INVESTIGADORES
RAMOS Jorge Guillermo
artículos
Título:
Dissociation in the Control of Cervical Eosinophilic Infiltration and Collagenolysis at the End of Pregnancy or After Pseudopregnancy in Ovariectomized Steroid-Treated Rats
Autor/es:
LUQUE EH; RAMOS JG; RODRIGUEZ HA; MUÑOZ DE TORO M
Revista:
BIOLOGY OF REPRODUCTION
Referencias:
Año: 1996 vol. 55 p. 1206 - 1212
ISSN:
0006-3363
Resumen:
Previous studies have demonstrated that during parturition the
physiological ripening that permits dilation of the cervical canal is
due to a widespread collagenolysis that follows a heavy
polymorphonuclear leukocyte invasion of the uterine cervix. The aim of
this study was to investigate whether there is any association between
the ovarian steroid hormones involved in rat parturition and this
phenomenon. Pregnant or pseudopregnant rats were ovariectomized (OVX)
at Day 9 and then given a hormonal treatment (sufficient to maintain
fetal viability) until Day 23. Cervical biopsies, taken from animals
killed intrapartum or 1 h before expected parturition, were studied for
eosinophilic infiltration and collagen birefringence. Intrapartum or
sham-OVX pregnant rats showed a massive eosinophilic infiltration and a
widespread collagenolysis as indicated by a loss of collagen
birefringence. Ovariectomized pregnant rats treated with estrogen plus
progesterone or with progesterone alone showed neither infiltration nor
collagenolysis. In rats OVX during pseudopregnancy, estrogen given
alone induced a significant infiltration of eosinophils in the cervical
stroma; however, treatment with the combination of estrogen and
progesterone was not able to promote eosinophilic infiltration.
Collagenolysis was absent in all pseudopregnant animals. These results
show that estrogen induced a cervical eosinophilic infiltration in rats
but that when progesterone was added to the estrogen treatment the
infiltration was not present; in addition, none of the steroid hormones
assessed were responsible for the collagenolysis found in the cervical
tissue at term.