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THE TIMING AND POSSIBLE MECHANISMS OF CERVICAL OPENING IN THE OESTROUS RAT
Author(s) -
Foulkes A.,
Bradshaw Jane M. C.,
Porter D. G.
Publication year - 1982
Publication title -
quarterly journal of experimental physiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.925
H-Index - 101
eISSN - 1469-445X
pISSN - 0144-8757
DOI - 10.1113/expphysiol.1982.sp002627
Subject(s) - estrous cycle , cervix , ovariectomized rat , uterus , stimulation , endocrinology , medicine , relaxin , chemistry , implant , andrology , hormone , surgery , cancer
The time that the retention of luminal fluid begins and its release from the uterus in pro‐oestrous rats was determined precisely using a dye injection technique. Oestradiol was found to cause dye retention in ovariectomized rats when provided continuously from an implant of 5 mg. Injections of 0·5 µg/d x 4 were ineffective. Administration of progesterone to rats bearing implants of oestrogen interfered with the ability of the uterus to retain dye. Treatment with relaxin for 28 h prevented retention of dye in pro‐oestrous rats whereas treatment at the time of dye injection was without effect. Mechanical stimulation of the cervix did not cause loss of injected dye. It is suggested that the mechanisms of opening of the cervix at coitus and at the end of oestrus may differ.