Figure 5.

Secretion of [³H] steroid by ^1–24ACTH-stimulated Y1-BS1 cells incubated with [³H]hHDL₃. Y1-BS1 cells were incubated for 24 hr with 25 μg protein/ml [³H]hHDL₃ in the presence or absence of 1 mM aminogluthethimide. Steroids were extracted from the medium with CH₂Cl₂ and separated by HPLC as described. (A and B) Absorbance profile at 240 nm and the radioactivity profile, respectively. Arrows in A indicate the elution position of standards: corticosterone (I), 11β-hydroxyprogesterone (II), 20α-hydroxyprogesterone (III), and progesterone (IV).