Fig. 5.
PROG analogs have a broad range of potencies for eliciting calcium influx in human sperm. (A) Representative FLIPR traces showing the concentration-dependent increase in calcium influx produced by PROG. (B) Concentration-response curves comparing potencies of parent compound PROG and C17- and/or C6-modified analogs: 1, PROG; 4, MPA; 20, 6α-methylprogesterone; 25, 17α-hydroxyprogesterone; 29, 17α-acetoxyprogesterone; 30, 17α-hydroxy-6α-methylprogesterone. Data are plotted as mean ±SEM and expressed as a percent of the response produced by a saturating concentration of PROG (3 µM). EC50, Emax, and n values are in Tables 2 and 3.