Extraction of corticosterone from cell homogenates and subcellular fractions of the rat adrenal cortex. III. ACTH-induced temporal subcellular redistributions of steroid precursors to corticosterone.

Published

Journal Article

Cholesterol, pregnenolone, progesterone, 11-deoxycorticosterone (11-DOC) and corticosterone were quantitated in subcellular fractions isolated from in vivo adrenocorticotropin (ACTH)-stimulated rat adrenal zona fasciculata/reticularis. Six adrenal subcellular fractions separated by discontinuous sucrose gradient centrifugation (lipid, 0.125 M sucrose, cytosolic, microsomal, mitochondrial and nuclear) were extracted with alkaline ether/ethanol and assayed by high pressure liquid chromatography (HPLC). Lipid fractions contained the major cholesterol stores, while most pregnenolone and progesterone was found in lipid, microsomal and mitochondrial fractions. The 0.125 M sucrose and cytosol fractions together contained approximately 75% of the total 11-DOC and corticosterone. The five steroids were only present in small amounts in organelle fractions containing steroidogenic enzymes. Homogenate and lipid fraction cholesterol decreased between 10 and 15 min and again 30 min after ACTH injection. In the homogenate, lipid, microsomal and mitochondrial fractions, pregnenolone and progesterone were increased after ACTH injection; peak pregnenolone and progesterone concentrations were often measured in adrenal gland sucrose, cytosolic, microsomal and mitochondrial fractions 15 to 20 min after rats were injected with ACTH. Although ACTH increased 11-DOC and corticosterone in all but the mitochondrial and nuclear fractions, the sucrose, cytosolic and microsomal 11-DOC, and cytosolic corticosterone increased most dramatically. In many fractions, peak 11-DOC and corticosterone concentrations were most often observed between the 10 and 15 min periods and again at 30 min.

Full Text

Cited Authors

  • Mathew, J; Sallee, VL; Curtis, J; Mrotek, J

Published Date

  • August 1985

Published In

Volume / Issue

  • 46 / 2-3

Start / End Page

  • 697 - 716

PubMed ID

  • 3016951

Pubmed Central ID

  • 3016951

Electronic International Standard Serial Number (EISSN)

  • 1878-5867

International Standard Serial Number (ISSN)

  • 0039-128X

Digital Object Identifier (DOI)

  • 10.1016/0039-128x(85)90050-9

Language

  • eng