Colocalization of dopamine D1 and D2 receptor mRNAs in rat placenta.
Dopamine is present in the human placenta. The major function of dopamine is the inhibition of human placental lactogen (hPL) release from human trophoblastic cells. This effect is mediated by cAMP through dopamine D2 receptors. However, studies on the effects of cAMP in the control of hPL release have yielded conflicting results. The purpose of this study is to explore the distribution of dopamine receptors in the rat placenta. Dopamine D1 and D2 receptor mRNAs were colocalized in the rat placenta by in situ hybridization histochemistry using radiolabeled cRNA probes. Dopamine D1 and D2 receptor mRNAs were detected in large cells of the endometrium of the uterus on day 10 of gestation. On days 12-16 of gestation, hybridization signals were localized mainly in the spongiotrophoblast and giant cells of the junctional zone of the placenta. With the development of the placenta, signals were moving from the junctional zone to the labyrinth zone. Pit-1 mRNA was detected in the placental lactotrophs and was also colocalized in neighboring placental sections. Our results clearly showed that dopamine D1 and D2 receptor mRNAs were coexpressed in the placental lactotrophs that express Pit-1 mRNA.
Kim
M O
MO
Department of Anatomy, College of Medicine, Gyeongsang National University, Chinju, Korea.
Kim
J H
JH
Choi
W S
WS
Lee
B H
BH
Cho
G J
GJ
Roh
S M
SM
Lee
B J
BJ
Kang
S G
SG
Kim
C H
CH
Baik
S H
SH
D000818:Animals; D001921:Brain / Q000166:cytology; D004268:DNA-Binding Proteins / Q000235:genetics; D004298:Dopamine / Q000502:physiology; D004717:Endometrium / Q000166:cytology; D005260:Female; D015870:Gene Expression / Q000235:genetics; D005865:Gestational Age; D017403:In Situ Hybridization; D016376:Oligonucleotides, Antisense / Q000235:genetics; D010920:Placenta / Q000166:cytology*; D011247:Pregnancy; D015347:RNA Probes / Q000235:genetics; D012333:RNA, Messenger / Q000032:analysis*; D051381:Rats; D017207:Rats, Sprague-Dawley; D017447:Receptors, Dopamine D1 / Q000235:genetics*; D017448:Receptors, Dopamine D2 / Q000235:genetics*; D050817:Transcription Factor Pit-1; D014157:Transcription Factors / Q000235:genetics
D004268:DNA-Binding Proteins; D016376:Oligonucleotides, Antisense; C494186:Pou1f1 protein, rat; D015347:RNA Probes; D012333:RNA, Messenger; D017447:Receptors, Dopamine D1; D017448:Receptors, Dopamine D2; D050817:Transcription Factor Pit-1; D014157:Transcription Factors; D004298:Dopamine