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)

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

A comparison was made with the data of 62 cases of pituitary adenoma, evaluated pre- and postoperatively, including as well the results of immunohistochemical hormone examination (also for calcitonin). Prolactin was found in 18 of the 21 adenomas carrying the preoperative diagnosis of prolactinoma, whereas cells containing other hormones (growth hormone, LH, FSH, TSH, ACTH, beta-endorphin), were only occasionally present. The growth hormone was strongly positive in the adenoma tissue in 16 of the 17 cases of acromegaly. 5 of these adenomas were accompanied by a marked hyperprolactinemia and also contained many prolactin cells. 6 of the 19 adenomas diagnosed as being 'inactive' contained hormone-positive cells, but only a very small number of cells. ACTH was found in 3 of the 4 pituitary adenomas of patients with Cushing's disease. 2 of these were also positive for beta-endorphin. The tissue of 1 gonadotrophic adenoma (with elevated FSH in serum) gave positive results with an anti-LH antiserum. Calcitonin was not found in any adenoma. The preoperative serum prolactin levels did not quantitatively correlate with the percentage of prolactin-positive cells.
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PMID:Immunohistochemical examination of pituitary adenomas. Comparison to clinical and endocrinological findings. 298 43

Two patients with ectopic pituitary adenomas and biopsy-proven normal anterior pituitaries are described. Both tumors were located in the sphenoid sinus. One tumor produced prolactin, and the other one was a plurihormonal adenoma that produced predominantly adrenocorticotropin and to a lesser extent thyroid stimulating hormone and alpha subunit. The patient with the plurihormonal tumor, who had Cushing's disease, was cured by surgery while the patient with the prolactinoma was treated by surgery and medical therapy. A review of these two cases and an additional nine cases from the literature of ectopic pituitary adenomas in patients with normal intrasellar anterior pituitaries indicate that these uncommon tumors are capable of secretory function and may be the only cause of excessive pituitary hormone production.
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PMID:Ectopic pituitary adenomas with normal anterior pituitary glands. 301 37

The frequency of detection of serum antibodies against pituitary cells was determined in 32 patients with the primary empty sella syndrome. Antibodies reacting with corticotropin-secreting mouse AtT20 and PRL-secreting rat GH3 cells were found in 24 (75%) and 15 (47%), respectively, of the 32 patients; 14 patients (44%) had antibodies reacting with both cell lines. In patients with pituitary adenomas, the prevalence of antipituitary antibodies was significantly lower than in those with the empty sella syndrome; 1 of 9 acromegalic patients had antibodies reacting with GH3 cells, and 2 of 9 prolactinoma patients and 1 of 7 patients with nonfunctioning adenomas had antibodies reacting with both AtT20 and GH3 cells. Among 6 patients with idiopathic diabetes insipidus, 1 patient had antibodies reacting with AtT20 and GH3 cells, and 2 patients had antibodies reacting with either AtT20 or GH3 cells. None of 5 patients with established autoimmune diseases (3 with systemic lupus erythematosus and 2 with autoimmune adrenal failure) had antipituitary antibodies in their serum. These results suggest that pituitary antibodies may be related to the development of pituitary atrophy and the primary empty sella syndrome, and that the test may be clinically useful as a screening test for the empty sella syndrome.
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PMID:Antipituitary antibodies in patients with the primary empty sella syndrome. 341 43

A 33-year-old male was admitted to the Department of Neurosurgery, Fukui Medical School with a complaint of headache. There were no neurological deficits on admission. Craniogram demonstrated a so-called "phantom sella". A computed tomography revealed a high density mass lesion and the mass was enhanced well, that mainly extended from the sella to the left middle cranial fossa. The left carotid angiogram revealed an avascular mass lesion extending from the sella to the left middle cranial fossa. Pituitary function tests revealed an extremely high serum prolactin (PRL) levels (70, 100 ng/ml). PRL response to TRH was delayed in peak and the high level continued. Serum PRL levels elevated to 90, 800 ng/ml at 180 min after injection of TRH. A biphasic response was demonstrated in response to CB-154 suppression test to PRL secretion, that is, CB-154 stimulated PRL release initially (up to 90 min) and suppressed thereafter. Serum PRL levels (178, 400 ng/ml) reached to peak about 90 min after CB-154 administration. Response of growth hormone (GH) and adrenocorticotropic hormone (ACTH) to insulin were also impaired. Craniotomy was performed. The tumor was partially removed and was diagnosed as a prolactinoma histologically. Tumor tissue removed was subjected to the monolayer culture and electron microscopic study. Their observations demonstrated hyperactive PRL secretion of the individual cells. A total dose of 5,000 rads was irradiated postoperatively.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[A case of male prolactinoma presenting extremely high serum prolactin levels and biphasic response to CB-154 suppression test]. 404 Dec 91

Previous series of pediatric pituitary adenomas have been small and have not been analyzed by age group. We analyzed the frequency, manifestation, course, and biology of these tumors before, during, and after puberty in 136 children younger than 20 years old at surgery, identified by review of 2230 patients treated from 1969 to 1993. Tumors were classified by clinical phenotype. Adrenocorticotropic hormone-releasing adenomas were most common before puberty, and prolactinomas were most common during and after. The frequencies of adrenocorticotropic hormone-releasing adenomas, prolactinomas, and endocrine-inactive adenomas differed from those in adults. Growth arrest was common with all types except growth hormone (GH)-releasing adenomas; menstrual irregularities were common with all but adenomas causing Nelson syndrome. Among girls with prolactinomas, the preoperative duration of primary amenorrhea was longer than that of other symptoms. Tumor size differed by adenoma type. Serum hormone levels shortly after surgery correlated with the recurrence of prolactinomas and GH-releasing adenomas. The prolactinoma size correlated with the maximum preoperative serum prolactin level; boys had larger tumors and higher preoperative and postoperative prolactin levels. We conclude that pediatric pituitary adenomas vary in size, age at symptom onset, and frequency before, during, and after puberty. Most adenomas can cause menstrual irregularities, and primary amenorrhea should prompt investigation of the sella. Growth arrest is common with all adenomas except GH-releasing adenomas. Serum prolactin and GH levels measured at 1 to 5 days after surgery indicate the risk of recurrence of prolactinomas and GH-releasing adenomas, respectively.
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PMID:Pediatric pituitary adenomas. 773 5

The authors have reviewed the results of transsphenoidal surgery for pituitary adenomas done on 66 children (younger than 16 yr of age) between 1966 and 1992. Ninety-four percent (62 of 66) showed clinical evidence of pituitary hormonal hypersecretion. The most common type was the adrenocorticotropic hormone-secreting adenoma (n = 36), followed by the prolactinoma (n = 18) and the growth hormone-secreting types (n = 8). There were four cases of nonfunctioning adenomas. Adrenocorticotropic hormone-secreting tumors in children had presentations and surgical results similar to those seen in adults. Twenty-three of 33 patients with Cushing's disease had simple adenomectomy or subtotal hypophysectomy without symptomatic recurrence. Four of 10 initial treatment failures had subsequent successful surgical intervention, resulting in an overall cure rate of 78%. Postoperative hypocortisolism was suggestive of surgical success but was not absolute. Of three patients with Nelson syndrome, none were successfully treated with surgery alone and two developed invasive disease. Prolactin-secreting and growth hormone-secreting tumors in children occurred more commonly with suprasellar expansion than did their adult counterparts. Transsphenoidal surgery was capable of controlling disease in only 12% (1 of 8) of growth hormone-secreting tumors, and 67% (12 of 18) of prolactin-secreting tumors required postoperative medical therapy or radiotherapy for persistently elevated prolactin levels. Special difficulty was noted in boys with prolactinomas and in girls with primary amenorrhea. As in adults, preoperative prolactin levels correlated with ultimate surgical success rates.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Transsphenoidal surgery for pituitary adenomas in children. 817 79

The effects of surgery on pituitary-gonadal function were investigated in women with pituitary adenomas other than prolactinomas. The subjects were 46 women of premenopausal age with a pituitary adenoma. Twenty tumors were GH producing, 19 were nonfunctioning, and 7 were adrenocorticotropin producing adenomas. The surgery was performed mainly via the transsphenoidal route, with the aim of eradicating the tumor and preserving pituitary function. The menstrual cycle was preserved postoperatively in 9 out of 10 (90%) patients with regular preoperative menstruation. Menstrual disturbance was seen in 36 (78.3%) cases preoperatively. The causative factors for menstrual disturbance were gonadotropin impairment and hyperprolactinemia in GH producing and nonfunctioning adenoma. Excessive hormonal secretion itself is a major causative factor for menstrual disturbance in GH and ACTH producing adenoma. Regular menstruation was restored following surgery in 20 out of 36 (55.6%) patients with menstrual problems. The predicting factors for postoperative recovery of menstruation are: size of adenoma less than 40 mm, period of amenorrhea less than 5 years, and preoperatively preserved gonadotropin secretion. In addition, preoperative hyperprolactinemia was also a predicting factor in women with nonfunctioning adenoma. Thus, even in patients with pituitary adenomas other than prolactinoma, the restoration of menstruation is highly achievable when surgery is performed with attention to preserving pituitary function.
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PMID:Effect of surgery on gonadal function of premenopausal women with pituitary adenomas other than prolactinomas. 879 26

Based on the facts that prolactin and adrenocorticotropic hormone (ACTH) each seem to influence the secretion of the other, that dopamine is the established inhibitory factor for prolactin secretion and negatively modulates ACTH release, and finally that alterations of the central dopaminergic tone have been postulated in tumorous hyperprolactinemia, we studied the effects of pharmacological manipulations of the dopaminergic system on ACTH and cortisol secretion in patients bearing a prolactinoma and in normal subjects. Twenty-seven patients with a prolactin-secreting pituitary tumor and 12 healthy controls were submitted to three tests: (a) 4-h saline infusion; (b) 10 mg metoclopramide (MTC) as an intravenous bolus after a 2-h saline infusion; and (c) 4-h dopamine infusion at the dose of 0.01 microgram/kg/min with a 10-mg intravenous bolus of MTC given at the second hour of dopamine infusion. Administration of MTC, compared to saline, caused a moderate (not significant) plasma ACTH increase, and a significant cortisol increase (p < 0.05), both in hyperprolactinemic and normal subjects, without statistically significant differences between the two group. When MTC was administered during dopamine infusion, the ACTH and cortisol elevation was significantly potentiated in prolactinoma patients while it was similar in magnitude to that recorded after MTC alone in control subjects. These findings support the concept of an inhibitory role exerted by dopamine and are compatible with a stimulatory influence exerted by prolactin on corticotropin-releasing hormone and ACTH secretion, and also favor the view of a reduced central dopaminergic tone in patients with tumorous hyperprolactinemia.
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PMID:Dopamine infusion enhances the adrenocorticotropic hormone and cortisol response to metoclopramide in hyperprolactinemic patients but not in normal subjects. 920 95

We reviewed the clinical features, essential laboratory data, pituitary imaging findings (computerized tomography and magnetic resonance imaging), management, and outcome of 353 consecutive patients with the presumptive diagnosis of pituitary tumor investigated from January 1984 through December 1997 at University Hospital, Lausanne, Switzerland. In 18 cases primary empty sella turcica was diagnosed, and in 13 cases of pseudacromegaly there were no endocrine abnormalities. The remaining 322 patients disclosed abnormal pituitary masses, including 275 pituitary adenomas, 18 craniopharyngiomas, 6 cases of primary pituitary hyperplasia, 6 intrasellar meningiomas, 6 cases of distant metastases, 4 intrasellar cysts, 2 chordomas, 1 primary lymphoma, and 1 astrocytoma. Biologic data and immunohistochemical analysis of the excised tissues demonstrated that prolactinomas and nonsecreting adenomas (NSAs) were the most frequent pituitary tumors (40% and 39%, respectively), followed by somatotropic adenomas with acromegaly (11%) and Cushing disease (6%). In contrast with the vast majority of NSAs, which significantly expressed glycoprotein hormones in tissue without secreting them, there was a small group of glycoprotein hormone-secreting adenomas (2%), which had a more severe clinical course after surgery. Thirty-eight pituitary masses were incidentally discovered, most of them NSAs. The expansion of pituitary adenomas into the right cavernous sinus was twice as frequent as to the left cavernous sinus. For the differential diagnosis of hyperprolactinemia, basal prolactin (PRL) levels above 85 micrograms/L, in the absence of renal failure and PRL-enhancing drugs, and a PRL increment of less than 30% after thyrotropin-releasing hormone (TRH) accurately ruled out functional hyperprolactinemia due to NSA, and were typical of prolactinomas. For screening and follow-up of acromegaly, basal growth hormone (GH) and insulin-like growth factor 1 (IGF-1) levels, as well as the paradoxical GH response to TRH (present in 2/3 acromegalic patients), could be used as convenient tools, but the most accurate test for diagnosis and prediction of outcome after therapy was GH (lack of) suppression during oral glucose tolerance test. In Cushing disease, single evening plasma cortisol was as good as the overnight dexamethasone suppression test for screening, and a combined dexamethasoneovine corticotropin-releasing hormone (oCRH) test was as accurate as the long dexamethasone suppression test to confirm the diagnosis. Bilateral inferior petrosal sinus catheterization coupled with oCRH test confirmed the pituitary origin of excess adrenocorticotropic hormone (ACTH) in all patients, including those with normal pituitary on magnetic resonance imaging (50% of the cases). However, this procedure failed to predict tumor localization correctly within the pituitary in 21% of patients. Pituitary cysts, meningiomas, and craniopharyngiomas with an intrasellar component were correctly diagnosed based on pituitary imaging in 75%, 67%, and 44% of cases, respectively. The remainder, as well as the cases of pituitary hyperplasia, metastases, and other less frequent pathologies, were initially diagnosed as NSAs or as masses of unknown nature. When surgery was indicated, pituitary adenomas and other intrasellar masses were operated on by the transsphenoidal route, with the exception of 100% of meningiomas, 83% of craniopharyngiomas, and 10% of NSAs, which were operated on by the transcranial route. Favorable late surgical outcome of prolactinomas could be predicted by a restored PRL response to TRH. However, dopamine agonist (DA) therapy, usually resulting in satisfactory control of PRL levels and in tumor shrinkage, progressively displaced surgery as primary treatment for prolactinomas throughout the study period. After full-term pregnancy, the size of prolactinoma decreased in 7 of 9 patients, and PRL was normal in 2. Surgery was the first treatment for NSAs, with a tumor rela
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PMID:Diagnosis, treatment, and outcome of pituitary tumors and other abnormal intrasellar masses. Retrospective analysis of 353 patients. 1042 6


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