The Steroidogenic Response of Adult Rat Adrenocortical Cells in Monolayer Culture

Abstract

SUMMARY Quantitative aspects of corticosteroidogenesis were examined in monolayer cultures of cells from the zona fasciculata and zona reticularis of the adult rat adrenal cortex, maintained for up to 4 months. Corticosterone secretion continued at a steady rate in cultures maintained with corticotrophin (ACTH), the output of maximally stimulated cultures being approximately 12 μg/106 adrenocortical cells/day. In the absence of ACTH, a small amount of 20α-hydroxypregn-4-en-3-one, but no detectable corticosterone, was secreted, resulting in a fluorogenic steroid output 1/125 th of that of maximally stimulated cultures. Restimulation with ACTH of cultures maintained for up to 2 months in its absence resulted in maximum levels of corticosterone secretion after 4–5 days of continuous ACTH treatment. The levels of corticosterone secretion attained on restimulation were similar to those observed in cultures maintained with ACTH from the out set. Withdrawal of ACTH resulted in a fall in steroid output which took 10 days to reach final unstimulated levels. Trophic stimulation of corticosteroidogenesis with a similar time-course was obtained with both cyclic AMP and dibutyryl cyclic AMP, the latter being the more effective.

Cushing’s Syndrome due to Bilateral Adrenal Macronodular Hyperplasia with Undetectable ACTH: Cell Culture of Adenoma Cells on Extracellular Matrix

“…The strikingly high basal rate of cortisol secretion by these cells early in culture (day 2, table I) is comparable to cortisol secretion by normal human adrenocortical cells maximally stimulated by ACTH [15,16,29], This high in vitro cortisol secretion rate suggests that these cells are steroidogenically stimulated by a pathway inde pendent of ACTH, a conclusion that is consistent with the clinical picture of hypcrcortisolism in the absence of detectable plasma ACTH.…”

Hormonal Control of Adrenocortical Cell Proliferation

“…A progressive increase in steroidogenic capacity was seen in both freshly plated and subcultured cells; the same maximum rate of steroid production per cell was reached by day 4. The increasing steroidogenic capacity with prolonged cholera toxin treatment resembles that seen with prolonged ACTH treatment in other adrenal cell culture systems (7,(21)(22)(23) 5). By autoradiography, ACTH was shown previously to inhibit DNA synthesis in >98% of the cells (4).…”

Dissociation of tissue uptake of cholesterol ester from that of apoprotein A-I of rat plasma high density lipoprotein: selective delivery of cholesterol ester to liver, adrenal, and gonad.

“…One hour after injection, hepatocytes and adrenal cells were isolated as described (15,18) and their contents of 3H and 1"I were determined. The 1-hr time period was chosen to minimize hydrolysis of cholesterol esters and loss of radiolabeled cholesterol from tissues.…”