Effects of manganese exposure on dopamine and prolactin production in rat.
Although manganese (Mn) has been shown to increase prolactin (PRL) by decreasing dopamine (DA) in the hypothalamus, the mechanism of Mn-induced regulation of the hypothalamic-hypophyseal-pituitary axis is unclear. We assessed the effects of inhaled Mn on hypothalamic DA and pituitary PRL production and evaluated the role of pituitary-specific transacting factor 1 (Pit-1), a transacting factor of PRL gene, in Mn-induced changes in PRL secretion in the rat brain. Male rats exposed to Mn for 4 or 13 weeks (1.5 mg/m3, 6 h/day, 5 days/week) showed a progressive and significant decrease in hypothalamic DA, whereas PRL and Pit-1 mRNA levels increased in response to Mn exposure. These results suggest that exposure to Mn decreases hypothalamic DA and promotes the production of PRL in the pituitary and that Pit-1 might be a regulator of DA and PRL.
Kim
Hyeon Yeong
HY
Chemical Safety and Health Research Center, Occupational Safety and Health Research Institute, Yuseong-Gu, Daejeon, Korea.
Lee
Chae Kwan
CK
Lee
Jong Tae
JT
Moon
Chan Seok
CS
Ha
Sung Chang
SC
Kang
Sung Goo
SG
Kim
Dae Hwan
DH
Kim
Hwi Dong
HD
Ahn
Jin Hong
JH
Lee
Sung-Bae
SB
Kang
Min-Gu
MG
D000818:Animals; D015152:Blotting, Northern; D002851:Chromatography, High Pressure Liquid; D004298:Dopamine / Q000032:analysis / Q000378:metabolism*; D007031:Hypothalamus / Q000187:drug effects / Q000378:metabolism; D008297:Male; D017895:Manganese Compounds / Q000008:administration & dosage / Q000494:pharmacology*; D010902:Pituitary Gland / Q000187:drug effects / Q000378:metabolism; D011388:Prolactin / Q000097:blood / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011863:Radioimmunoassay; D051381:Rats; D011916:Rats, Inbred F344; D020133:Reverse Transcriptase Polymerase Chain Reaction; D013431:Sulfates / Q000008:administration & dosage / Q000494:pharmacology*; D013997:Time Factors; D014131:Trace Elements / Q000008:administration & dosage / Q000494:pharmacology; D050817:Transcription Factor Pit-1 / Q000235:genetics / Q000378:metabolism
D017895:Manganese Compounds; D012333:RNA, Messenger; D013431:Sulfates; D014131:Trace Elements; D050817:Transcription Factor Pit-1; D011388:Prolactin; D004298:Dopamine; C039798:manganese sulfate