Blood cerebrospinal fluid barrier damage of rats induced by lead acetate or nano-lead exposure

Abstract

To investigate the damage of blood-cerebrospinal fluid barrier (BCB) of rats induced by lead and nano-lead exposure in order to provide the basis for mechanism study of lead neurotoxicity. 39 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 were determined by ELISA. Confocal laser scanning microscope was applied to detect ZO-1 and Occludin protein expression in choroid plexus, real time-PCR was used to test the expression of ZO-1 and Occludin mRNA expression. Pathological changes of choroid plexus cells were observed by the electron microscopy. Compared with the control group, the escape latency of rats in lead acetate or nano-lead exposure group were longer and times of across platform were less. The levels of CSF albumin and the CSF albumin index in lead acetate or nano-lead exposed rats were obviously higher, and the fluorescence intensity of ZO-1, Occludin as well as mRNA expressions were lower than those in control group(P<0.05). Compared with lead acetate exposed group, the levels of CSF albumin and the CSF albumin index in nano-lead exposure group were higher. The fluorescence intensity and mRNA expressions of ZO-1, Occludin in nano-lead exposure group were than those in lead acetate group(P<0.05). Electron microscopy revealed that lead acetate or nano-lead exposure could induce shorter microvillus of choroid plexus epithelial cells, mitochondrion destruction and partial disconnection in intracellular junctions between two adjacent epithelial cells. Lead acetate and nano-lead exposed can result in the blood-cerebrospinal fluid barrier damage, which may involve in the process of lead induced neurotoxicity. Meanwhile, nano-lead exposure can induced in more worse damage in terms of blood-results in blood-cerebrospinal fluid barrier function.