radioimmunoassays of progesterone , 17 alpha-hydroxyprogesterone , androstenedione , testosterone and 17 beta-oestradiol were used to measure the steroid concentrations in plasma for 6 days after the initiation of follicular development with pregnant mare 's gonadotropin , and the long-term and acute effects of choriogonadotropin on these circulatory concentrations .
C0018061
gonadotropin
C0018062
choriogonadotropin