title: [Influence of chronic lead exposure in rats during the developmental stage on expression of leptin in plasma, cerebrospinal fluid, and hippocampus].
abstract: OBJECTIVE
  To investigate the influence of lead exposure in rats during the developmental stage on the expression of leptin in plasma, cerebrospinal fluid, and hippocampus, as well as investigating whether leptin is associated with the mechanism of cognitive impairment induced by lead exposure.
  
  
  METHODS
  The rat model of cognitive impairment after chronic lead exposure was established by adding lead acetate into drinking water. According to the concentration of lead acetate in drinking water, the rats were divided into control (0 ppm), low-lead (50 ppm), medium-lead (200 ppm), and high-lead groups (1 000 ppm), with 16 rats in each group. Atomic absorption spectrometry was used to measure the content of lead in the plasma, cerebrospinal fluid and hippocampus. ELISA was used to measure the level of leptin in the plasma and cerebrospinal fluid. Immunohistochemistry was used to observe the distribution of leptin protein in the hippocampus. Western blot was used for relative quantification of leptin proteins in the hippocampus.
  
  
  RESULTS
  Compared with the control group, the lead exposure groups showed significant increases in the content of lead in blood, cerebrospinal fluid, and hippocampus (P<0.01), as well as significant reductions in the levels of leptin in plasma and cerebrospinal fluid (P<0.05). The results of immunohistochemical staining showed that leptin was mainly distributed in the cytoplasm of pyramidal neurons in the hippocampal CA region. The results of Western blot showed that compared with the control group, the three lead exposure groups showed a slight increase in the protein expression of leptin in the hippocampus (P>0.05).
  
  
  CONCLUSIONS
  Lead exposure can reduce the levels of leptin in plasma and cerebrospinal fluid in rats, which may be associated with the mechanism of cognitive impairment induced by lead exposure.
authors.affiliation: Department of Laboratory, West China Second University Hospital, Sichuan University, Chengdu 610041, China. yangh00@126.com.
authors.forename: Xue-Mei
authors.initials: XM
authors.lastname: Shi
authors.forename: Ya-Wen
authors.initials: YW
authors.lastname: Fu
authors.forename: Lai-Rong
authors.initials: LR
authors.lastname: Huang
authors.forename: Hui
authors.initials: H
authors.lastname: Yang
mesh_terms: D000818:Animals; D017209:Apoptosis / Q000187:drug effects; D003071:Cognition / Q000187:drug effects*; D005260:Female; D006624:Hippocampus / Q000737:chemistry / Q000187:drug effects* / Q000473:pathology; D007854:Lead / Q000097:blood / Q000633:toxicity*; D020738:Leptin / Q000032:analysis* / Q000097:blood / Q000134:cerebrospinal fluid; D008297:Male; D051381:Rats; D017207:Rats, Sprague-Dawley
chemical_list: D020738:Leptin; D007854:Lead