[Evidence that periplacentary leukocytes subpopulations of term pregnancy have functional properties associated with labor induction].
BACKGROUND
The rise of cholagenolitic activity in fetal membranes, associated to premature rupture, have been related to abnormal activity of the extracellular matrix metalloproteinases discharged to the extracellular space as inactive enzymes that have to be activated to selectively degrade its components.


OBJECTIVE
To analyze the functional properties of leukocytes subpopulations coming from the placental circulation.


METHODS
Biomedical experimental study in which placental and outlying blood leukocytes were cultivated during 96 hours, from women with pregnancy to term without labor. Leukocytes subpopulations were stained by flow cytometry. Culture media were analyzed with zymography and enzymatic activity profile was evaluated in presence of proteases inhibitors.


RESULTS
Placental leukocytes are composed of T-, NK- and B-lymphocytes, and monocytes; it was documented a progressive increase of inactive MMP-9 secretion (92 kDa), accompanied by an 82 kDa form MMP-9 activation since 48 hours. Enzymatic profile mainly showed metalloproteasas.


CONCLUSIONS
Placental blood leukocytes showed functional capacities different from those that circulate in pregnant women's outlying circulation. Placental leukocytes, mainly T-lymphocytes, are characterized by the specific capacity to secrete and activate MMP-9; an enzyme that participates in fetal membranes degradation. It suggests that in placental surroundings are recruited cells specialized in labor changes induction.
Flores Pliego
Arturo
A
Departamento de especialidades médicas, Instituto Nacional de Perinatología Isidro Espinosa de los Reyes, Lomas de Virreyes, México.
Beltrán Montoya
Jorge
J
Gómez López
Nardhy
N
Vadillo Ortega
Felipe
F
D002478:Cells, Cultured; D005260:Female; D006801:Humans; D007745:Labor Onset / Q000097:blood* / Q000502:physiology*; D007962:Leukocytes / Q000502:physiology*; D010920:Placenta / Q000098:blood supply; D011247:Pregnancy; D047929:Term Birth