Corticotrophin-releasing factor-like immunoreactivity and bioactivity of human fetal and adult hypothalami.

Corticotrophin releasing factor-like immunoreactivity (CRF-LI) and bioactivity, and arginine vasopressin-like immunoreactivity (AVP-LI) have been measured in extracts of human fetal and adult hypothalamic tissue and their development with the gestational age of the fetuses (12-27 weeks) studied. CRF-LI was measured by a radioimmunoassay developed for ovine corticotrophin-releasing factor (oCRF-41). Corticotrophin-releasing factor bioactivity was measured in a rat isolated anterior pituitary cell perfusion system.

A case of pituitary dependent Cushing's disease with clinical and biochemical features of the ectopic ACTH syndrome.

A case of atypical pituitary dependent Cushing's disease is reported. The patient presented with clinical symptoms similar to those of the ectopic ACTH syndrome; notably a marked hypokalaemic alkalosis, widely fluctuating plasma cortisol levels, greatly elevated plasma ACTH levels, and failure to suppress both plasma cortisol and ACTH levels following high dose oral dexamethasone. However, a large aggressive pituitary tumour was detected by skull X-ray and computed tomography.

Measurement of immunoreactive gamma-MSH in human plasma.

A radioimmunoassay for immunoreactive gamma-MSH (IR-gamma-MSH) in human plasma has been developed. The assay is capable of detecting normal basal circulating levels which range from less than 20-100 ng/1 at 0900 h. Plasma levels are raised concomitantly with ACTH during insulin induced hypoglycaemia and CRF stimulation and suppressed with dexamethasone.

Corticotrophin-releasing factor--mediated adrenocorticotrophin release from rat anterior pituitary cells is potentiated by C-terminal gastrin-releasing peptide.

The remission of Cushing's syndrome following surgical removal of a tumour containing bombesin-like immunoreactivity (BLI), but insignificant levels of ACTH, is described. However, an acid extract of the tumour tissue caused the release of ACTH from isolated rat anterior pituitary cells in vitro. These observations led to an investigation of the effects of synthetic C-terminal gastrin-releasing peptide (GRP(14-27] on ACTH release from isolated rat anterior pituitary cells.

Regional distribution of pro-opiomelanocortin-derived peptides in the human brain.

The regional distribution of pro-opiocortin-derived peptides and methionine enkephalin was investigated in human brain post-mortem. Sequence-directed radioimmunoassays for beta-endorphin, gamma-lipotropin, adrenocorticotrophin, corticotrophin-like intermediate lobe peptide (ACTH18-39, CLIP) alpha-MSH and methionine enkephalin were used and 40 different human brain areas were assayed. The regional distribution of all the pro-opiomelanocortin-derived immunoreactivities were correlated with highest amounts of beta-endorphin, gamma-lipotropin and ACTH in the hypothalamus, amygdala, periventricular grey, substantia nigra and superior colliculus.