Plasma membrane and vesicular monoamine transporters in normal endometrium and early pregnancy decidua.
The uterus is innervated by adrenergic sympathetic fibres, and the endometrium has a capability for endogenous monoamine synthesis. Extracellular monoamine levels are regulated primarily through re-uptake by specific membrane-bound transporter proteins dopamine transporter (DAT), norepinephrine transporter (NET) and serotonin transporter (SERT). Intracellular storage of monoamines involves vesicular transporter proteins (VMAT1 and VMAT2). This study explored gene expression of the monoamine transporters in normal endometrium throughout the menstrual cycle and early decidua. In-situ hybridization histochemistry revealed three general classes of expression patterns: (i). epithelial expression of NET mRNA; (ii). increasing stromal expression of VMAT2 mRNA in the proliferative phase; and (iii). increasing epithelial expression of VMAT2 mRNA during the secretory phase. Real time PCR showed low expression levels of NET in all phases of the endometrial cycle and a higher expression of VMAT2 mRNA in the mid-secretory phase. Our results suggest that several monoamine transporters may have menstrual cycle phase-specific functions in endometrial biology by maintaining adequate levels of monoamines. Re-uptake and regulated release of monoamines may also modulate several steps of the reproductive processes such as embryo implantation and decidua formation.
Bottalico
Barbara
B
Department of Obstetrics and Gynecology, Lund University Hospital, 221 85 Lund, Sweden.
Pilka
Radovan
R
Larsson
Irene
I
Casslen
Bertil
B
Marsal
Karel
K
Hansson
Stefan R
SR
D002462:Cell Membrane / Q000378:metabolism; D003656:Decidua / Q000378:metabolism; D010064:Embryo Implantation; D004717:Endometrium / Q000378:metabolism; D005260:Female; D006801:Humans; D008562:Membrane Glycoproteins / Q000235:genetics; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism; D050493:Vesicular Monoamine Transport Proteins
D008562:Membrane Glycoproteins; D012333:RNA, Messenger; D050493:Vesicular Monoamine Transport Proteins