Abstract
In this study, the histomorphological changes induced by 5α-norethisterone (5α-NET),
a reduced metabolite of the contragestational postcoital agent norethisterone, in
the oviduct and the uterus of the pregnant rabbit were determined. Adult fertilized
rabbits were treated daily with 5α-NET (1.0, 1.5, 2.5, and 5.0 mg/kg/day) during 7
consecutive days, starting from the first day after coitus. Twenty-four hours after
the last administration, the histological analysis of the oviduct and the uterus was
performed. It was observed that in the infundibulum-ampullae region as well as in
the isthmus of the oviduct, the number of nonsecretory cells (PAS-negative) were decreased,
whereas the number of secretory cells (PAS-positive) were increased significantly
after 5α-NET administration. The proportion of glandular tissue in the uterus markedly
diminished in relation to that of the stromal tissue. This indicates an inhibition
of the endometrial transformation observed during normal pregnancy. Interestingly,
the highest doses of 5α-NET (2.5 and 5.0 mg/kg/day) induced necrosis in the uterus
but not in the oviduct. These results suggest that the molecular antiprogestational
effects previously observed after 5α-NET administration are also related to changes
in the histomorphology of both the oviduct and the uterus of the pregnant rabbit.
Keywords
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Article info
Publication history
Accepted:
March 20,
1998
Received in revised form:
March 6,
1998
Received:
January 16,
1998
Identification
Copyright
© 1998 Elsevier Science Inc. Published by Elsevier Inc. All rights reserved.
