A method for the detection of ovulation in rats and evaluation of antiovulatory potency of various contraceptive steroids

Abstract

The female rats ovulates every 4 to 5 days, Presence of corpopa lutea in the ovaries indicates that ovulation has taken place. When an ovary is examined under the microscope, / several successive generations of corpora lutea may be seen. It is difficult to identify the corpora lutea of recent ovulation from the older generations. A method has been developed which makes possible the identification of "fresh" corpora lutea of the recent ovulation from those of the previous generations. The method consists in the intraperitonial administration of 4 ml of 1% Dianil Blue 2R Solution during the last four days prior to autopsy. The vital dye selectively stains the previous generations of corpora lutea. The "fresh" corpora lutea of the recent ovulation remains unstained.