Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P01275 (glucagon)
 26,492 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Somatostatin (SRIF) has been tested for its actions on the central nervous system to affect glucoregulation. In doses ineffective when given systemically , SRIF and SRIF analogs given intracisternally (ic) reduce hyperglycemia and hyperglucagonemia after ic bombesin administration. The SRIF analog, des-AA1, 2, 4, 5, 12, 13-[D-Trp8]SRIF, decreases plasma insulin and elevates plasma glucose and glucagon when given systemically. However, when given ic, this peptide prevents the rise in glucose and glucagon after ic bombesin administration and is 10 times more potent than SRIF in reducing bombesin-induced hyperglycemia. Other analogs of SRIF and various unrelated peptides were found to be ineffective in reducing bombesin-induced hyperglycemia. des-AA1, 2, 4, 5, 12, 13-[D-Trp]SRIF prevented the hyperglycemia induced by surgical stress or by ic administration of beta-endorphin or carbacol. des-AA1, 2, 4, 5, 12, 13-[D-Trp]SRIF given ic did not prevent hyperglycemia induced by systemic administration of epinephrine, arginine, or glucagon. These studies suggest that SRIF and its analogs may act within the brain to affect glucoregulation.
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PMID:Somatostatin: central nervous system actions on glucoregulation. 44 91

1. A new line of cloned, differentiated rat hepatocytes (RL-PR-C) was evaluated for its usefulness as an in vitro system for studying the regulation of the insulin receptor. 2. Insulin rapidly reversibly and specifically bound to RL-PR-C hepatocytes. Binding of tracer 125I-labeled insulin, which was competitively inhibited by native insulin as well as by proinsulin and analogs of insulin and proinsulin in proportion to their biological activity, was not influenced by glucagon, corticotropin, or human growth hormone. Anti-insulin receptor serum from a patient with Acanthosis Nigricans Type B competed with 125I-labeled insulin for binding to cell surface sites. 3. Trypsinization destroyed insulin binding sites, but these were restored by incubation under growth conditions; a 75% restoration of binding sites was achieved by one cell population doubling. 4. RL-PR-C hepatocytes responded to insulin binding by an increase in glycogen synthesis from glucose. The insulin effect was maximal at 85 nM, but was detectable at lower, more physiological, concentrations. 5. Chronic exposure (for at least 3h) of hepatocytes to insulin (10(-10)--(10(-8) M) reduced by up to 60% the number of binding sites for insulin (down-regulation). Down-regulation was prevented by cycloheximide at concentration (10 micron) sufficient to inhibit markedly protein synthesis from tracer isoleucine. Recovery from down-regulation induced by native insulin at 10(-7 M or lower concentrations was complete by 18 h under growth conditions. 6. Although RL-PR-C hepatocytes spontaneously transform after about 90 population doublings, no significant differences between normal and transformed cells were observed in insulin binding characteristics and in interaction of cells with anti-insulin receptor serum. However, transformed cells exhibited a substantially reduced (maximum of 20%) down-regulation response to insulin. 7. RL-PR-C rat hepatocytes appear, for these reasons, to be a useful model system for studying the regulation of the insulin receptor.
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PMID:Hormone receptors. 7. Characteristics of insulin receptors in a new line of cloned neonatal rat hepatocytes. 56 93

Somatostatin and dihydrosomatostatin (H2somatostatin) are equipotent in inhibiting insulin and glucagon release induced by arginine in the rat. The ID50 of H2somatostatin on insulin and glucagon secretion induced by arginine are 14 +/- 6 and 6 +/- 10 mug/100 g BW respectively, similar to the ID50 of H2somatostatin (18 +/- 10 mug/100 g BW) on inhibition of insulin release induced by glucose. Thyrotropin releasing factor, luteinizing hormone releasing factor, alpha-MSH, and the N-terminus decapeptide of the beta-chain of porcine hemoglobin did not alter the secretion of insulin and glucagon induced by arginine. With the exception of [Ala2[-somatostatin and [Ala5]-somatostatin, alanine substituted analogs of somatostatin were less potent than somatostatin. [D-Trp8]-somatostatin is 6-8 times as potent as somatostatin in inhibiting insulin and glucagon release induced by arginine. The relative potencies of these analogs to inhibit the secretion of the pancreatic hormones are in good agreement with our previously reported values based on the inhibition of GH secretion in vitro.
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PMID:Biological activity of somatostatin and somatostatin analogs on inhibtion of arginine-induced insulin and glucagon release in the rat. 81 91

This investigation has been carried out on 50 samples of fetal pancreata from the 10th to the 32nd week of gestation using the PAP technique. beta-Endorphin-reactive cells were morphometrically recorded by means of the point-counting method. beta-Endorphin reactivity occurred for the first time during the 15th week. During further development, beta-endorphin cells were found inside and outside the islets. From the 18th to 23rd week, these cells were primarily localized in the islet periphery. From the 24th week, they rearranged and occurred in irregular positions mixed with other islet cells. This rearrangement took place with a 4 week delay compared with the basic cell types of the islet organ. The extrainsular portion of these cells in the exocrine parenchyma varied between 0.3% in the 27th week and up to 10% in the 22nd week. Concerning the adult human pancreas, it has been suggested whether beta-endorphin cells may be a 6th basic cell type of the islet organ. Previous studies on the coexistence of somatostatin, glucagon and beta-endorphin in the same islet cell and the morphometric analysis would support this assumption. Biochemical examinations indicate that beta-endorphin is a modulator of insulin, glucagon, and somatostatin secretion in the islet organ. This is supported by the fact that beta-endorphin cells have extended cell bodies which is typical of cells with paracrine function.
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PMID:Beta-endorphin-immunoreactive cells in the human fetal pancreas. 128 44

Minimally invasive operations such as laparoscopic cholecystectomy appear to result in more rapid recovery of normal function, less physiological disturbance, and presumably less stress to the organism than open operation counterparts. The purpose of this study was to determine the stress response associated with minimally invasive surgery compared to conventional laparotomy. Three groups of pigs underwent general endotracheal anesthesia. The first group had laparoscopic cholecystectomy, the second open cholecystectomy, and the last group (controls) had only general anesthesia. The neuroendocrine serum stress markers adrenocorticotropic hormone (ACTH), cortisol, insulin, and glucagon were measured prior to anesthesia and for the first 3 postoperative days. Analysis of the data showed significant elevations of both ACTH and cortisol for laparoscopic operations as well as for open operation (cortisol only) in the immediate postoperative period. No differences were found for the other serum stress markers. We conclude that minimally invasive surgery in this porcine model confers no advantage, as measured by four neuroendocrine stress hormones, over conventional surgery. Further study is required to determine the clinical implication of these findings.
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PMID:Neuroendocrine stress response after minimally invasive surgery in pigs. 133 96

Retinoblastoma protein (RB) is a tumor suppressor gene product involved in embryogenesis and cell cycle progression. One of the major mechanisms leading to RB dysfunction is complex formation with viral oncoproteins using the common RB binding motif Leu X Cys X Glu (LXCXE) which has also been identified in cellular ligands, e.g., RBP-1 and RBP-2. p107, a cellular protein with RB sequence homology, has been shown to bind to the same viral oncoproteins associating with RB and is therefore thought to contribute to cell cycle regulation. It has recently been suggested that insulin stimulates gene transcription through direct association with an, as yet, unidentified intracellular transcription factor. Due to the central roles of RB and p107 in coupling external growth signals with the progression of the cell cycle clock, we have hypothesized that these two proteins might be candidates for mediating the effects of insulin on DNA. We report here the identification of a region in the B-chain of human insulin that has the sequence LXCXE. Based on this finding we predict that the insulin B-chain may interact with RB and/or p107. Since we have also identified sequences hydropathically related to LXCXE in insulin-like growth factor I (IGF-I) and II (IGF-II), but not in relaxin, nerve growth factor, epidermal growth factor, glucagon or beta-endorphin, we further propose that both IGF-I and -II may assemble with RB and/or p107, too. Moreover, binding sites on RB and p107 identical with those suggested for viral oncoproteins and cellular ligands are predicted for insulin/IGF-I/IGF-II by using the hydropathic complementarity approach.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Proposed interaction between insulin and retinoblastoma protein. 133 81

The concentrations of immunoreactive (IR) corticotropin-releasing hormone (CRH) in 218 neuroendocrine tumors were determined by CRH radioimmunoassay. The tumors examined were 86 pancreatic endocrine tumors (PET), 22 neuroblastic tumors (NBT), 26 carcinoid tumors (CA), 24 pheochromocytomas (PHEO), 40 small cell lung carcinomas (SCLC) and 20 medullary thyroid carcinomas (MTC). IR-CRH was detectable in 21 neuroendocrine tumors (10 PET, four NBT, three CA, two PHEO and two SCLC) at levels of 10-2,700 ng/g wet weight (9.6%). The 21 patients with these CRH-producing tumors showed no clinical symptoms suggestive of Cushing's syndrome. The levels of plasma IR-CRH extracted by immunoaffinity chromatography were < 7.5 pg/ml in five normal subjects and a patient with a neuroblastic tumor containing 55 ng/g wet weight IR-CRH, but in a patient with a thymic carcinoid tumor containing 1,000 ng/g wet weight IR-CRH, the plasma level was elevated to 180 pg/ml. This patient did not have Cushing's syndrome nor an elevated plasma adrenocorticotropic hormone (ACTH) level. The concentrations of nine peptides (growth hormone-releasing hormone, somatostatin, ACTH, calcitonin, gastrin-releasing peptide, glucagon, vasoactive intestinal peptide, neuropeptide tyrosine and pancreatic polypeptide) were determined in extracts of the 21 IR-CRH-producing tumors. Some of these peptides were frequently found to be produced concomitantly with CRH. The results indicate IR-CRH to be produced by various neuroendocrine tumors, but Cushing's syndrome, due to the CRH, to be very rare. The results also show that CRH-producing tumors produce multiple hormones.
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PMID:Production of immunoreactive corticotropin-releasing hormone in various neuroendocrine tumors. 135 72

In a 52-year-old Caucasian man osteopoikilosis had been misdiagnosed roentgenologically 2 years before his death. Gradually he developed Cushing's syndrome and ultimately superior vena caval obstruction. At autopsy a primary thymic carcinoid with extensive osteoblastic bone metastasis was found. Immunohistochemically the tumor was shown to be positive for adrenocorticotropic hormone (ACTH), cytokeratin (KL1), neuron-specific enolase, synaptophysin, chromogranin and glucagon. Remarkably the tumour was negative for serotonin despite high urinary hydroxyindolacetic acid levels. Bilateral hyperplasia of the adrenal cortex was found. The adenohypophysis showed a considerable reduction of ACTH-producing cells and numerous Crooke's cells with a characteristic immunohistochemical pattern.
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PMID:Primary thymic carcinoid with Cushing's syndrome. 137 58

Sodium nitroprusside was infused intravenously for 10 minutes in normal men, reclining at 45 degrees, in a dose sufficient to decrease the arterial pressure by 10 mmHg. The effect on a variety of plasma hormones was measured during the infusion and for 20 minutes afterwards. The heart rate increased to a maximum of 149%. Norepinephrine rose to a maximum of 196% in 5 minutes. Epinephrine reached a peak of 207% after 10 minutes. Plasma renin activity reached a peak of 449% at 10 minutes. Aldosterone did not change during the infusion, but increased to a maximum of 145% 10 minutes later. Vasopressin increased sharply at the end of the infusion to 893% and then rapidly decreased. Corticotropin, prolactin and growth hormone started to increase toward the end of the infusion, but reached their maxima during recovery. Corticotropin (225%) and prolactin (288%) peaked 10 minutes after the infusion, while growth hormone (414%) appeared still to be rising 20 minutes after the end of the infusion. Cortisol also rose progressively during recovery to a level of 138%. No significant changes were seen in the concentrations of insulin, glucagon, atrial natriuretic peptide, bombesin or neurotensin.
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PMID:Temporal relations of the endocrine response to hypotension with sodium nitroprusside. 155 71

The thermodynamic behaviour of three peptides, bombesin, beta-endorphin and glucagon, was studied under reversed-phase high-performance liquid chromatographic conditions. Experimental data related to the interactive surface contact area (S values) and solute affinity (log k0) were derived over a range of temperatures between 5 and 85 degrees C. These experimental conditions allowed changes in the secondary structure of the solute to be monitored. The influence of the nature of the stationary phase ligand on the relative conformational stability of the three peptides was analysed by acquiring data with n-octadecyl silica (C18) and n-butyl silica (C4) sorbents. Values for the relative changes in entropy and enthalpy associated with the interactive process were also determined. The results provide further insight into the factors involved with the stabilization of secondary structure and the mechanism of the interaction of peptides with hydrophobic surfaces.
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PMID:High-performance liquid chromatography of amino acids, peptides and proteins. CXV. Thermodynamic behaviour of peptides in reversed-phase chromatography. 163 93


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