Monoamine transporters in human endometrium and decidua.
BACKGROUND
Monoamines play important roles in decidualization, implantation, immune modulation and inflammation. Furthermore, monoamines are potent vasoactive mediators that regulate blood flow and capillary permeability. Regulation of the uterine blood flow is important both during menstruation and pregnancy. Adequate monoamine concentrations are essential for a proper implantation and physiological development of pregnancy. Unlike most transmitter substances, monoamines are recycled by monoamine transporters rather than enzymatically inactivated. Their intracellular fate is influenced by their lower affinity for inactivating enzymes than for vesicular transporters located in intracellular vesicles. Thus, cells are capable not only of recapturizing and degrading monoamines, but also of storing and releasing them in a controlled fashion.


METHODS
The general objective of the present review is to summarize the role of the monoamine transporters in the female human reproduction. Since the transporter proteins critically regulate extracellular monoamine concentrations, knowledge of their distribution and cyclic variation is of great importance for a deeper understanding of the contribution of monoaminergic mechanisms in the reproductive process. MEDLINE was searched for relevant publications from 1950 to 2007.


RESULTS
Two families of monoamine transporters, neuronal and extraneuronal monoamine transporters, are present in the human endometrium and deciduas.


CONCLUSIONS
New knowledge about monoamine metabolism in the endometrium during menstruation and pregnancy will increase understanding of infertility problems and may offer new pharmacological approaches to optimize assisted reproduction.
Hansson
Stefan R
SR
Department of Obstetrics and Gynecology, Lund University Hospital, Sweden. stefan.hansson@med.lu.se
Bottalico
Barbara
B
Noskova
Vera
V
Casslén
Bertil
B
D015306:Biogenic Monoamines / Q000378:metabolism* / Q000502:physiology; D003656:Decidua / Q000098:blood supply / Q000378:metabolism*; D010064:Embryo Implantation; D004717:Endometrium / Q000098:blood supply / Q000166:cytology / Q000378:metabolism*; D004847:Epithelial Cells / Q000378:metabolism; D033705:Equilibrative Nucleoside Transport Proteins / Q000378:metabolism / Q000502:physiology; D005260:Female; D006801:Humans; D027701:Organic Cation Transport Proteins / Q000235:genetics / Q000378:metabolism / Q000502:physiology; D010929:Placentation; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism; D012098:Reproduction / Q000502:physiology; D017154:Stromal Cells / Q000378:metabolism; D013379:Substrate Specificity; D050493:Vesicular Monoamine Transport Proteins / Q000378:metabolism / Q000502:physiology*; D000099254:Organic Cation Transporter 3
D015306:Biogenic Monoamines; D033705:Equilibrative Nucleoside Transport Proteins; D027701:Organic Cation Transport Proteins; D012333:RNA, Messenger; D050493:Vesicular Monoamine Transport Proteins; D000099254:Organic Cation Transporter 3; C493452:SLC18A2 protein, human; C495988:SLC29A4 protein, human