Studies on the role of protein synthesis in the regulation of corticosterone production by adrenocorticotropic hormone in vivo.

Abstract

The primary event following the administration of adrenocorticotropic hormone (ACTH) is the immediate increase in steroid synthesis by the adrenal gland.1 Previous studies by numerous investigators suggested that this action of ACTH was the result of specific activation of enzymes.2' 3 However, studies showing that puromycin or chloramphenicol blocked the stimulation of corticosterone synthesis by ACTH suggested that protein synthesis was involved in this process.4 5 But

Kinetics and dose—response characteristics of adenosine 3′,5′‐monophosphate production by isolated rat adrenal cells stimulated with adrenocorticotrophic hormone

“…If cyclic AMP is involved in ACTH action, thi~ lag could represent the time needed for accumulation of sufficient cyclic AMP to stimulate steroidogenesis. Alternatively, this time may be necessary for the operation of processes initiated by cyclic AMP, such as synthesis of the labile protein postulated by Garren [13]. The latter possibility is more likely, as addition of 5 mM cyclic AMP to ceils results in a time lag of about 3 min before corticosterone is produced [ 14].…”

The effect of calcium ions on the metabolism of exogenous cholesterol by rat adrenal mitochondria

“…The pregnenolone production in the adrenal mitochondria from ether-stressed animals is much greater than those from cycloheximide-treated animals. Cycloheximide treatment of rats is thought to block the production of a factor important in the control of the metabolism of cholesterol by adrenal mitochondria [3]. Calcium ions have been reported to be important in controlling cholesterol metabolism [6].…”

“…Trophic hormone action could provide this cholesterol by promoting the hydrolysis of cholesterol esters in cellular lipid droplets by cholesterol esterase [15]. The rapidly turning over factor [3] proposed to be involved in the control of adrenal steroidogenesis probably does not promote transport of cholesterol into the mitochondrion. Adrenal mitochondria isolated from ether-stressed rats contain less cholesterol (16.0 nmol/ mg protein) compared to those obtained from cycloheximide-treated animals (27.0 nmol/mg protein) but the former mitochondria are capable of producing more pregnenolone in the presence of exogenous cholesterol ( fig.l).…”

“…The rate-limiting step of adrenal steroidogenesis is the conversion of cholesterol to pregnenolone which occurs in the mitochondria of adrenocortical cells [1,2]. Since the trophic effect of ACTH with relation to increased corticosteroid production is prevented by prior treatment of the animal with cycloheximide the involvement of a putative protein factor in the regulation of the cholesterol desmolase system has been proposed [3]. There have also been reports which implicate calcium ions in the response of steroidogenic tissues to trophic hormone stimulation [4][5][6][7].…”

Hormone‐induced changes in cardiolipin from leydog cells: Possible involvement in intramitochondrial cholesterol translocation

“…Several studies have demonstrated that this mechanism is dependent on a cycloheximide-sensitive and highly labile protein which is rapidly synthesized on stimulation of steroidogenic cells (3)(4)(5). Among the leading candidates for such a pivotal protein factor is Steroidogenic Acute Regulatory protein (STAR) described by Orme-Johnson and Stocco (6,7) which has been shown to fulfill all the criteria predicted for the regulatory protein (reviewed in (ref.…”