INVESTIGADORES
RAMOS Jorge Guillermo
artículos
Título:
Role of relaxin and estrogen in the control of eosinophilic invasion and collagen remodeling in rat cervical tissue at term
Autor/es:
LUQUE EH; MUÑOZ DE TORO M; RAMOS JG; RODRÍGUEZ HA; SHERWOOD OD
Revista:
BIOLOGY OF REPRODUCTION
Referencias:
Año: 1998 vol. 59 p. 795 - 800
ISSN:
0006-3363
Resumen:
Ripening and dilation of the rat cervix at term involves a widespread
reduction in the density and organization of collagen fibers following
a polymorphonuclear eosinophilic invasion. These are hormonally
regulated events; however, the correlation between hormonal milieu and
these morphological changes is not well understood. To investigate the
role of preparturient relaxin and estradiol-17ss (E2) in cervical
collagen remodeling and eosinophilic infiltration, pregnant rats were
either sham-ovariectomized (group C) or ovariectomized in the morning
of Day 22. Ovariectomized rats were treated with E2 (group OE), relaxin
(group OR), E2 plus relaxin (group OER), or hormone vehicles (group O).
There were 4 or 5 animals per group. Cervices were taken from animals
killed approximately 1 h before expected parturition. Five-micrometer
serial sections of paraffin-embedded cervices were stained with either
Sirius Red in alkaline solution to measure eosinophil infiltration or
in Picrosirius to measure collagen birefringence. Ovariectomized rats
treated with E2 (group OE or OER) showed high levels of eosinophilic
infiltration that did not differ from those in group C intact controls.
However, the values of eosinophilic infiltration in ovariectomized rats
treated with relaxin or hormone vehicles (groups OR and O) were low and
far below (p < 0.01) those of groups OE and C. In ovariectomized
rats treated with E2 alone (group OE), the widespread reduction in
collagen organization that occurred in group C controls was not
observed. It was only in ovariectomized rats treated with relaxin or E2
+ relaxin (groups OR and OER) that the values of birefringence were
low, and they were as low as in control group C. In conclusion, this
study indicates that eosinophilic infiltration and collagen remodeling
in the rat cervix at term are under the control of different hormones:
E2 stimulates eosinophilic invasion, and relaxin promotes a widespread
reorganization of collagen fibers.