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

1. A new line of cloned, differentiated rat hepatocytes (RL-PR-C) was evaluated for its usefulness as an in vitro system for studying the regulation of the insulin receptor. 2. Insulin rapidly reversibly and specifically bound to RL-PR-C hepatocytes. Binding of tracer 125I-labeled insulin, which was competitively inhibited by native insulin as well as by proinsulin and analogs of insulin and proinsulin in proportion to their biological activity, was not influenced by glucagon, corticotropin, or human growth hormone. Anti-insulin receptor serum from a patient with Acanthosis Nigricans Type B competed with 125I-labeled insulin for binding to cell surface sites. 3. Trypsinization destroyed insulin binding sites, but these were restored by incubation under growth conditions; a 75% restoration of binding sites was achieved by one cell population doubling. 4. RL-PR-C hepatocytes responded to insulin binding by an increase in glycogen synthesis from glucose. The insulin effect was maximal at 85 nM, but was detectable at lower, more physiological, concentrations. 5. Chronic exposure (for at least 3h) of hepatocytes to insulin (10(-10)--(10(-8) M) reduced by up to 60% the number of binding sites for insulin (down-regulation). Down-regulation was prevented by cycloheximide at concentration (10 micron) sufficient to inhibit markedly protein synthesis from tracer isoleucine. Recovery from down-regulation induced by native insulin at 10(-7 M or lower concentrations was complete by 18 h under growth conditions. 6. Although RL-PR-C hepatocytes spontaneously transform after about 90 population doublings, no significant differences between normal and transformed cells were observed in insulin binding characteristics and in interaction of cells with anti-insulin receptor serum. However, transformed cells exhibited a substantially reduced (maximum of 20%) down-regulation response to insulin. 7. RL-PR-C rat hepatocytes appear, for these reasons, to be a useful model system for studying the regulation of the insulin receptor.
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PMID:Hormone receptors. 7. Characteristics of insulin receptors in a new line of cloned neonatal rat hepatocytes. 56 93

We previously reported that circulating beta-endorphin levels are increased in obese hirsute women and that plasma immunoreactive insulin (IRI) levels are increased in proportion to the degree of hyperandrogenism in women with the polycystic ovary (PCO) syndrome. We, therefore, tested the hypothesis that endogenous opiates are at least partially responsible for the hyperinsulinemia and insulin resistance in this syndrome. In the first study, acute naloxone administration significantly reduced the plasma IRI response and IRI/glucose ratio in three euglycemic obese women with PCO and acanthosis nigricans (AN) and marked insulin resistance, but did not alter the glucose response. Naloxone had no effect on these parameters in the normal weight control subjects. In the second study, nalmefene, a new, orally active opiate antagonist, reduced IRI and the IRI/glucose ratio in four women with PCO-AN and marked hyperinsulinemia in a randomized, double blind, crossover protocol. We conclude that endogenous opiates are at least partially responsible for the hyperinsulinemia and insulin resistance in PCO-AN.
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PMID:Reduction of hyperinsulinemia and insulin resistance by opiate receptor blockade in the polycystic ovary syndrome with acanthosis nigricans. 353 80

The association of acanthosis nigricans with pituitary tumors and insulin-resistant diabetes suggests that a pituitary peptide may promote papillomatosis and acanthosis characteristic of acanthosis nigricans. Although such a peptide has not been isolated, it may derive by sequential cleavage from the 31,000-dalton precursor peptide to ACTH and beta-lipotropin (beta-LPH). In order to evaluate the role of pituitary peptides in the pathogenesis of acanthosis nigricans, we compared plasma levels of beta-endorphin (beta-EP) and ACTH in plasma of 8 fasting patients with obesity-associated benign acanthosis nigricans and 7 fasting normal controls utilizing sensitive radioimmunoassay procedures. Mean plasma beta-EP levels for the acanthosis nigricans and control subjects were not significantly different (90 pg/ml vs. 140 pg/ml), nor was any significant difference observed between plasma ACTH levels of the 2 groups (42.3 and 31.2 pg/ml, respectively.) Our data indicate that plasma levels of the pituitary-derived peptides ACTH and beta-EP are not increased in obesity-associated benign acanthosis nigricans, and suggest that its proposed hormonal mediator might originate independently from the large peptide precursor of ACTH, beta-LPH and their fragments.
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PMID:Neuropeptides in the pathogenesis of obesity-associated benign acanthosis nigricans. 629 89

The skin serves as a window for clinicians to understand, diagnose, and monitor endocrine disease. Dermatologic manifestations of endocrinopathies contribute significantly to an individual's health and quality of life. In this review, we outline various disorders of the hypothalamic-pituitary axis, thyroid gland, pancreas, adrenal gland, and androgen axis as well as hereditary endocrine syndromes. In acromegaly, glycosaminoglycan deposition contributes to a thickening of skin and soft tissue, which manifests as coarsening and enlargement of facial and acral structures. Stimulation of the thyrotropin receptor in hyperthyroidism results in mesenchymal tissue proliferation and consequent pretibial myxedema; other associated cutaneous features include onycholysis, and hyperhidrosis. Individuals with hypothyroidism exhibit cold, dry skin and brittle hair as well as a jaundice-like appearance due to carotene excess. The cutaneous features of diabetes mellitus (DM), mediated to a large extent by hyperglycemia and hyperinsulinemia, include necrobiosis lipoidica diabeticorum (NLD), diabetic dermopathy, and acanthosis nigricans. Pediatric patients with Cushing's syndrome almost invariably present with truncal obesity and growth retardation; disruption of collagen formation and the catabolic effects of hypercortisolism result in skin atrophy and purple abdominal striae. In patients with Addison's disease, generalized hyperpigmentation, secondary to elevated levels of melanocyte-stimulating hormone (MSH), is most prominent in sun-exposed areas. Due to hyperandrogenism, individuals with polycystic ovarian syndrome (PCOS) often exhibit hirsutism, acne vulgaris, and androgenetic alopecia. In multiple endocrine neoplasia (MEN) syndromes, specific gene mutations may lead to angiofibromas, lichen amyloidosis, and ganglioneuromas. Disruptions of immune regulation result in autoimmune polyglandular syndromes (APS) and associated clinical features including chronic mucocutaneous candidiasis, vitiligo, and alopecia areata. This paper highlights the underlying pathophysiology, dermatologic manifestations, and treatment of the aforementioned endocrine disorders.
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PMID:Dermatologic manifestations of endocrine disorders. 2918 11