Antifertility Effect of Cs-1 in the Rat

Abstract

In rats, CS-1 (5 mg) totally prevents implantation when administered by mouth during the first 8 days post coitum, but has no influence on pregnancy if treatment is initiated after the 13th day of gestation. The antifertility effect of this compound is abolished by the simultaneous injection of progesterone or prolactin. CS-1 might depress the production of pituitary luteotrophic hormone, thereby interfering with the secretory function of the corpus luteum and diminishing the supply of progesterone below the level required to maintain pregnancy.