis for mechanism of lead neurotoxicity.Methods 81 male rats were randomly divided into control group, lead acetate exposed group and nano-lead exposed group. Rats in lead acetate exposed group and nano-lead exposed group were given 20 mg/kg lead acetate or nano-lead by oral gavage and rats in control groups were given the same amount saline for 9 weeks.Morris maze was used to test the learning function;Serum albumin and CSF albumin, IL-4,IFN-γ and CXCL10 were determined by ELISA. Confocal laser scanning microscope was applied to detect ZO-1,Occludin, ICAM-1 protein expression in choroid plexus; real-time PCR was used to test the expression of ZO-1, Occludin, IL-4, IFN-γ, CXCL10 and ICAM-1 m RNA expression;Pathological changes of choroid plexus cells were observed by the electron microscopy;Flow cytometry was used to conunt the CD4 + T lymphocyte number in the blood and CSF.Results 1 The growth and development information of experiments rat: The body weight of rats in three groups didn’t show the significant difference during the exposure. 2Compared with the control group, the escape latency of rats in lead acetate and nano-lead exposure group were longer,and the nano-lead exposure group prolonged 32.89% than the lead acetate(P< 0.05).Times of across platform was less in the lead acetate and nano-lead exposure group than that in the control group and the difference was significant(P<0.05).However,there was no significant difference between nano-lead sulfide lead acetate group. 3 The CSF albumin content in the lead acetate and nano-lead exposure group increased 25.18% and 47.70% than that in the control group, and the nano-lead exposure group increased 17.98% than that of the lead acetate group. Albumin index in two lead groups of CSF were lower than the control group, especially for nano-lead group(P< 0.05);compared with the control group, the contents of IL-4,IFN-γ increased(72.13%, 93.56%)and(54.61%, 43.50%), the contents of CXCL10 decreased(43.11%,53.44%) in the lead acetate group and nano-lead exposure group(P<0.05). The content of IL-4 in nano-lead exposure group was lower than the lead acetate group, the content of IFN-γ was higher205.06% than the lead acetate group(P<0.05). 4 In the control group, the fluore-scence intensity of ZO-1 was continuous and linea. The fluorescence intensity of ZO-1 became weak, distribution showed discontinuity in lead acetate and nano-lead exposure group,especially for nano-lead exposure group rats. The fluorescence intensity of Occludin in the lead acetate group and nano-lead exposure group decrease than that in control group. The fluorescence intensity of Occludin in the nano-lead exposure group reduced compared with the lead acetate group. Compared with the control group, the fluorescence intensity of ICAM-1 increased in the lead acetate group and nano-lead exposure group. 5 Compared with the control group, the m RNA expression of ZO-1, occludin decreased in the lead acetate group and nano-lead exposure group. The ZO-1, occludin m RNA expression of the nano-lead exposure group were higher 59.37%,11.90% than the lead acetate group, and the difference is statistically significant(P<0.05). Compared with the control group, the ICAM-1, IL-4, IFN-γ m RNA expression increased in the lead acetate group and nano-lead exposure group,meanwhile, and the CXCL10 m RNA expression reduced.There was a significant difference between the nano-lead exposure group(P<0.05), the ICAM-1, IL-4and CXCL10 m RNA expres-sion of the nano-lead exposure group increased 31.19%,72.57% and 42.86% respect-tively and the IFN-γ decreased 21.63% than those in the lead acetate group(P<0.05). 6 In the lead acetate group, the proportion of CD4 + T lymphocyte in blood increased as well as the proportion of CD4 + T lymphocyte in CSF in the lead acetate group and nano-lead exposure group(P<0.05). 7 In the lead acetate group and nanolead exposure group, the choroid plexus microvilli were shorter and arranged out of order;The morphology of mitochondrial changed. There were no significant difference between the lead acetate and nano-lead exposure group in terms of microvilla and mitochondrial morphology.Conclusions Lead acetate and nano-lead exposed can decrease learning and memory function, result in the blood-cerebrospinal fluid barrier and immune surveillance function damage, the nano-lead more over.