The effects of angiotensin II, catecholamines and glucocorticoid on CRF-induced ACTH release were examined using rat anterior pituitary cells in monolayer culture. Synthetic ovine CRF induced a significant ACTH release in this system. Angiotensin II produced an additive effect on CRF-induced ACTH release. The ACTH releasing activity of CRF was potentiated by epinephrine and norepinephrine. Dopa...

We investigated the molecular size of circulating immunoreactive ACTH by gel chromatography in patients with ACTH hypersecretion due to various disorders of the hypothalamic-pituitary-adrenal axis. 4 patients with Addison's disease, 2 with Nelson's syndrome, 4 with Cushing's disease, 6 with the ectopic ACTH syndrome (2 bronchial carcinoma, 1 medullary carcinoma, 1 metastatic islett cell carcino...

Immunoreactive ACTH was found in almost all tissue extracts of lung carcinoma from patients without clinical evidence of Cushing's syndrome; i.e. 14 of 15 primary tumors, nine of nine metastatic lymph nodes, and four of four metastatic liver nodules contained immunoreactive ACTH. The incidence of ACTH in extracts of other tumor types was much lower. Comparable normal tissues contained no detect...

Abstract Monitoring the concentration of glucocorticoid metabolites (GCMs) in faecal samples is a non-invasive tool for physiological stress evaluation, particularly useful when studying wild species. However, both negative and positive stimuli (distress eustress, respectively) can lead to rise glucocorticoids. Thus, besides validating whether GCM faeces reflects endogenous adrenal activity, we...

Neuromedin U (NMU) is a brain-gut peptide involved in the regulation of the hypothalamic-pituitary-adrenal axis and adrenocortical cell proliferation. In this study, we investigated the effects of NMU8 (three subcutaneous injections of 6.0 nmol/100 g, 24, 16 and 8 h before autopsy) on the adrenal glands of rats treated for 2 or 4 days with a low (2 microg/100 g body weight/24 h) or a high (8 mi...

A photoaffinity probe for corticotropin (ACTH) receptors was prepared by selective modification of the single tryptophan residue in ACTH. A new photoreactive agent, 2,4-dinitro-5-azidophenylsulfenyl chloride, was synthesized and used for introducing the photoreactive group into ACTH. 2,4-Dinitro-5-azidophenylsulfenyl-Trp9-ACTH (DNAPS-ACTH) was also prepared by thiolysis of 2,4-dinitrophenyl-sul...

Previous reports of adrenal progesterone (P4) contributions during late gestation in cattle, and ACTH-induced P4 responses in the non-pregnant heifer, prompted a retrospective investigation to evaluate the plasma P4 response and the relative ratio of plasma cortisol (CT) to P4 following ACTH administration during mid-gestation in pregnant Brahman heifers. Twenty-three pregnant (139.0 +/- 5.0 da...

Recently, during critical illness, cortisol metabolism was found to be reduced. We hypothesize that such reduced cortisol breakdown may suppress pulsatile ACTH and cortisol secretion via feedback inhibition. To test this hypothesis, nocturnal ACTH and cortisol secretory profiles were constructed by deconvolution analysis from plasma concentration time series in 40 matched critically ill patient...

Adrenal adenosine 3',5'-cyclic monophosphate (cAMP) and corticosterone responses to exogenous ACTH were found to be about 2.5 times greater in the evening (at lights off) than in the morning (at lights on) in rats. The rhythm in adrenal responsiveness to ACTH was found to persist in rats treated with dexamethasone 15 and 3 h before exogenous ACTH (in the presumed absence of a rhythm in endogeno...

A dramatic late-gestation increase in fetal plasma cortisol concentrations is critical for the timing of parturition in the sheep. This increase appears to depend upon an intact hypothalamo-pituitary unit and is characterised by increasing responsiveness of the fetal adrenal gland to ACTH. ACTH has been postulated as the critical determinant of the late-gestation cortisol increase; however, rec...