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)

Although the benign counterpart of medullary carcinoma of the thyroid has never been indicated in textbooks, we propose that C cell adenoma is a rare but distinct clinical entity. Two patients, a 43-year-old man and a 53-year-old woman, had similar thyroid tumors, both about 4 cm in diameter. The cut surfaces of the resected tumors were indistinguishable from a common microfollicular adenoma of the thyroid. Microscopically, the tumors were uniformly composed of fusiform cells without any follicle formation. Neither amyloid deposition nor calcification was found. Although some kind of C cell tumors were suggested, the exact nature was debatable. However, extremely high levels of calcitonin (1330 and 2065 pg/ml, respectively; normal level, less than 170 pg/ml) were found in the stored sera taken preoperatively. Serum levels of carcinoembryonic antigen (CEA) were normal in both patients. Immunohistochemically, the tumor tissues were positive for calcitonin and neuron-specific enolase but negative for CEA with a monoclonal anti-CEA antibody. No somatostatin, glucagon, or adrenocorticotropic hormone activity was found. It is highly probable that such tumors have not been closely studied and have been regarded as eccentric adenomas of the thyroid or simply as the so-called medullary carcinomas of the thyroid.
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PMID:C cell adenoma of the thyroid: a rare but distinct clinical entity. 319 51

A series of six ovarian strumal carcinoids was examined. The presence of thyroid follicular epithelium was conclusively proved by the presence of follicular cells immunohistochemically positive for thyroglobulin, and by the ultrastructural identification of non-neuroendocrine cells with features of thyroid epithelium lining the follicles. Progressive replacement of thyroid epithelial cells by carcinoid cells accounts for the predominance of neuroendocrine granule-containing cells and the scarcity of thyroid epithelial cells lining many of the follicles. A variety of neuroendocrine hormones and other immunoreactive substances was demonstrated within carcinoid cells, including somatostatin (five cases), chromogranin (five cases), serotonin (five cases), glucagon (four cases), insulin (two cases), and gastrin (one case). Only one case contained calcitonin-positive cells. None were carcinoembryonic antigen-positive or had amyloid deposits. The carcinoid element in five cases stained positively for prostatic acid phosphatase. While strumal carcinoid shares some features with medullary carcinoma of the thyroid gland, it has sufficient differences to warrant a separate designation.
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PMID:Strumal carcinoids of the ovary. An immunohistologic and ultrastructural study. 355 74

Twenty-seven cases of medullary carcinoma of the thyroid gland (MCT) were studied by light microscopy, immunocytochemistry, and electron microscopy. Immunoreactivity for neuron-specific enolase (NSE) and calcitonin was present in all tumors. The numbers of peptides and serotonin demonstrated in each case varied from one to eight. Bombesin was present in 18 of the 27 cases, serotonin in 15, leu-enkephalin in 8, somatostatin in 8, gastrin in 3, substance P in 1, vasoactive intestinal peptide (VIP) in 1, and ACTH in 1. Insulin and glucagon were not encountered in any of the tumors. Immunoreactivity for thyroglobulin was seen in five primary tumors as well as in one lymph node metastasis. The finding of concurrent production of calcitonin and thyroglobulin within the same tumor is enough to question the dogma of the separate origin of follicular cells and C-cells. We were unable to attach any clinical importance to the production of multiple peptides and/or amines.
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PMID:Medullary carcinoma of the thyroid gland: an immunocytochemical study. 390 54

A series of 59 thyroidal C cell neoplasms was studied by immunoperoxidase histology. These neoplasms included human medullary thyroid carcinoma and C cell hyperplasia and rat medullary thyroid carcinoma. In addition to calcitonin, the tumors were studied by immunohistology for the presence of beta-endorphin, ACTH, and somatostain. All but one of the neoplasms were positive for calcitonin, 25 of 31 were positive for beta-endorphin, 12 of 18 were positive for ACTH, and 9 of 19 were positive for somatostatin immunoreactivity. Many tissues contained all 4 peptides, and in some sections these peptide immunoreactivities seemed to be present in the same cells. These studies suggest that there is a relationship in these tumors among the 4 peptides studied, but the basis of this relationship is not clear.
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PMID:Immunohistological studies of medullary thyroid carcinoma and C cell hyperplasia. 610 48

Somatostatin-like immunoreactivity (SRIF-LI) has previously been demonstrated immunohistochemically in rat thyroid parafollicular cells. Studies were therefore performed to determine whether SRIF-LI was present in a transplantable medullary carcinoma of the thyroid (MCT) in the WAG/Rij strain of rat. SRIF-LI was found in MCT in significantly higher concentrations than in normal thyroid tissue. Thyroid and MCT SRIF-LI showed parallelism with the synthetic SRIF and RIA displacement curves and coeluted with synthetic SRIF on immunoaffinity chromatography. On gel filtration, thyroid SRIF-LI and the major peak of MCT SRIF-LI coeluted with synthetic SRIF. SRIF-LI of a larger molecular size was also present in the MCT. MCT and thyroid SRIF-LI coeluted with synthetic SRIF on high pressure liquid chromatography. MCT SRIF-LI purified by affinity chromatography was equipotent to synthetic SRIF in inhibiting dibutyryl cAMP-stimulated GH release by rat pituitary cells in monolayer culture. Serum SRIF-LI was elevated in tumor-bearing rats and showed characteristics similar to those of MCT SRIF-LI and synthetic SRIF on affinity and high pressure liquid chromatography (HPLC). Tumor-bearing rats showed diminished secretion of insulin after orally administered glucose and impaired secretion of GH in response to pentobarbital compared to normal control rats. The results indicate that SRIF-LI is produced in excessive quantities by a transplantable rat MCT and impairs the secretion of GH and insulin. The immunological, chromatographic, and biological properties of MCT SRIF-LI suggest that it is indistinguishable from synthetic SRIF.
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PMID:Somatostatin-like immunoreactivity in transplantable medullary carcinoma of rat thyroid: partial chromatographic and biological characterization. 610 40

We have examined the characteristics of circulating immunoreactive human calcitonin (IR-hCT) by studying its different molecular weight (MW) forms under various secretory conditions in a patient with medullary carcinoma of the thyroid. Plasma IR-hCT (318 mg/l basal) increased 9 and 12 times, respectively, after calcium (0 . 3 mg/kg/min over 10 min i.v.) and pentagastrin (3 . 2 microgram i.v.) administration. Somatostatin infusion (500 microgram/h) caused a 41% decrease in plasma IR-hCT and markedly diminished the responses to both pentagastrin and calcium. Sephadex G50 chromatography separated different IR-hCT forms: hCT itself predominated after stimulation with either calcium or pentagastrin (52% and 62%, respectively), while it was reduced in the basal state (33%) and following somatostatin (11%); reciprocal changes were observed for the higher MW forms. Under denaturing conditions, with or without reducing agent, total plasma IR-hCT was resolved into one major peak co-eluting with 125I-hCT. Thus, the hCT monomer appears to be the major secretory product of the medullary carcinoma of the thyroid studied here. The predominance of higher MW forms in the basal state reflects their slower plasma disappearance rate. These high MW forms are mainly the result of aggregation or non-covalent protein binding of the hCT monomer.
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PMID:Molecular weight forms of immunoreactive calcitonin in a patient with medullary carcinoma of the thyroid: dynamic studies with calcium, pentagastrin and somatostatin. 610 70

Passive immunization with somatostatin (SRIF) antiserum suggests that gastrin, glucagon, and calcitonin secretion may be exerted either locally by contiguity of SRIF-like immunoreactivity (SRIF-LI)-containing D cells and G (gastrin) and A (glucagon) cells (paracrine) or by an endocrine effect. To determine whether a reciprocal relationship exists in man between these peptides and SRIF-LI, the effects of pentagastrin (0.5 microgram/kg BW), glucagon (1 mg), and calcium (15 mg/kg BW) on serum SRIF-LI were examined. The coexistence of SRIF-LI and calcitonin in normal thyroid parafollicular C cells and medullary carcinoma of the thyroid prompted a study of the effects of the known secretagogues of calcitonin, calcium (15 mg/kg BW), and pentagastrin (0.5 microgram/kg BW) on serum SRIF-LI. Sixteen normal subjects, two patients with metastatic medullary carcinoma of the thyroid, and one patient who had undergone thyroparathyroidectomy were evaluated. We demonstrated that whereas both pentagastrin and glucagon significantly elevated serum SRIF-LI, calcium infusion had no effect. Basal and stimulated SRIF-LI levels in the normal controls, patients with medullary carcinoma of the thyroid, and the patient with thyroparathyroidectomy were similar. These results suggest that SRIF-LI secretion is related to stimulation by peptides produced in closely juxtaposed cells, that SRIF-LI, unlike calcitonin, may not be a serum marker for medullary carcinoma of the thyroid in man, and that little, if any, serum SRIF-LI originates in the thyroid.
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PMID:Pentagastrin and glucagon stimulate serum somatostatin-like immunoreactivity in man. 610 30

We have recently reported the establishment of 16 series of calcitonin-producing transplantable rat medullary thyroid carcinoma. In the present study, these tumor series have been evaluated for the presence of somatostatin-like immunoreactivity. Each of the series contained detectable levels of both peptides. Immunoreactive somatostatin varied from less than 1 ng/mg of protein to almost 500 ng/mg of protein. The range of immunoreactive calcitonin was 0.3 to 30 micrograms/mg of protein. Although somatostatin-like immunoreactivity was always less than that of calcitonin, the levels in certain series were as high as those found in neural or endocrine tissues used for in vitro studies of somatostatin elaboration. No significant correlation was found between tissue levels of these two peptides. Two tumor lines were generated by initiation of tumor growth with cells from primary monolayer cultures. Levels of both immunoreactive calcitonin and somatostatin significantly differed from those of the parent lines, which were maintained by serial passage of tissue fragments only. Plasma somatostatin-like immunoreactivity assessed in two tumor series with high (149 ng/mg of protein) and low (1.5 ng/mg of protein) tissue levels was 3100 and 50 pg/ml, respectively. Gel filtration chromatography of tissue and blood extracts showed a predominant peak (greater than 90%) of immunoreactive somatostatin eluting at the position of the native hormone. Three other peaks were resolved in the tissue extract with estimated molecular weights of 14,000, 8,700, and 5,000. The high level of somatostatin-like immunoreactivity and the presence of multiple large forms suggest that certain tumor lines will prove valuable for studies of somatostatin biosynthesis and secretion.
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PMID:Tumor and plasma somatostatin-like immunoreactivity in transplantable rat medullary thyroid carcinoma. 611 Apr 76

Somatostatin-like immunoreactivity (SLI) concentrations were determined in human peripheral plasma using affinity chromatography followed by radioimmunoassay. In normal subjects, fasting SLI ranged from 2.9 to 22.0 pg/ml with a mean +/- SE value of 10.2 +/- 2.1 pg/ml. In totally pancreatectomized or gastrectomized patients, fasting SLI levels were not different from the values in normal subjects. In patients with medullary thyroid carcinoma, fasting SLI ranged from 11.8 to 71.0 pg/ml with a mean of 29.3 +/- 12.3 pg/ml, which was significantly higher than normal values (P less than 0.01). Following meal ingestion, plasma SLI increased significantly in normal subjects from a basal level of 9.1 +/- 2.1 pg/ml to a peak value of 15.4 +/- 2.9 pg/ml (P less than 0.02). These results indicate that radioimmunoassay combined with affinity chromatography provides an accurate method of measuring SLI in human plasma.
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PMID:Somatostatin-like immunoreactivity in human peripheral plasma measured by radioimmunoassay following affinity chromatography. 611 80

Two primary neuroendocrine skin carcinomas, one bronchial carcinoma, and one typical medullary thyroid carcinoma have been shown by immunohistochemical and electron microscopy to contain two or more immunoreactive peptides as well as melanosomes and premelanosomes. Of the battery of antisera tested, somatostatin was the only material present in all four tumors; calcitonin and ACTH were present in three of the four neoplasms. Neurosecretory granules on the one hand and melanosomes on the other were more readily identifiable in separate cells. However, in at least 2 cases, individual cells were thought to contain both types of structures. Of the various explanations possible, we choose to interpret these tumors as complex neuroendocrine carcinomas comprising cellular populations capable of synchronous production of immunoreactive peptides and melanin. since melanocytes are members of the dispersed neuroendocrine (APUD) system, these observations may not appear entirely surprising. Note-worthy, however, is that melanin synthesis seemingly remains a synchronously available option to neoplastic neuroendocrine cell populations of possibly diverse histogenesis that are actively engaged in the production of multiple hormonal peptides. We consider that these phenomena represent yet another facet of neoplastic multidirectional differentiation. It is possible that the determination of immunoreactive peptides as "markers" may play a future role in the diagnosis, therapy, and prognosis of these and similar tumors and in the study of the dysplasias that may precede them.
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PMID:Neuroendocrine carcinomas with multiple immunoreactive peptides and melanin production. 611 42


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