Chloride Transport across Syncytiotrophoblast Microvillous Membrane of First Trimester Human Placenta

Na(+)-K(+)-ATPase is distributed to microvillous and basal membrane of the syncytiotrophoblast in human placenta.

Despite its importance for placental function, syncytiotrophoblast Na(+)-K(+)-ATPase has not been studied in detail. We purified syncytiotrophoblast microvillous (MVM) and basal (BM) membranes from full-term human placenta. Western blotting with isoform-specific antibodies demonstrated the presence of the alpha(1)-subunit, but not the alpha(2)- or alpha(3)-subunits, in MVM and BM. Relative dens...

Microvillous membrane potential ( E m) in villi from first trimester human placenta: comparison to E m at term.

The microvillous membrane (MVM) potential ( E m) of first trimester human placental villi was measured and compared with that in villi from term human placentas. The median E m in first trimester villi (-28 mV) was significantly more negative than that at term (-21 mV; P < 0.001). The median E m measured in villi from early ( weeks 6-11) first trimester (-32 mV) was significantly more negative ...

Glucose transporter isoform 4 is expressed in the syncytiotrophoblast of first trimester human placenta.

BACKGROUND Placental glucose transport mechanisms in early pregnancy are poorly understood. The aims of this study were to investigate the expression of glucose transporter (GLUT) isoforms 1, 3 and 4 in first trimester villous tissue, to assess the effects of insulin on glucose uptake and compare them with term. METHODS The expression of GLUT isoforms was investigated using immunohistochemist...

Characteristics of glucose transport across the microvillous membranes of human term placenta.

Transport characteristics of D-glucose were studied in the microvillous vesicles isolated from the human term placenta. Transport occurred by selective and rapid facilitated diffusion system which was inhibitable by phloretin and HgCl2. The transport was dependent on a transmembrane. Na+-gradient indicating a "secondary active transport" system operating. The transport influx was saturable and ...

Placenta Percreta Resulting in Incomplete Spontaneous Abortion in First Trimester