| Abstract: | Nine healthy women of fertile age were administered orally with mifepristone 25,100,400and 600mg in one single dose respectively in late luteal phase of 4 successive cycles,and received blood sampling before treatment and 4,8,12,24,48,72,96 and 120 h after treatment for determination of serum ACTH and cortisol levels.In addition, fifteen healthy fertile women were divided Into three groups at random and administered with mifepristone 25mg q12h×6 respectively in early,mid-and late luteal phase of one cycle,blood samples were taken each morning for measurement of ACTH,cortisol as well as mifepristone levels.The results showed that mifepristone 25 and 100mg in single dose had no effects on serum levels of ACTH、cortisol and their diurnal rhythms,while one single high dose(400 or 600mg)of the compound induced marked increase in ACTH and cortisol levels with significant reduction of their diurnal changes.In contrast,serum ACTH,cortisol and mifepristone levels had no significant changes after administration of the compound in multiple low doses during various period of luteal phase.The results of this study indicated that mifepristone presented its antiglucocorticoid activity in dose-dependent mannar,one single high dose of mifepristone(400mg or more)affected the diurnal rhythms of ACTH and cortisol secretion,and there were no significant differences in absorption and effects on pituitary-adrenal axis of the compound used in different periods of luteal phase. |
