Reversing the negative effects of co-inhaled manganese and iron on dopamine levels and prolactin production in the rat hypothalamus-pituitary axis  

作　　者：Chae Kwan Lee 

机构地区：[1]Institute of Environmental and Occupational Medicine,Department of Occupational & Environmental Medicine,Busan Paik Hospital,Inje University

出　　处：《Neural Regeneration Research》2010年第7期525-530,共6页中国神经再生研究（英文版）

摘　　要：BACKGROUND： Manganese （Mn） and iron （Fe） are the primary elements of welding rods. Mn has been shown to increase prolactin （PRL） production by decreasing dopamine （DA） levels in the hypothalamus. However, Fe increases DA levels and decreases PRL levels. The toxic mechanism of Mn and Fe co-inhalation-induced regulation of the hypothalamic-hypophyseal-pituitary axis remains unclear. OBJECTIVE： To evaluate the effects of co-inhaled Mn and Fe on hypothalamic DA levels and pituitary PRL production, to investigate whether these changes are reversible, and to determine the role of co-inhaled Mn and Fe. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment based on inhalation toxicity via whole-body exposure was performed. Hypothalamic DA levels, serum PRL, and PRL and PiN mRNA levels were analyzed at the Institute of Environmental and Occupational Medicine, Inje University, Busan, Korea, from August 2007 to May 2009. MATERIALS： MnSO4 and FeSO4 were purchased from Sigma-Aldrich, St. Louis, MO, USA. High-performance liquid chromatography （HPLC） using an electrochemical detector （ECD） was purchased from Waters Corporation, Milford, MA, USA. mRNA Capture Kit and reverse transcription-polymerase chain reaction （RT-PCR） kit were obtained from Roche Molecular Biochemicals, Mannheim, Germany and Perkin-Elmer, Wellesley, MA, USA, respectively. Rat PRL enzyme-linked immunosorbent assay kit was purchased from Biocode Hycel, Liege, Belgium. METHODS： Eighty 15-week-old, male, Fischer 344 rats were assigned to two groups： one group treated with Mn and Fe and a control group. Each group was sub-divided into four groups on the basis of treatment period （0- and 13-week treated groups with both chemicals） and recovery periods （4- and 13-week recovery groups following 13-week exposure to both chemicals）. The treatment condition was 6 hours per day, 5 days per week, for the entire body. Mn and Fe co-inhalation concentrations were 1.5 mg/m3 and 3.0 mg/m3, respectively. MAIN OUTBACKGROUND： Manganese （Mn） and iron （Fe） are the primary elements of welding rods. Mn has been shown to increase prolactin （PRL） production by decreasing dopamine （DA） levels in the hypothalamus. However, Fe increases DA levels and decreases PRL levels. The toxic mechanism of Mn and Fe co-inhalation-induced regulation of the hypothalamic-hypophyseal-pituitary axis remains unclear. OBJECTIVE： To evaluate the effects of co-inhaled Mn and Fe on hypothalamic DA levels and pituitary PRL production, to investigate whether these changes are reversible, and to determine the role of co-inhaled Mn and Fe. DESIGN, TIME AND SETTING： A randomized, controlled, animal experiment based on inhalation toxicity via whole-body exposure was performed. Hypothalamic DA levels, serum PRL, and PRL and PiN mRNA levels were analyzed at the Institute of Environmental and Occupational Medicine, Inje University, Busan, Korea, from August 2007 to May 2009. MATERIALS： MnSO4 and FeSO4 were purchased from Sigma-Aldrich, St. Louis, MO, USA. High-performance liquid chromatography （HPLC） using an electrochemical detector （ECD） was purchased from Waters Corporation, Milford, MA, USA. mRNA Capture Kit and reverse transcription-polymerase chain reaction （RT-PCR） kit were obtained from Roche Molecular Biochemicals, Mannheim, Germany and Perkin-Elmer, Wellesley, MA, USA, respectively. Rat PRL enzyme-linked immunosorbent assay kit was purchased from Biocode Hycel, Liege, Belgium. METHODS： Eighty 15-week-old, male, Fischer 344 rats were assigned to two groups： one group treated with Mn and Fe and a control group. Each group was sub-divided into four groups on the basis of treatment period （0- and 13-week treated groups with both chemicals） and recovery periods （4- and 13-week recovery groups following 13-week exposure to both chemicals）. The treatment condition was 6 hours per day, 5 days per week, for the entire body. Mn and Fe co-inhalation concentrations were 1.5 mg/m3 and 3.0 mg/m3, respectively. MAIN OUT

关 键 词：DOPAMINE hypothalamic-hypophyseal-pituitary axis IRON MANGANESE Pit-1 PROLACTIN 

分 类 号：R114[医药卫生—卫生毒理学]