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)

The insulin-like growth factors (IGFs) exist primarily bound to cell surface receptors or complexed to specific binding proteins (IGFBPs). The IGFBPs modulate the bioavailability of the IGFs and may enhance or inhibit IGF actions. Several distinct forms of IGFBPs have been described on the basis of size, immunological determinants, and distribution in biological fluids; the IGFBPs may differ as well in their biological function. Sheep thyroid cells produce IGFBPs under hormonal regulation. Cells grown in basal medium or with six-hormone (6H) medium supplements (transferrin, glycyl-histidyl-lysine, hydrocortisone, somatostatin, insulin, and TSH) release nonglycosylated BPs that migrate at 24, 27, 29, and 32 kDa on Western ligand blot. Cells cultured with the thyroid mitogens epidermal growth factor and phorbol ester release additional glycosylated IGFBPs of 40-44 kDa. Immunoprecipitation experiments indicate that 29- and 32-kDa IGFBPs are antigenically related to IGFBP-2, and the 40- to 44-kDa proteins are related to IGFBP-3. Using specific cDNA probes IGFBP-1, -2, and -3, we examined the regulation of IGFBP mRNA levels in sheep thyroid cultures. The rat IGFBP-2 cDNA probe hybridized to an approximately 1.6-kilobase mRNA species in cells under all culture conditions. However, IGFBP-3 mRNA was detectable only in epidermal growth factor- or phorbol ester-treated cells and appeared within 4 h, preceding the release of IGFBP-3 protein into the medium. The 6H additives, which stimulate differentiated function in thyroid cells, inhibited the mRNA levels of both IGFBP-2 and IGFBP-3. IGFBP-1 mRNA was not detectable. The distinct regulation of these IGFBPs suggest that they may play different biological roles in modulating thyroid physiology.
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PMID:Regulation of insulin-like growth factor-binding protein messenger ribonucleic acid levels in sheep thyroid cells. 170 62

Six insulin-like growth factor binding proteins (IGFBP) have been identified in the conditioned medium from sheep thyroid cells cultured under serum-free conditions. IGFBPs of 32, 28, 23 and 19 kDa were secreted by cells cultured for 14 days in serum-free and hormone-free medium. The constitutive secretion of IGFBP was inhibited by thyrotropin (TSH, 0.3 mU per mL). The effect was most marked on the secretion of the 28 kDa BP. High insulin concentrations stimulated the secretion of this IGFBP. The stimulatory effects of insulin were inhibited by TSH. Growth hormone treatment decreased the secretion of the 28 kDa protein. Tetradecanoylphorbol-13 acetate (TPA) and epidermal growth factor (EGF) both of which stimulate thyroid cell growth but inhibit differentiated function, markedly stimulated IGFBP secretion and induced the appearance of a 46 and a 150 kDa IGFBP. The effects of EGF and TPA were not identical. A rat IGFBP-2 cDNA reacted with sheep thyroid RNA of approximate size 1.6 kb. TPA treatment increased IGFBP-2 mRNA. Other hormones used to enhance differentiation and growth in thyroid cells in culture i.e. transferrin, somatostatin, cortisol and glycyl-histidyl-lysine acetate had no marked effects on IGFBP secretion nor on TSH-dependent, insulin-mediated iodide uptake and organification and cell growth. We show a correlation between secretion of high molecular weight IGFBP with enhanced growth but decreased function. Conversely, we find a correlation between decreased secretion of the 28 kDa BP and increased growth and function.
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PMID:Thyrotropin inhibits while insulin, epidermal growth factor and tetradecanoyl phorbol acetate stimulate insulin-like growth factor binding protein secretion from sheep thyroid cells. 172 84

A serum-free culture medium (defined medium = DM) was elaborated by adding to Eagle's minimum essential medium (MEM), non-essential amino acids, transferrin, putrescine, tripeptide glycyl-histidyl-lysine, somatostatin, sodium selenite, ethanolamine, phosphoethanolamine, sodium pyruvate, and metal trace elements. This medium was tested for its ability to support sustained surfactant biosynthesis in fetal alveolar epithelial type II cells. For up to 8 days, ultrastructure was maintained with persistence of lamellar inclusion bodies. Thymidine incorporation into DNA was enhanced about 50% in DM as compared with MEM, whereas it was enhanced 300% in 10% fetal bovine serum. With DM, the incorporation of tritiated choline into phosphatidylcholine (PC) of isolated surfactant material was about twice that with MEM. Deletion experiments evidenced the prominent role of pyruvate, transferrin, and selenium in the stimulation of surfactant PC biosynthesis. The addition of biotin to DM enhanced surfactant PC biosynthesis slightly and nonsurfactant PC biosynthesis markedly. The presence of nucleosides seemed unfavorable to the synthesis of surfactant PC. Type II cells responded to the addition of epidermal growth factor and insulinlike growth factor-I both by increased thymidine incorporation into DNA and choline incorporation into PC. It is concluded that DM represents a useful tool for cultivating type II cells without loss of their specialized properties and for studying the regulation of cell proliferation and surfactant biosynthesis in a controlled environment.
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PMID:Culture of fetal alveolar epithelial type II cells in serum-free medium. 174 24

A relationship between blood plasma levels of polypeptide growth factors and those of peptide and sex steroid hormones, as assayed radioimmunologically, was studied in 91 patients with bone tumors of various histology and 45 healthy donors. The levels of insulin-like growth factor (IGF-1) and somatotropic hormone were significantly higher in cases of chondrosarcoma and patients suffering osteogenic sarcoma in the late puberal period as compared to controls and cases of fibrous histiocytoma, giant-cell tumor, benign tumors and tumor-like lesions of the bone. The peak levels of IGF-1, somatotropic hormone and insulin were registered in osteogenic sarcoma patients who developed pulmonary metastases either in the course or after the completion of combined treatment. Somatostatin level was significantly lower in patients with osteogenic sarcoma aged 11-20 years as compared to healthy adolescents, the lowest level being observed in adolescents suffering osteogenic sarcoma with metastases to the lungs. No relationship was established between total testosterone level, on the one hand, and those of IGF-1 and epidermal growth factor, on the other. A reverse correlation was established between concentrations of IGF-1 and total estradiol. The role of polypeptide growth factor antagonists in combined treatment of bone sarcomas is discussed.
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PMID:[Polypeptide growth factors and their interrelation with hormones in the blood plasma of patients with primary bone tumors]. 184 44

This article emphasizes and reviews the premise that because the pathogenesis of acute gastric mucosal injury is multifactorial, several protective mechanisms should also be considered in analyzing gastric mucosal defense. The first part of the article reviews the pathogenesis of acute gastric mucosal injury by major etiologic factors such as hypoxia and chemical and biological agents, and emphasizes the common endogenous mediators of damage (e.g, endothelins, leukotrienes, thromboxane, platelet-activating factor, monoamines, free radicals, proteases, ammonia, hydrochloric acid, and bile acids--in decreasing potency). The second part of the review is devoted to the gastroprotective mechanisms that are analyzed by anatomical (histologic) location and biochemical processes. The endogenous mediators of acute gastroprotection include prostaglandins, sulfhydryl (SH) compounds, non-SH antioxidants, polyamines, and epidermal growth factor, whereas the protective and mediatory role of glucocorticoids, somatostatin, pentagastrin, histamine, gangliosides, and calcitonin gene-related peptide need further studies. A list of endogenous and exogenous chemicals that exert biphasic, damaging, and protective effects on the gastric mucosa in also included. The final common pathway of acute gastroprotection at the structural and functional level seems to be the preservation of subepithelial microvascular integrity leading to maintenance of mucosal blood flow that allows the energy-dependent rapid restitution (cell migration) from surviving gastric neck cells to repair the superficial epithelial defect. Very new data on the contribution of a histodilutional barrier and release of proteases to gastroprotective processes are also discussed.
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PMID:Mechanisms of gastric mucosal injury and protection. 188

The effects of treatment with a somatostatin analog (Sandostatin, SMS201-995) were investigated in female rats with dimethylbenzanthracene (DMBA)-induced rat mammary tumors. A 3-week treatment was performed using sandostatin, the LHRH-agonist buserelin alone, or buserelin in combination with sandostatin. Twice daily sandostatin treatment was performed with dosages of 0.05 microgram, 0.2 microgram, 1 microgram, 5 micrograms, and 20 micrograms. Buserelin was used in a 2 x 5 micrograms/day dosage. The combined results from six different experiments show that the various dosages of sandostatin caused no tumor growth inhibition. Somatostatin receptors could not be demonstrated in these mammary tumors. Sandostatin treatment by daily injections did not suppress levels of growth hormone, prolactin, or epidermal growth factor-like activities. Estrogen (ER) and progesterone (PgR) receptor contents of the mammary tumors were not changed. In contrast, buserelin treatment caused highly significant tumor remission. The combined treatment with sandostatin and buserelin did not alter the treatment results obtained after treatment with buserelin alone. In conclusion, sandostatin treatment in this tumor model had no direct growth inhibitory effect and did not cause an endocrine inhibition of mammary tumor growth. However, these results do not exclude antitumor effects in human breast cancer in view of the presence of somatostatin receptors in approximately 20-45% of human tumors, besides possible different endocrine effects.
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PMID:The somatostatin analog Sandostatin (SMS201-995) in treatment of DMBA-induced rat mammary tumors. 196 5

Sixteen primary human lung tumours were analysed for their content of somatostatin receptors using receptor autoradiography with somatostatin-28 and somatostatin octapeptide analogues as radio-ligands. Two out of 4 small-cell lung carcinomas were somatostatin receptor-positive, with a high density of homogeneously distributed receptors on tumour tissue only. Somatostatin receptors were characterized in one of the tumours in homogenate binding assay as saturable, high-affinity binding sites (KD = 0.53 nM) with a number of sites (Bmax) equivalent to 189 fmoles/mg protein. These sites were specific for somatostatin, since only biologically active somatostatin analogues but not unrelated peptides showed high-affinity binding. Both receptor-positive patients had limited disease; furthermore, the small-cell lung carcinoma patient with the longest survival was receptor-positive, while the one with the shortest survival was receptor-negative. None of the 12 non-small-cell lung carcinomas (5 squamous carcinomas, 7 adenocarcinomas) contained somatostatin receptors. For comparison, epidermal growth factor receptors were found in all non-small-cell lung carcinomas. Neuroendocrine features (synaptophysin, chromogranin, neuron-specific enolase, protein gene product 9.5) were present in all small-cell lung carcinomas but absent in non-small-cell lung carcinomas. Given the receptor-mediated action of somatostatin in other neuroendocrine tumours, these data may have a bearing on the clinical application of somatostatin analogues in patients with small-cell lung carcinomas.
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PMID:Somatostatin receptors are present in small-cell but not in non-small-cell primary lung carcinomas: relationship to EGF-receptors. 196 52

The aim of the present study has been to examine the effects of various concentrations of somatostatin (SS), epidermal growth factor (EGF), as well as of interactions among SS, EGF and thyrotropin (TSH) in their influence upon the mitotic activity of thyroid follicular cells (TFC) in organ culture. The stathmokinetic method was employed. It was shown that: (1) SS, at the concentration of 10(-7) M, suppressed the mitogenic effect of TSH, as well as of TSH and EGF employed together, on TFC; (2) EGF, at the concentration of 10 and 100 ng/ml, increased the mean mitotic activity rate of TFC; (3) TSH and EGF revealed an additive action on TFC proliferation. The obtained results evidently suggest an antiproliferative effect of SS and mitogenic action of EGF on TFC in organ culture.
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PMID:Influence of somatostatin and epidermal growth factor (EGF) on the proliferation of thyroid follicular cells in organ culture. 197 80

A sensitive radioimmunoassay was developed for human epidermal growth factor (hEGF) in saliva and gastric juice. This method was sufficiently sensitive for an accurate measurement of hEGF in these biological fluids. The minimal detectable concentration of EGF was 30 ng/L. The imprecision profile of EGF standard curve had a CV less than 10% in the range of 0.1-3.0 micrograms/L. Serial dilution curves of saliva and gastric juice paralleled that of standard EGF. The antibody to hEGF showed no cross-reactivity with a large excess of growth factors, such as human transforming growth factor alpha, human insulin-like growth factor I, and platelet-derived growth factor (c-sis). No detectable cross-reactivity was observed with some biological gut peptides: somatostatin, gastrin, secretin or pancreatic polypeptide. The intra-assay CV for saliva and gastric juice was less than 10%, and the recoveries were 93.9 +/- 8.7% and 93.7 +/- 11.3%, respectively for saliva and gastric juice. Gel exclusion chromatography revealed hEGF-like substances, heterogeneous in size in saliva and gastric juice, the origins and physiological functions of which are unknown.
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PMID:Radioimmunoassay of epidermal growth factor in human saliva and gastric juice. 204 84

In view of advancements in treatment of certain hormone-dependent cancers with analogues of luteinizing hormone-releasing hormone (LH-RH), this study was undertaken to establish the presence and characteristics of receptors for [D-Trp6]LH-RH on the membranes of human endometrial cancer. Specific binding of [125I,D-Trp6]LH-RH was demonstrated in membrane preparations from 24 of 31 (77%) endometrial carcinomas and from 3 of 13 (23.1%) nonmalignant human endometrial specimens. Ligand binding was dependent on temperature, time, and plasma membrane concentration in a fashion expected of a peptide hormone. Mathematical analysis of the binding data showed that interaction of [125I,D-Trp6]LH-RH with the binding sites was consistent with the presence of a single class of high affinity, noncooperative receptors (Kd 9.88 +/- 4.59 x 10(-9) M; Bmax 0.70 +/- 0.14 x 10(-12) mol/mg membrane protein). The rates of association and dissociation were calculated to be 6.5 x 10(6) M-1 min-1 and 0.021 min-1, respectively. [125I,D-Trp6]LH-RH binding was not displaced by either unlabeled somatostatin or epidermal growth factor, but was displaced completely by native LH-RH. Using 125I-epidermal growth factor, specific, high-affinity receptors were also detected in membranes from 22 of 26 (85%) endometrial cancers and in all of 6 nonmalignant endometrial specimens (Kd 0.42 +/- 0.12 x 10(-9) M; Bmax 0.30 +/- 0.15 x 10(-12) mol/mg membrane protein). The potential functional role of the receptors for [D-Trp6]LH-RH in human endometrial carcinoma is not clear, but this finding provides a rationale for the use of therapeutic approaches based on LH-RH analogues in this malignancy.
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PMID:Detection and partial characterization of receptors for [D-Trp6]-luteinizing hormone-releasing hormone and epidermal growth factor in human endometrial carcinoma. 215 60


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