title: [Effects of low level manganese exposure on the serum neuroendocrine hormones in the welders].
abstract: OBJECTIVE
  To study the effects of low level manganese (Mn) exposure on the serum neuroendocrine hormones levels of the welders.
  
  
  METHODS
  The exposure group consisted of 41 male welders, 40 male workers without exposing to harmful agents served as controls. The serum contents of prolactin (PRL), luteinizing hormone (LH), follicle stimulating hormone (FSH), testosterone (TST) and thyroid stimulating hormone (TSH) of 81 subjects were detected by chemiluminescence immunoassay.
  
  
  RESULTS
  The geometric mean value of airborne Mn concentrations was 0.03 mg/m(3) (0.003 - 0.519 mg/m(3)) in the welding circumstances. The levels of Mn in red blood cells (RBCs) and urinary Mn of the exposure group were significantly higher than those of control group (P < 0.01). The contents of serum LH and TSH of the exposure group were 2.89 ± 0.69 mIU/ml and 1.45 ± 0.56 uIU/ml, which were significantly lower than those (3.82 ± 1.61 mIU/ml and 2.19 ± 1.28 µIU/ml) of control group (P < 0.01). The serum contents of LH, FSH and TSH of the group exposed to Mn for < 5 years were significantly lower than those of the control group, The serum TST level of the group exposed to Mn for < 5 years was significantly higher than those of the control group and group exposed to Mn for 5 ∼ years, the serum FSH level of the group exposed to Mn for < 5 years was significantly lower than that of the group exposed to Mn for 10 years (P < 0.05 or P < 0.01). The serum contents of LH and TSH of the group exposed to Mn for 5 ∼ years were significantly lower than those of the control group (P < 0.05 or P < 0.01). The serum contents of PRL, LH and TSH of the group exposed to Mn for 10 years were significantly lower than those of the control group (P < 0.05). There was negative correlation between blood (RBC) Mn and urinary Mn (r = -0.310, P < 0.05), also there was negative correlation between serum PRL and serum TST (r = -0.409, P < 0.01), the positive correlation between serum LH and serum FSH was observed (r = 0.361, P < 0.05).
  
  
  CONCLUSIONS
  The results of present study showed that the long exposure to low level of Mn may decrease the levels of serum PRL, LH and TSH in workers occupationally exposed to Mn, which can influence the metabolism of neuroendocrine hormones to certain extent.
authors.affiliation: Department of Health Toxicology, Guangxi Medical University, Nanning 530021, China.
authors.forename: Chan
authors.initials: C
authors.lastname: Wang
authors.forename: Ji-pei
authors.initials: JP
authors.lastname: Lu
authors.forename: Yue-ming
authors.initials: YM
authors.lastname: Jiang
authors.forename: Nan-hua
authors.initials: NH
authors.lastname: Ma
authors.forename: Wei-ping
authors.initials: WP
authors.lastname: Qin
authors.forename: Hai-lan
authors.initials: HL
authors.lastname: Luo
authors.forename: Yan-ni
authors.initials: YN
authors.lastname: Huang
authors.forename: Hai-bin
authors.initials: HB
authors.lastname: Chen
mesh_terms: D000328:Adult; D000395:Air Pollutants, Occupational; D005640:Follicle Stimulating Hormone / Q000097:blood; D006801:Humans; D007986:Luteinizing Hormone / Q000097:blood*; D008297:Male; D008345:Manganese; D016273:Occupational Exposure; D011388:Prolactin / Q000097:blood*; D013739:Testosterone / Q000097:blood; D013972:Thyrotropin / Q000097:blood*; D014896:Welding
chemical_list: D000395:Air Pollutants, Occupational; D013739:Testosterone; D008345:Manganese; D011388:Prolactin; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone; D013972:Thyrotropin