Table 3.

Stimulation of Transcription or Alkaline Phosphatase Activity by Various Progestins in T47Dco Cells

Steroid Hormone	EC50 for stimulation of PR-mediated transcription† (M)	Potency Ratio compared to progesterone*	EC50 for stimulation of alkaline phosphatase activity† (M)	Potency Ratio compared to progesterone*
Progesterone	3.1 ± 1.4 × 10−9a	1	1.9 ± 0.5 × 10−9a	1
17-OHPC	1.8 ± 0.4 × 10−9a,c	1.7	2.6 ± 1.3 × 10−9a	0.73
17-OHP	2.6 ± 0.8 × 10−6b	0.0012	1.3 ± 0.05 × 10−6b	0.0015
17-OHPA	6.9 ± 5.2 × 10−10c	4.5	4.5 ± 0.5 × 10−10c	4.2

^†Values represent the mean ± SE of 3–5 determinations.

^*EC₅₀ progesterone/EC₅₀ test progestin

^a,b,c Means with different letters are significantly different (p<0.05) from each other by one-way ANOVA followed by the Holm-Sidak multiple comparison test. EC₅₀’s were log₁₀ transformed prior to analysis.