Stress-induced increases in neonatal corticosterone demonstrate a unique shift from ACTH independence to ACTH dependence between postnatal day 2 (PD2) and day 8 (PD8) in newborn rats. This shift could be due to the binding of a bioactive, non--immunoreactive plasma ligand to the adrenocortical melanocortin 2 receptor (MC2R) (ACTH receptor). A potent MC2R antagonist would be useful to evaluate t...

Unlike the adult animal, the developing rat has a diminished ability to activate and inhibit the hypothalamic pituitary adrenal axis. In general, a gradual ACTH and corticosterone response to stressors appear after postnatal day 10 and is well established to adult level by weaning age. Although at this age the peak ACTH level is comparable to that of the adult, ACTH levels remain elevated for a...

Hypertension is a prominent feature of patients with Cushing's disease and ectopic adrenocorticotropic hormone (ACTH) syndrome, who have elevated ACTH levels. Chronic administration of ACTH (1-24) also raises blood pressure in humans. This effect has been postulated to be due to ACTH-induced increases in cortisol secretion in the adrenal gland. It is well known that cortisol increases vascular ...

We examined the cross-regulation of signaling between ACTH-and platelet-activating factor (PAF)-mediated steroidogenesis in the perfused guinea pig adrenal gland. Our method of in situ perfusion using an artificial medium can evaluate whether cortisol secretion in response to ACTH and PAF is interactive. Treating adrenal glands with 100 pg/ml ACTH diminished the subsequent cortisol response to ...

A coordinated hypothalamic-pituitary-adrenal axis response is important for the survival of newborns during stress. We have previously shown that prior to postnatal day (PD) 5, neonatal rats exposed to hypoxia (one of the most common stressors effecting premature neonates) exhibit a large corticosterone response with a minimal increase in immunoassayable plasma ACTH and without a detectable inc...

The adrenal cortex is a major stress organ in mammals that reacts rapidly to a multitude of external and internal stressors. Adrenocorticotropin (ACTH) is the main stimulator of the adrenal cortex, activating corticosteroid synthesis and secretion. We evaluated the mechanism of action of ACTH on adrenals of male rats, preserving the architecture of the gland in vitro. We demonstrated that both ...

Forty-eight patients receiving glucocorticoid treatment were tested with ACTH stimulation using alpha(1, 24) ACTH (tetracosactrin). All patients subsequently underwent non-acute major surgery without any glucocorticoid administration, and their clinical course and plasma corticosteroids were followed closely. No case of adrenocortical insufficiency was observed. A highly significant correlation...

Six patients who had experienced prolonged steroid-induced pituitary-adrenal suppression were treated with 100 U of depot procine ACTH every 2 to 4 days for several months. Such treatment did not hasten the recovery of normal pituitary-adrenal function compared with the rate of recovery of a group of similarly suppressed patients who received no depot ACTH. Eight of nine patients who received p...

Isolated ACTH deficiency causes life-threatening severe hypoglycemia. A 7-year-old girl with hypoglycemia due to this rare disorder is described. Our patient had undetectable plasma ACTH repeatedly and cortisol 0 mcg/dl before and after ACTH 1-24 stimulation. There was no evidence of other pituitary hormone deficiency. Glucocorticoid replacement therapy resulted in resolution of all symptoms an...

Raised plasma immunoreactive corticotrophin (ACTH) levels were found in five boys with the sex-linked disorder progressive leucodystrophy associated with adrenal insufficiency (Addison-Schilder's disease) and in a symptom-free brother of one of them. Similar ACTH concentrations were found using two antisera, one against the N-terminal part of the ACTH molecule and the other against the C-termin...