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)

The adenylate cyclase responses of the human GH or ACTH producing pituitary adenomas and ectopic ACTH producing tumors to TRH, LH-RH, biogenic amines, peptides hormones, PGE1 and rat median eminence extract (MEE) have been examined. Out of 4 GH producing pituitary adenomas obtained from patients with active acromegaly at hypophysectomy two were stimulated by TRH, two by LH-RH, three by norepinephrine, one by dopamine, four by PGE1 and none by serotonin. Glucagon stimulated the adenylate cyclase in one of three and MEE in both of two tested. The positive responses of paradoxical GH release after TRH and/or LH-RH before surgery in these patients coincidentally related to the response of adenylate cyclase of each pituitary adenoma. There seems, however, to be no consistent correlation between the adenylate cyclase responses to biogenic amines and the GH release after L-Dopa or 5-hydroxytroptophan tested. The adenylate cyclase of a pituitary adenoma from case of Cushing's disease was stimulated by LH-RH, norepinephrine glucagon and MEE but not by TRH. Plasma levels of ACTH, beta-MSH and cortisol increased after LH-RH but not after TRH in this patient before hypophysectomy. The adenylate cyclase of two ectopic ACTH producing tumors (gastric carcinoid and malignant thymoma) was activated by TRH, LH-RH, norepinephrine, epinephrine, serotonin, PGE1 and MEE. These results indicate the presence of multiple hormone receptors in GH or ACTH producing pituitary adenomas and ectopic ACTH producing tumors, and suggest that the paradoxical GH or ACTH release after TRH and/or LH-RH injection in acromegaly and Cushing's syndrome might be caused by an alteration of the cellular membrane receptors of the pituitary adenomas.
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PMID:Adenylate cyclase of GH and ACTH producing tumors of human: activation by non-specific hormones and other bioactive substances. 19 Feb 56

A sensitive and specific radioimmunoassay for human beta-lipotropin (betah-LPH) in unextracted plasma was developed using pur betah-LPH as tracer and standard and an antiserum not cross-reacting with human beta-MSH and hACTH. In healthy volunteers plasma betah-LPH ranged from less than 20 to 150 pg/ml at 8:00 a.m. and rose after metyrapone administration. betah-LPH was very low in panhypopituitarism, normal in most patients with untreated Cushing's disease, elevated in acromegaly and extremely high in Nelson's syndrome.
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PMID:Radioimmunoassay of human beta-lipotropin in unextracted plasma. 92 35

Treatment with Sandostatin is established in acromegaly, thyroid-stimulating hormone (TSH)-producing pituitary, and endocrine-active gastroenteropancreatic tumors. Potential indications include ectopic hormone syndromes, medullary thyroid carcinomas, pituitary resistance to thyroid hormones, tall stature children, diabetes mellitus and diabetic complications, polycystic ovary syndrome, and Graves' ophthalmopathy. Particularly in the ectopic growth hormone-releasing hormone (GHRH) syndrome, Sandostatin is unequivocally effective and, in the ectopic corticotropin syndrome selected cases can be treated successfully with Sandostatin, leading to marked clinical improvement. In many of the above situations, only subgroups show a response to Sandostatin, which may be identified by scintigraphy with labeled Sandostatin. This pertains also to Graves' ophthalmopathy, for which Sandostatin may be particularly promising and where positive and negative Sandostatin scans have been demonstrated. However, for all these potential indications, larger, well-studied series are needed, before definitive conclusions can be drawn.
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PMID:Potential indications for octreotide in endocrinology. 151 41

Various drugs and hormones influence the light microscopic and especially the electron microscopic structure of the anterior pituitary and its tumors. Many structural effects are known only from animal experiments since specimens from human pituitaries are mostly not available. The structure of growth hormone (GH) cells is relatively stable. A massive GH cell hyperplasia is known only in rare cases with growth hormone releasing factor (GRF) excess from tumors. Prolactin cells can be stimulated by drugs, neurotransmitters, and hormones which decrease the dopamine inhibition. Adrenocorticotropic hormone (ACTH) cells are stimulated by stress, some hormones, loss of adrenals, and drugs which activate the alpha 1- and beta-receptors or inhibit the alpha 2-receptors. They are suppressed and changed into Crooke's cells by treatment with glucocorticoids. Thyroid-stimulating hormone (TSH) cells increase in number and size in states for overstimulation especially by thyrotropin releasing hormone (TRH). A decrease results from hyperthyroidism and possibly from somatostatin, L-dopa, and dopamine. Gonadotroph cells transform into castration cells in strongly hyperactive states (gonadectomy, antiandrogens, gonadotropin releasing hormone [Gn-RH]agonists, aminoglutethimide). Special types of pituitary adenomas can be treated with drugs which suppress hormone production and proliferation. Dopamine agonists and somatostatin reduce the tumor size of varying proportions of GH secreting adenomas in acromegaly. Ultrastructurally, a decrease of cytoplasmic and nuclear volume and an increase of lysosomes are found. Bromocriptine and other dopamine agonists are established in the treatment of prolactin secreting adenomas. They induce a shrinkage in many cases. Ultrastructurally, a reduction of cellular and nuclear size, an increase in number of secretory granules and of lysosomes, and a reduction of rough endoplasmic reticulum can be demonstrated.
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PMID:Effect of drugs on pituitary ultrastructure. 154 57

The main advances in the diagnostic evaluation of pituitary tumors and prolactinomas have been in the areas of improved magnetic resonance techniques and in the use of inferior petrosal sinus sampling. New dynamic techniques of rapid acquisition magnetic resonance imaging during bolus contrast infusion have improved the sensitivity for the diagnosis of the small microadenoma. The development of three-dimensional volume imaging has also led to a further improvement in sensitivity to small lesions of the sella. The measurement of adrenocorticotropin levels in the inferior petrosal sinus in patients with Cushing's syndrome assists in the differentiation of adrenocorticotropin-secreting pituitary tumor from other peripheral causes of the syndrome. The use of corticotropin-releasing hormone concomitant with sampling has proven to be of value in improving sensitivity and specificity. Elevated levels of growth hormone in petrosal sinus sampling have also been shown to be valuable in the early diagnosis of acromegaly when peripheral hormone levels and imaging are nondiagnostic.
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PMID:Advances in diagnostic techniques of pituitary tumors and prolactinomas. 159 Dec 82

It has been reported that paradoxical GH responses to corticotropin-releasing hormone (CRH) occur in only few patients with acromegaly. However, we have observed such responses in 7 of 14 active acromegalic patients. Therefore, we have studied the GH responses to thyrotropin-releasing hormone (TRH) (500 micrograms, iv), gonadotropin-releasing hormone (LHRH) (100 micrograms, iv) and GH-releasing hormone (GHRH) (100 micrograms, iv) in these patients to examine the relationships between the GH responses to CRH and the responses to these hypothalamic hormones. Further, these patients received human CRH (1-41) NH2 (100 micrograms, iv) with or without dexamethasone (Dex) pretreatment (1 mg/100 ml saline, iv, from -30 to +30 min) to study the mechanism of CRH-induced GH secretion, and a perifusion experiment was performed using adenoma tissue obtained at surgery from one patient (10(-7) M CRH and TRH were added) to elucidate whether CRH acts directly at the pituitary level. Aberrant GH responses induced by CRH were found in 7 of 14 (50%) acromegalic patients (TRH responders: 10/13, 77%; LHRH responders: 2/9, 22%; GHRH responders: 10/12, 83%). In these patients, percent GH increment induced by CRH ranged from 81 to 144% (Mean +/- SE, 118 +/- 8%), and the GH peak (19 +/- 3 min) appeared as early as after TRH (23 +/- 4 min, N = 10).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Plasma growth hormone (GH) responses to corticotropin-releasing hormone in patients with acromegaly--the effect of dexamethasone pretreatment and the comparison with GH responses to thyrotropin-releasing hormone, gonadotropin-releasing hormone and GH-releasing hormone. 162 75

A potent and long-acting somatostatin analogue, SMS 201-995 (SMS) is currently employed for the treatment of various diseases with hypersecretion of hormones such as acromegaly and gastrinoma. The suppressive effects of SMS are also reported on the other pituitary and gastrointestinal hormones. The corticotropic-adrenocortical axis is a crucial hormonal complex in maintaining normal activity and life itself. In this study, the effects of SMS on corticotropic-adrenocortical functions were studied, since the effects of SMS on this hormonal axis are not well established. Seven normal males received a sc injection of 100 micrograms SMS or placebo at 0830 h and 100 micrograms synthetic human corticotropin-releasing hormone (hCRH) intravenously (SMS-hCRH study). Five of the 7 subjects were given an injection of a synthetic (1-24) ACTH (250 micrograms or 63 micrograms) at 0900 h after 100 micrograms SMS or a placebo at 0830 h (SMS-ACTH study). Blood samples were drawn at -30, 0, 15, 30, 60, 90 and 120 min after the hCRH injection for the determination of ACTH and cortisol in the SMS-hCRH study, and cortisol and aldosterone in the SMS-ACTH study. Although significant rises in plasma ACTH and cortisol levels were observed regardless of the preinjection of SMS, their responses to hCRH were significantly lower with the pretreatment with SMS than without SMS. A significant increase in plasma cortisol and aldosterone was observed in response to synthetic ACTH with both ACTH alone and the combined administration of SMS and ACTH, at either dose of ACTH. However, no significant difference in cortisol and aldosterone secretion was detected with and without SMS.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of a long-acting somatostatin analogue on pituitary-adrenocortical secretion in normal human subjects. 216 54

Somatostatin analogue (Sandostatin; SMS 201-995) is utilized as a therapy in acromegaly because of its efficiency in inhibiting GH secretion; it induces some clinical improvements, such as headache remission in acromegalic patient, which seem to be unrelated to Gh normalization. We have examined 8 acromegalic patients, suffering from headache, after injection of saline solution and subsequently of SMS 201-995 (100 y), in order to study the mechanism of analgesic effect induced by Sandostatin administration. Headache, by autovaluation test, heart rate frequency, PAO, sistolic and diastolic blood velocity in medial cerebral artery, by utilizing Transcranial Doppler Sonography (SDSV), have been measured before and after saline and after SMS 201-995. GH and beta-endorphin have been also assayed in plasma samples. All patients have shown a rapid and complete improvement in headache after Sandostatin administration. At the same time we have observed an increase in SDSV and a parallel slight increase in PAO values, more evident in the diastolic phase. Plasma beta-endorphin assay has shown rather conflicting results after SMS 201-995 administration. Our results confirm an important and rapid analgesis effect of Sandostatin on acromegaly headache unrelated to GH normalization. The cerebral emodinamic changes suggest their involvement in Sandostatin induced analgesia.
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PMID:[Analgesic effect of Sandostatin (SMS 201-995) in acromegaly headache]. 227 13

In an attempt to characterize GH and PRL secretion in acromegaly, the effects of various stimuli on GH and PRL release by cultured pituitary adenoma cells derived from acromegalic patients were studied. In addition, the PRL responses of somatotroph adenoma cells were compared to those of prolactinoma cells. GH-releasing hormone-(1-44) (GHRH) consistently stimulated GH secretion in all 14 somatotroph adenomas studied in a dose-dependent manner. The sensitivity as well as the magnitude of the GH responses to GHRH were highly variable in individual tissues. Somatotroph adenomas that did not respond to dopamine were more sensitive and had greater GH responses to GHRH. In 8 of 9 somatotroph adenomas that concomitantly secreted PRL, the addition of GHRH likewise increased PRL release. Omission of extracellular Ca2+ blocked the stimulatory effect of GHRH on GH and PRL secretion. When cells were coincubated with 0.1 nM somatostatin, GH and PRL secretion induced by 10 nM GHRH were completely blocked in most adenomas. Similarly, coincubation of dopamine resulted in inhibition of GHRH-induced hormone secretion in some adenomas. Addition of TRH to the incubation medium, on the other hand, significantly stimulated GH secretion in 8 of 14 adenomas, while TRH stimulated PRL release in all of the adenomas. Vasoactive intestinal peptide (VIP) and corticotropin-releasing hormone (CRH) produced an increase in GH and PRL secretion in other adenomas. In prolactinoma cells, somatostatin and dopamine unequivocally suppressed PRL secretion; however, other stimuli including GHRH, VIP, and CRF were ineffective. TRH induced a significant increase in PRL secretion in only one prolactinoma. These results suggest that responsiveness to GHRH and somatostatin is preserved in somatotroph adenomas; the responsiveness to GHRH is inversely correlated to that to dopamine; and PRL cells associated with somatotroph adenomas possess characteristics similar to those of GH cells. Further, the GH stimulatory actions of TRH and VIP are different.
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PMID:Effects of hypophysiotropic factors on growth hormone and prolactin secretion from somatotroph adenomas in culture. 285 94

[125I-Tyr]Somatostatin [( 125I-Tyr]SRIH) binding was found in 11 GH-secreting pituitary adenomas [Kd = 0.46 +/- 0.15 (+/- SE) nM; maximum binding, 165 +/- 35 fmol/mg protein). This binding was specific, since it was displaced by somatostatin-14 (SRIH-14), N-Tyr-SRIH-14, and SRIH-28. In contrast, a number of peptides and drugs not structurally related to SRIH, such as bombesin, dopamine, LHRH, met-enkephalin, naloxone, neurotensin, secretin, substance P, TRH, or vasoactive intestinal peptide, did not affect [125I-Tyr]SRIH binding. [125I-Tyr]SRIH specific binding also was found in PRL-secreting pituitary adenomas. The kinetic characteristics of the specific binding were similar to those of GH-secreting adenomas. However, maximal binding was one quarter that of GH-secreting adenomas (37 +/- 9 fmol/mg protein). In contrast, nonsecreting (chromophobe) tumors were devoid of any specific binding. Finally, in acromegaly, the density of [125I-Tyr]SRIH-binding sites in the adenomas was negatively correlated with plasma GH levels before surgery (r = -0.80). This suggests that somatostatinergic control is involved in GH secretion in acromegalic patients.
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PMID:Somatostatin receptors in human growth hormone and prolactin-secreting pituitary adenomas. 286 Jan 20


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