Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P61278 (somatostatin)
 22,083 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Snell dwarf mice (dw/dw) are characterized by a genetically determined, congenital lack of pituitary GH, TSH and prolactin. Given that hypothalamic somatostatin is involved in the regulation of pituitary GH and TSH release, it was decided to investigate the content of immunoreactive somatostatin (IRS) in the median eminence of dw/dw and phenotypically normal mice of the same strain. The content of IRS in the pyloric antrum and pineal gland of these animals was also examined. The effects of ovariectomy and of hyperprolactinemia (induced by a pituitary graft under the kidney capsule) on the median eminence content of IRS were also studied in both normal and dwarf mice. Median eminence IRS content was significantly lower in the dw/dw (23.6 +/- 1.8 ng) than in normal mice (57.4 +/- 7.1 ng); no difference was found in the pyloric IRS content of dw/dw (16.9 +/- 1.6 ng/mg of protein) and normal animals (13.8 +/- 1.9 ng/mg of protein), nor in the pineal content of IRS (639.4 +/- 64.4 pg/gland in the dw/dw; 732 +/- 265 pg/gland in normals). Neither ovariectomy nor hyperprolactinemia were found to affect the IRS content in the tissues studied in normal or dwarf mice. Treatment of an additional group of 9 dwarf mice with L-thyroxine (L-T4 2 micrograms/48 h. s.c. for 2 weeks) significantly increased the animals weight (10.2 +/- 0.4 g versus 7.4 +/- 0.3 g) and produced maturation of facial features; however, it did not change the IRS content in any of the tissues studied. It is concluded that the content of IRS in the median eminence of mice with a congenital lack of GH, TSH and prolactin is significantly reduced and that this is unlikely to be related to the deficiency of thyroid hormones in these animals.
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PMID:Deficiency of immunoreactive somatostatin in the median eminence of Snell dwarf mice. 285 98

To characterize the functional aspect of prolactin (Prl) cells coexisting with corticotroph adenomas, pituitary adenoma cells obtained from a patient with Cushing's disease and a patient with Nelson's syndrome, who were associated with hyperprolactinaemia, were cultured in monolayer and their Prl responses to various secretagogues were compared with those of prolactinoma cells in culture. Immunohistochemistry performed in one of these two adenomas demonstrated the presence of Prl-containing cells in addition to ACTH cells. When ACTH-Prl adenoma cells were exposed to ovine corticotrophin-releasing factor (CRF), a dose-dependent increase in both ACTH and Prl secretion was observed, which was blocked by coincubation with hydrocortisone. In contrast, no stimulatory effect of CRF on Prl release was observed in all of the experiments using prolactinoma cells. Thyrotrophin-releasing hormone, which consistently stimulated Prl secretion in ACTH-Prl adenomas, was effective in triggering Prl release in only 25% of the prolactinomas. Exposure of the cultured cells to lysine vasopressin, growth hormone-releasing factor and vasoactive intestinal peptide resulted in an increase in ACTH and Prl secretion in one ACTH-Prl adenoma, however, none of the prolactinomas responded to these stimuli to secrete Prl. Dopamine and somatostatin, on the other hand, uniformly suppressed Prl secretion from ACTH-Prl adenomas as well as from prolactinoma cells. These results suggest that the mode of Prl secretion by mixed ACTH-Prl pituitary adenomas is not identical to that by pure prolactinomas and is, at least in part, common to that of ACTh secretion.
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PMID:Prolactin secretion by mixed ACTH-prolactin pituitary adenoma cells in culture. 285 25

We measured multiple components of serum or plasma in 221 members of a kindred with familial multiple endocrine neoplasia type 1 (FMEN1). The kindred showed typical features of FMEN1; the FMEN1 gene could be traced through 7 generations with 74 members identifiable as gene carriers. Between family screening in 1981 and completion of our study in 1985, we identified 16 previously unscreened members as carriers of the FMEN1 gene. The earliest age at diagnosis of FMEN1 was 17. The tests with the greatest yield of abnormal results among carriers of the FMEN1 gene were albumin-adjusted calcium, PTH, gastrin, and (in females) prolactin. The following tests provided little or no use in identifying carriers: prolactin (in males), pancreatic polypeptide, glucagon, glicentin, insulin, growth hormone, motilin, and somatostatin. Primary hyperparathyroidism was the commonest expression of the FMEN1 gene; the gene penetrance for this trait increased from near 0% before age 15 to near 100% after age 40. It appeared prior to development of serious morbidity from hypergastrinemia or hyperprolactinemia. All 42 co-operating members who were alive and expressing the FMEN1 gene in 1984 showed active or treated primary hyperparathyroidism. Primary hypergastrinemia had a prevalence below half of that for primary hyperparathyroidism at all ages and was not diagnosed in the absence of primary hyperparathyroidism. Primary hyperprolactinemia was still less prevalent than primary hypergastrinemia. It was limited almost exclusively to females.
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PMID:Multiple endocrine neoplasia type I: assessment of laboratory tests to screen for the gene in a large kindred. 287 98

The somatostatin analogue SMS 201-995 has recently been shown to be effective in suppressing GH secretion in most acromegalic patients. In the present study it was investigated whether PRL release in prolactinoma and acromegalic patients might also be sensitive to SMS 201-995 and whether co-secretion of PRL in acromegaly plays a role in determining the sensitivity of GH secretion to SMS 201-995. The s.c. administration of 50 micrograms SMS 201-995 did not affect high plasma PRL levels in four microprolactinoma patients. Therapy of one of these patients for 3 d with 50 micrograms three times a day also did not affect PRL levels. The single administration of 50 micrograms SMS 201-995 in 22 acromegalic patients lowered plasma GH levels for 2-6 h to less than 5 micrograms/l in 14 patients and to less than 50% of control values in 16 patients. In 18 of these 22 patients the immunohistochemical picture of the pituitary tumour was known. Eleven patients had pure GH-containing tumours and in seven patients there were mixed GH/PRL-containing tumours. In two of these latter patients there was evidence for GH and PRL being secreted by the same tumour cells. The sensitivity of GH secretion to SMS 201-995 did not differ between the patients with pure GH or mixed GH/PRL-containing adenomas. Plasma PRL levels were not affected by SMS 201-995 in the patients with pure GH-secreting tumours, but were significantly suppressed in four of the seven patients with mixed GH/PRL containing tumours. Chronic treatment for 16 weeks of one patient with a mixed GH/PRL-containing tumour with SMS 201-995 (100 micrograms three times a day) resulted in normalization of both the increased GH and PRL levels. It is concluded that SMS 201-995 does not affect tumorous PRL secretion in patients with pure prolactinomas. In acromegalic patients with mixed GH/PRL-containing tumours PRL secretion in some patients is sensitive to SMS 201-995, making these patients good candidates for chronic treatment with the analogue. The simultaneous presence of PRL in the GH-secreting pituitary tumour or the presence of hyperprolactinaemia in acromegalics does not play a role in the sensitivity of GH secretion to the somatostatin analogue.
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PMID:The sensitivity of growth hormone and prolactin secretion to the somatostatin analogue SMS 201-995 in patients with prolactinomas and acromegaly. 287 48

We report the first documentation of GHRH production by a tumour associated with proven multiple endocrine neoplasia (MEN). A 30-year-old woman had hypoglycaemia, hyperparathyroidism, and pituitary adenoma with hyperprolactinaemia. Serum growth hormone elevation was attributed to hypoglycaemia but plasma GHRH was elevated. Subtotal pancreatectomy revealed multiple endocrine tumours and nesidioblastosis. Immunohistochemistry demonstrated insulin, glucagon, and somatostatin in several tumours. GHRH was localized in the largest one and was released from that tumour in vitro. Post-operative plasma GH returned to normal. Excess secretion of humoural factors by one tumour may stimulate growth of other tumours in MEN syndromes. The prevalence of GHRH in MEN-I tumours remains to be established.
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PMID:Pancreatic endocrine tumour producing growth hormone-releasing hormone associated with multiple endocrine neoplasia type I syndrome. 288 80

The effect of somatostatin (SRIF: 10 micrograms/min during 120 min) on serum prolactin (PRL) levels was studied in eleven patients with hyperprolactinemia of varying causes: 2 patients with acromegaly; 2 with primary hypothyroidism; 4 with prolactinoma and 3 with drug (sulpiride) induced hyperprolactinemia. During SRIF infusion, no significant change in PRL levels was observed in any of the 4 groups studied except in one female patient with a prolactinoma. The biological activity of SRIF was demonstrated by the significant inhibition (P less than 0.05) of insulin levels seen in all 11 patients (52% fall in relation to basal) without simultaneous modification of glycemia. These data suggest that SRIF does not decrease PRL secretion in most patients with hyperprolactinemia.
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PMID:Absence of suppressive effect of somatostatin on prolactin levels in patients with hyperprolactinemia. 288 2

Remarkable progress has been made during recent years in the central regulation of the hypothalamic releasing and inhibiting factors and the respective anterior pituitary hormones. There are two nearly universal inhibitory organizations: short tuberoinfundibular dopamine (TIDA) neurons and somatostatinergic system originating from the periventricular hypothalamus and terminating to the median eminence. It is now known that e.g. dopamine, noradrenaline and acetylcholine enhance while 5-hydroxytryptamine and GABA inhibit somatostatin secretion. These transmitters are also involved in the regulation of all releasing factors and pituitary hormones. Clinical applications have been developed based on the regulation of prolactin and growth hormone. Inhibitory TIDA neurons are undoubtedly the major determinants of prolactin secretion. Hyperprolactinaemia is one of the most common endocrinological side-effects of the drugs antagonizing dopaminergic transmission. Expectedly, dopaminergic drugs (bromocryptine, lergotrile, piribedil, dopamine and levodopa) are quite effective in reducing high prolactin levels regardless of the reason. The secretion of growth hormone is predominantly under dual dopaminergic control: hypothalamic stimulation and pituitary inhibition. The former masters the function of the normal gland, while the peripheral inhibitory component takes over in acromegalic gland. Hence dopaminergic drugs are able to reduce elevated growth hormone levels in 30-50% of the acromegalic patients. In normal man, dopamine agonists increase growth hormone levels. An analogous situation can be seen in Cushing's disease regarding ACTH secretion.
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PMID:Aminergic regulation of neuroendocrinological functions: theoretical background and some clinical examples. 288 29

A 28-year-old woman presented with hypoglycemia and acromegaly associated with pituitary sellar enlargement. Preoperative plasma levels of insulin and growth hormone (GH) were markedly elevated and there was mild hyperprolactinemia. Laboratory tests suggested hyperparathyroidism. Partial pancreatectomy was performed and two tumors were found. Morphologic examination revealed two well-differentiated pancreatic endocrine neoplasms with distinct histologic, immunohistochemical, and ultrastructural features. Immunoreactivity for insulin was present in the larger tumor; the smaller tumor contained glucagon, gastrin, somatostatin, and pancreatic polypeptide. Both neoplasms demonstrated growth hormone-releasing hormone (GRH) immunopositivity and released GRH in vitro. Subsequent studies confirmed abnormally elevated preoperative plasma levels of GRH. Postoperatively, blood glucose, insulin, GRH, and GH normalized and there was regression of acromegalic features with significant reduction in sellar size. The clinicopathologic findings indicate that, in patients with multiple endocrine neoplasia type I (MEN-I), GRH production by pancreatic tumors can stimulate hypophysial somatotrophs resulting in GH excess and acromegaly due to a reversible pituitary lesion, most likely somatotroph hyperplasia.
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PMID:Reversible sellar enlargement due to growth hormone-releasing hormone production by pancreatic endocrine tumors in a acromegalic patient with multiple endocrine neoplasia type I syndrome. 289 85

The new data reported here, and available in the literature, are interpreted to indicate that acute release of PRL in stress is probably mediated by secretion of VIP and PHI arising from a subpopulation of paraventricular cells in the tuberoinfundibular system, and that this secretion is under serotonergic control, presumably by way of the raphe nuclear projection to the hypothalamus. The acute PRL response to suckling response is only partially under VIP/PHI control, and may be regulated by an as yet unidentified neural lobe hormone. In addition to the hypothalamic component of PRL regulation, there is a well-defined population of VIP cells within the pituitary, representing the only known example of VIP expression outside of nerve cells. This population of VIP cells is exquisitely responsive to thyroid status, and in common with the thyrotrope cell, is activated by hypothyroidism. Since VIP secretion is enhanced in the hypothyroid pituitary, and VIP release is stimulated by TRH, it is reasonable to postulate that paracrine VIP secretion may play a role in the reasonable to postulate that paracrine VIP secretion may play a role in the hyperprolactinemia prolactinemia that occurs in the hypothyroid human, although this is clearly not the case for the rat in whom hyperprolactinemia was not demonstrable. The role of VIP/PHI in human pituitary disease is unknown. We have been unable to identify any tumors that contain immunoreactive material using tissues prepared by standard methods. It may be that the demonstration of VIP/PHI is more demanding and will require better techniques for staining. The role of tuberoinfundibular VIP hypersecretion remains to be established but the evidence for stress-induced PRL hypersecretion in man encourages us to believe that at least some cases may be due to excessive hypothalamic activity. Additional potential neuroendocrine actions of VIP are in the secretomotor control of the ovary and thyroid, and in the regulation of somatostatin secretion and synthesis. In dispersed cell cultures (but not in whole hypothalamic slices from adult animals), VIP stimulates somatostatin secretion and independently stimulates the formation of somatostatin mRNA, an effect that can be duplicated in mixed cultures by treatment with forskolin, a postreceptor cAMP stimulator. In work carried out by Montminy and colleagues, the cAMP action has shown to be mediated by formation of a soluble protein that appears to activate the somatostatin gene promotor through interaction with a specific gene sequence.
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PMID:Neuroendocrine significance of vasoactive intestinal polypeptide. 289 11

The effects of human growth hormone-releasing factor (hGRF) and somatostatin on growth hormone (GH) and prolactin (PRL) secretion in perifusion of dispersed cells of human GH-secreting adenomas, obtained from seven acromegalic patients with hyperprolactinaemia, were examined. Six adenomas stained for both GH and PRL on immunohistochemical examination, and one contained only GH. GH release was consistently stimulated in a dose-dependent manner by hGRF (0.01, 0.1 and 1.0 nM) in all seven adenomas studied. PRL release was undetectable in two adenomas. In the other five, hGRF stimulated PRL release and the response was dose related. Furthermore, the PRL response was significantly correlated with the GH response to hGRF. When cells were perfused with somatostatin (1 nM), GH and PRL secretion induced by hGRF was completely antagonized. We also evaluated the effect of hGRF pretreatment on the subsequent GH response to hGRF in two adenomas. hGRF pretreatment (1 nM) for 210 min reduced the GH response to a subsequent hGRF challenge (100 nM) in one tumour but not in the other. In conclusion, the PRL response is similar to the GH response in mixed GH and PRL-secreting adenomas after exposure to GH release-stimulating and inhibiting hormones. After prolonged exposure to hGRF, some adenomas remain responsive to further stimulation with hGRF, whereas others do not.
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PMID:Growth hormone releasing factor stimulates and somatostatin inhibits prolactin release from human mixed somatotroph-lactotroph adenomas in perifusion. 290 1


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