INVESTIGADORES
RAMOS Jorge Guillermo
artículos
Título:
Guinea-pig interpubic joint (symphysis pubica) relaxation at parturition: underlying cellular processes that resemble an inflammatory response
Autor/es:
RODRÍGUEZ HA; ORTEGA HH; RAMOS JG; MUÑOZ DE TORO M; LUQUE EH
Revista:
REPRODUCTIVE BIOLOGY AND ENDOCRINOLOGY
Referencias:
Año: 2003 vol. 1 p. 113 - 121
ISSN:
1477-7827
Resumen:
BACKGROUND: At term, cervical ripening in coordination with uterine
contractions becomes a prerequisite for a normal vaginal delivery.
Currently, cervical ripening is considered to occur independently from
uterine contractions. Many evidences suggest that cervical ripening
resembles an inflammatory process. Comparatively little attention has
been paid to the increased flexibility of the pelvic symphysis that
occurs in many species to enable safe delivery. The aim of this study
was to investigate whether the guinea-pig interpubic joint relaxation
process observed during late pregnancy and parturition resembles an
inflammatory process. METHODS: Samples of pubic symphysis were taken
from pregnant guinea-pigs sacrificed along gestation, parturition and
postpartum. Serial sections of paraffin-embedded tissues were used to
measure the interpubic distance on digitalized images, stained with
Giemsa to quantify leukocyte infiltration and to describe the vascular
area changes, or studied by the picrosirius-polarization method to
evaluate collagen remodeling. P4 and E2 serum levels were measured by a
sequential immunometric assay. RESULTS: Data showed that the pubic
relaxation is associated with an increase in collagen remodeling. In
addition, a positive correlation between E2 serum levels and the
increase in the interpubic distance was found. On the other hand, a
leukocyte infiltration in the interpubic tissue around parturition was
described, with the presence of almost all inflammatory cells types. At
the same time, histological images show an increase in vascular area
(angiogenesis). Eosinophils reached their highest level immediately
before parturition; whereas for the neutrophilic and mononuclear
infiltration higher values were recorded one day after parturition.
Correlation analysis showed that eosinophils and mononuclear cells were
positively correlated with E2 levels, but only eosinophilic
infiltration was associated with collagen remodeling. Additionally, we
observed typical histological images of dissolution of the connective
tissue matrix around eosinophils. CONCLUSION: The present study shows
that a timely regulated influx of infiltrating leukocytes is associated
with an extensive collagen remodeling process that allows the pubic
separation for a normal delivery in guinea-pig. Thus, the findings in
this study support the hypothesis that the guinea-pig pubic symphyseal
relaxation at parturition resembles an inflammatory process.