Hormone levels in tumors. (A) Effect of hormone treatment on 5αP and 3αHP levels in tumors. Hormone levels in tumors from four vehicle-injected, five 5αP-treated, and four 3αHP-treated mice were determined with RIA, as described in Methods. Hormone levels are presented as nanograms per milliliter 5αP and 3αHP and (B) as the ratio of 5αP to 3αHP. (**P < 0.01 for the comparison between 5αP and 3αHP levels). (C) Levels of 5αP, 3αHP, and progesterone (Pro) in tumors and respective sera from nine mice were determined after extraction with organic solvents and separation by thin-layer chromatography (TLC) as described in Methods. Levels of hormones are presented as nanograms per milliliter (serum) and nanograms per milligram (tumors), and (D), as the ratio of 5αP to 3αHP. **, ***Significantly different from serum levels at P < 0.01 and P < 0.001, respectively.