Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UNIPROT:P01189 (beta-endorphin)
 21,003 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

This study explores the possibility of improving endocrinologic testing during petrosal sinus catheterization by determining both beta-endorphin and corticotropin (ACTH). We studied 14 patients with Cushing's disease, two with adrenal tumor, and three with ectopic tumors secreting ACTH. In patients with Cushing's disease, beta-endorphin concentrations paralleled those of ACTH in all basal plasma samples collected either from petrosal sinuses or peripheral veins. Individual responses of beta-endorphin and ACTH to corticotropin releasing hormone (CRH) were closely related to the presence of a corticotroph adenoma. In such patients, a consistently higher concentration of beta-endorphin over ACTH was observed in all samples collected either from petrosal sinuses or peripheral veins; the ratios were unchanged after the administration of CRH. In patients with ectopic ACTH secretion, the mean ratio of beta-endorphin over ACTH (with both values expressed in pmol/L) was significantly higher (3.5) than that of patients with Cushing's disease (2.9) or Cushing's syndrome due to adrenal tumor (2.7).
 ...
PMID:Parallel assays of beta-endorphin and ACTH in Cushing's patients undergoing petrosal sinus sampling. 217 14

A 36-year-old patient developed marked pigmentation, marked myopathy and severe hypokalaemic alkalosis which at first pointed towards an ectopic ACTH syndrome. The dexamethasone test at a high dose indicated cortisol suppression. A mediastinal tumour was seen radiologically, but the sella was of normal size. Computed tomography provided indirect signs of a sellar space-occupying lesion which suggested an ectopic production of corticotropin-releasing factor (CRF) as cause of the Cushing's syndrome. CRF concentration in antecubital venous blood was markedly elevated to 280 ng/l. The mediastinal tumour was excised and proved to be a carcinoid histologically. Postoperatively the CRF concentration fell to 70 ng/l. An extract of the carcinoid contained 15.5 ng/g wet-weight of CRF and 254 ng/g wet-weight of beta-endorphin. The patient died 5 weeks postoperatively of sepsis with bilateral pneumonia. At autopsy the hypophysis was of normal size but showed nodular ACTH-cell hyperplasia. This was thus a case of Cushing's syndrome resulting from ectopic CRF production in a mediastinal carcinoid tumour.
 ...
PMID:[Cushing's syndrome in CRF-producing mediastinal carcinoid]. 230 1

A 64 year old woman with a pancreatic islet cell tumor developed Cushing's syndrome. Glucocorticoid secretion did not decrease after low or high dose dexamethasone administration, and the Cushing's syndrome was cured by removal of tumor tissue. Immunohistochemistry and radioimmunoassays revealed the presence of immunoreactive ACTH, beta-endorphin and alpha-MSH in the tumor cells. Gel-permeation chromatography confirmed that beta-endorphin was the predominant opioid peptide produced by the tumor. The tumor was shown to contain a single 1.2 kilobase RNA species which hybridized to a 32P human POMC-cDNA; this POMC RNA was identical in size to that isolated from a normal human pituitary. In dispersed monolayer culture, CRF failed to elicit ACTH release from the tumor cells, but dexamethasone caused a paradoxical increase in ACTH secretion in vitro. This study demonstrates that aberrant regulation of POMC synthesis and peptide processing can be seen in tumors which synthesize a POMC RNA identical in size to that made in the pituitary gland.
 ...
PMID:Aberrant production and regulation of proopiomelanocortin-derived peptides in ectopic Cushing's syndrome. 245 59

Previous reports on patients with endogenous Cushing's syndrome describe low concentrations of the adrenal androgen dehydroepiandrosterone sulfate (DHEA-S) in adrenal adenoma and in a case of feminizing macronodular hyperplasia. Here we present hormonal data from two adult sisters with Cushing's syndrome as a result of pigmented nodular adrenal dysplasia. Corticotropin concentrations were in the mid-normal range, cortisol production was unaffected by administration of dexamethasone (8 mg/24 h), and baseline concentrations of DHEA-S were less than 0.5 mumol/L. A low concentration of DHEA-S in these and other previously reported patients with Cushing's syndrome correctly predicts the results of dynamic testing. Decreased DHEA-S in a patient with endogenous Cushing's syndrome can be ascertained by assay of a single sample and should prompt consideration of the diagnosis of autonomous bilateral nodular disease as well as adrenal adenoma.
 ...
PMID:Decreased dehydroepiandrosterone sulfate in pigmented nodular adrenal dysplasia. 253 Oct 49

Corticotropin-releasing hormone, a 41-amino-acid peptide, is an important hypothalamic factor regulating the pituitary secretion of adrenocorticotropic hormone (ACTH). This hormone, while rarely involved in the etiology of Cushing's syndrome, seems to play a major role in the pathogenesis of non-Cushing hypercortisolemic states. The administration of synthetic human and ovine CRH has been found useful in the differential diagnosis of Cushing's syndrome and in the preoperative localization of intrasellar ACTH-secreting tumors.
 ...
PMID:Corticotropin-releasing hormone: clinical applications. 254 67

We studied a 40-year-old woman with cyclic Cushing's syndrome who demonstrated abnormal high-dose dexamethasone suppression and metyrapone stimulation tests. These results, associated with persistent elevations of plasma adrenocorticotropic hormone (ACTH) levels, suggested ectopic secretion of ACTH. Surprisingly, an adrenal adenoma with atrophy of the contralateral adrenal gland was found at exploratory laparotomy. Subsequent ACTH determinations that extract ACTH from the plasma before assay suggested that the apparent increase in ACTH concentration in our routine assay was due to the presence of an interfering substance(s). We conclude that the diagnosis of Cushing's syndrome continues to depend on a battery of adrenal function tests and radiographic procedures and recommend that measurements of ACTH be performed only after extraction of ACTH from specimens.
 ...
PMID:Spurious elevation of plasma immunoreactive adrenocorticotropic hormone in cyclic Cushing's syndrome. 254 79

The effects of 2-day and 7-day cortisol treatment on immunoreactive corticotropin (ACTH) and beta-endorphin concentrations were measured in the cerebral cortex, hippocampus, hypothalamus, and cerebellum in male rats. Plasma ACTH, beta-endorphin, corticosterone, and cortisol levels were also measured in parallel. Cortisol administration by osmotic minipumps (25 mg/kg/day) maintained a constant, moderately high concentration (23.0 +/- 2.7 micrograms/100 ml) of this glucocorticoid in plasma. Two-day cortisol treatment suppressed the plasma concentration of ACTH and corticosterone, and also decreased, to a lesser degree, concentrations of beta-endorphin. ACTH and beta-endorphin levels in the brain remained unchanged after 2 days of cortisol treatment. After 7-day treatment, however, plasma concentrations of ACTH and beta-endorphin further decreased, while ACTH and beta-endorphin concentrations in the cortex and beta-endorphin concentrations in the cerebellum were also significantly decreased. Peptide concentrations in other brain areas did not change significantly with either 2-day or 7-day cortisol treatment. These data suggest that there are delayed effects of glucocorticoids on pro-opiomelanocortin peptide secretion and/or metabolism in the central nervous system. These findings are consistent with the impaired cognitive functions of patients with diseases, such as Cushing's syndrome and depression, that have long-lasting elevated cortisol secretion.
 ...
PMID:Delayed effects of chronic cortisol treatment on brain and plasma concentrations of corticotropin (ACTH) and beta-endorphin. 254 10

In addition to prolonged glucocorticoid therapy (not discussed here), at least five other conditions cause Cushing's syndrome. They are excessive corticotropin secretion by the pituitary gland (which results in Cushing's disease), ectopic production of corticotropin by malignant nonpituitary tumors, benign adrenal adenoma, adrenal carcinoma, and primary adrenocortical nodular dysplasia. Each can be distinguished by a specific pathophysiologic process that triggers the adrenal glands to overproduce glucocorticoids. At present, diagnosis of Cushing's syndrome or disease relies heavily on the dexamethasone (Decadron, Hexadrol) suppression test. After diagnosis, other studies, including computed tomography, magnetic resonance imaging, and corticotropin radioimmunoassay, can be used to localize the site of the lesion. Treatment, of course, depends on the underlying cause.
 ...
PMID:Cushing's syndrome. How to pinpoint and treat the underlying cause. 255

The combined intravenous injection of TRH and GnRH elicited paradoxical responses of plasma beta-endorphin in active and successfully treated pituitary dependent Cushing's disease as well as in ectopic ACTH syndrome and in congenital adrenal hyperplasia. No response was observed in Cushing's syndrome due to adrenal tumours. It is concluded that an abnormal response to inappropriate releasing hormones cannot verify the existence of a pituitary corticotrophic microadenoma.
 ...
PMID:Paradoxical response of plasma beta-endorphin to combined administration of TRH and GnRH in adrenal disorders. 255 25

Altogether 28 patients with adrenocortical tumors (corticosteromas and corticoandrosteromas) were examined using a radioimmunoassay to determine the concentration of corticotropin, cortisol, blood cyclic nucleotides, the circadian rhythm and time course of corticotropin and cortisol levels against a background of insulin hypoglycemia. In patients with Itsenko-Cushing's syndrome the basel level of cortisol was notably raised, that of corticotropin was sharply decreased. The circadian rhythm of the levels of corticotropin and cortisol was disturbed, a response of the hypophyseal-adrenal system to a stressor was suppressed. The concentration of blood cyclic nucleotides was increased, and these changes were dependent on the nature of adrenal pathology.
 ...
PMID:[The function of the hypothalamo-hypophyseal-adrenal system in Itsenko-Cushing syndrome]. 256 Jan 86


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>