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)

Pancreastatin is a novel 49-amino acid peptide with a C-terminal glycine amide. The peptide was isolated from porcine pancreatic extracts and shows a structural similarity to chromogranin A. The effect of synthetic porcine pancreastatin on blood glucose levels and hepatic glycogen content was investigated in rats in vivo. Pancreastatin (300 pmol/kg) produced a time-dependent decrease in glycogen content of liver and a slight hyperglycemia. Basal plasma insulin and glucagon levels were not modified by pancreastatin. We suggest that pancreastatin could play a biological role in the glucose metabolism through a glycogenolytic effect.
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PMID:Glycogenolytic effect of pancreastatin in the rat. 218 44

The occurrence of transthyretin (TTR) in 25 endocrine pancreatic tumors was investigated by immunohistochemical methods using both polyclonal and monoclonal antibodies. All malignant insulinomas were strongly TTR immunoreactive, more so than their benign counterparts, which in some cases were TTR negative. All glucagonomas and nonfunctioning tumors were TTR immunoreactive, whereas gastrinomas and VIPomas were TTR negative. TTR, chromogranin A, and the argyrophil reaction (Grimelius' silver technique) had similar distributions among the cells in many, but not all, tumors. Coexistence of TTR with glucagon, insulin, or pancreatic polypeptide in tumor cells was demonstrated. TTR was also quantitated in preoperative serum samples by electroimmuno assay in some cases. Although one patient with a glucagonoma had a markedly increased serum TTR level, five other patients with endocrine tumors, including two patients with glucagonoma, had TTR levels in serum that were within or below the reference range.
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PMID:Transthyretin in endocrine pancreatic tumors. 246 44

Primary carcinoid tumours of the middle ear are extremely rare, only nine cases having been reported. However, their true incidence is probably greater, since they are very difficult or impossible to distinguish from adenomas and adenocarcinomas with conventional histological stains. We describe the clinical, histological, immunohistochemical and ultrastructural findings in a carcinoid tumour of the middle ear in a 50-year-old woman. Immunohistochemical studies on non-neoplastic middle ear mucosa undertaken to investigate the histogenesis of such tumours are also reported. Histologically, the tumour consisted of both solid areas and areas of tubular structures containing intraluminal mucus. All the tumour cells reacted with the anti-keratin antibody KL 1; some were argyrophil and reacted with antibodies against neuron-specific enolase, chromogranin A, Leu-7, serotonin, pancreatic polypeptide, glucagon and lysozyme. Electron microscopy revealed dense core granules in the tumour cells. Endocrine cells could not be detected in non-neoplastic middle ear mucosa. Pancreatic-polypeptide-like immunoreactivity was demonstrated immunohistochemically in all three other published cases of carcinoid tumour of the middle ear investigated for this peptide, and glucagon-like immunoreactivity was also exhibited by one of these. Since carcinoid tumours of the middle ear often, as in this case, exhibit some degree of glandular differentiation, immunohistochemical or electron-microscopic investigation to detect neuroendocrine differentiation is of particular importance in adenomatous middle ear neoplasms.
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PMID:Carcinoid tumour of the middle ear. A morphological and immunohistochemical study with comments on histogenesis and differential diagnosis. 248 Dec 99

In previous studies on streptozotocin-diabetic rats, transplantation of 1,000 (but not of 400) pancreatic islets to the renal subcapsular space was followed within 10 days by near-normalization of the impaired insulin secretion and the hyperglycemia. The long-term effects were now studied by measuring insulin and glucagon secretion 3 months after transplantation of 1,000 collagenase-isolated islets in streptozotocin (70 mg/kg) diabetic rats. At this time, diabetic control rats showed marked hyperglycemia and hyperglucagonemia, whereas the basal glucose and glucagon levels had normalized in the transplanted rats. Furthermore, insulin secretion in response to glucose or arginine stimulation and glucagon secretion following arginine stimulation were normal in all transplant rats, but absent in all diabetic controls. Morphologically the transplanted islets in the renal subcapsular space appeared normal on hematoxylin-eosin staining and immunostaining with antisera directed against insulin, glucagon, somatostatin and chromogranin A/B. Thus the islet transplants normalized basal hyperglycemia and hyperglucagonemia and restored insulin and glucagon secretion on a long-term basis.
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PMID:Islet transplantation to the renal subcapsular space in streptozotocin-diabetic rats. Long-term effects on insulin and glucagon secretion. 251 96

The prevalence of endocrine differentiation of conventional gastric adenocarcinoma was evaluated on the 212 cases (including 62 mucosal carcinomas) of consecutively resected stomach for adenocarcinoma in our hospital using anti-chromogranin A (CGA) antibodies. CGA-positive cells were found in 28 of 150 cases (18.7%) as an integral tumor component. In immunocytochemistry and electron microscopic examinations, we could classify these 28 cases into three groups according to the distribution patterns of CGA-positive cells. The first group consisted of 12 cases in which scattered CGA-positive cells were located in neoplastic glands. The second group consisted of six cases of scirrhous carcinoma in which CGA-positive cells were separated by fibrovascular tissue. The third group consisted of ten cases in which the positive cells were present in clusters. No definite correlation was recognized between the appearance of CGA cells and histologic types of predominance. In the analysis of the hormonal substances coexpressed by CGA-positive cells, immunoreactive serotonin (SER) was found most frequently, and somatostatin (SS), gastrin (GAS), glucagon/glicentin (GLU/GLI), and peptide-tyrosine-tyrosine (PYY) like immunoreactivities were found in a few tumor cells. CGA-positive cells occupied limited parts of the tumors in most cases, and they were noticeably more frequent in advanced stage cases. This might explain why endocrine differentiation reflects the dysexpression of the neoplastic stem cells. Furthermore, absence of mitotic figures in this type of cell and negativity of a single colony composed exclusively of CGA cells in metastatic foci suggested that these cells are in a dormant phase and are probably postmitotic.
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PMID:Endocrine differentiation of gastric adenocarcinoma. The prevalence as evaluated by immunoreactive chromogranin A and its biologic significance. 304 73

Chromogranins A and B and secretogranin II have been localized in a wide spectrum of gastroenteropancreatic endocrine/paracrine cells. Chromogranin A immunoreactivity showed the widest distribution and was displayed by glucagon-, PP-, gastrin-, gastrin-CCK-, secretin-immunoreactive cells, the most intense stainings being peculiar of enterochromaffin cells. Chromogranin B immunoreactivity was detected in gastrin- and glucagon cells and in some enterochromaffin cells containing also chromogranin A. Secretogranin II was paired to chromogranin A in glucagon cells of pancreatic islets or occurred alone in glycentin/PP cells of colonic mucosa. Neither of the chromogranins nor secretogranin II have been so far detected in somatostatin-, GIP-, or motilin-immunoreactive cells. Chromogranin A but not chromogranin B or secretogranin II has been detected in the gastric argyrophilic ECL cells.
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PMID:Chromogranins A and B and secretogranin II in hormonally identified endocrine cells of the gut and the pancreas. 322 65

Recently a new peptide, pancreastatin, was isolated from porcine pancreatic extracts. It contains 49 amino acids and shows a structural similarity to chromogranin A, which occurs in secretory granules of the endocrine pancreas. Furthermore, pancreastatin has been found to inhibit glucose-induced insulin secretion in the perfused rat pancreas. However, its effects under in vivo conditions have never been studied. We have therefore investigated the effects of this peptide on insulin and glucagon secretion in vivo in the mouse. We found that an intravenous injection of pancreastatin (4.0 nmol/kg) lowered basal plasma insulin concentration at 6 min from 55 +/- 8 microU/ml in control mice to 21 +/- 7 microU/ml (P less than .01). The peptide also inhibited the plasma insulin response to both glucose (P less than .01) and the cholinergic agonist carbachol (P less than .001). Furthermore, 2 min after injection of pancreastatin, plasma glucagon concentration had increased to 301 +/- 19 pg/ml compared to 190 +/- 12 pg/ml in control mice (P less than .001). The peptide did not, however, affect the carbachol-induced plasma glucagon response. In addition, pancreastatin induced a transient hyperglycemia. Combined adrenergic blockade by means of a pretreatment of phentolamine and propranolol did not prevent pancreastatin from exerting its effects on plasma insulin levels, whereas the increase in plasma glucagon levels was abolished. Thus, in the mouse, the newly discovered intrapancreatic peptide pancreastatin 1) lowers baseline plasma insulin levels, 2) inhibits glucose- and cholinergically induced insulin secretion, 3) stimulates baseline glucagon secretion, and 4) induces hyperglycemia.
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PMID:Pancreastatin inhibits insulin secretion and stimulates glucagon secretion in mice. 328 28

The distribution of chromogranin A and secretogranin I (chromogranin B) in normal and neoplastic human endocrine tissues was analyzed with two human monoclonal antibodies against chromogranin A, anti-bovine antiserum against chromogranin A, and an anti-rat antiserum against secretogranin I. Western blotting analyses showed both chromogranin A and secretogranin I in normal adrenals, pheochromocytomas, a pituitary adenoma, and in normal pituitary glands, but not in a bladder carcinoma. Rat adrenal medullary and anterior pituitary tissues reacted with the polyclonal chromogranin A and secretogranin I antisera, but not with the two monoclonal chromogranin A antibodies. All antibodies reacted with most of the neuroendocrine cells and tumors examined. Pituitary prolactinomas contained immunoreactive secretogranin I, but not chromogranin A. Analysis of the distribution of chromogranin A and secretogranin I in pancreatic islet cells showed that chromogranin A was found predominantly in the glucagon-producing A cells, whereas secretogranin I was present in less than 5% of islet cells. These results indicate that chromogranin A and secretogranin I are both useful in the characterization of some neuroendocrine cells and neoplasms.
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PMID:Distribution of chromogranin A and secretogranin I (chromogranin B) in neuroendocrine cells and tumors. 334 49

Secretory protein-I (SP-I) of parathyroid glands and chromogranin A ( CGA ) of adrenal medullary chromaffin cells are chemically similar if not identical proteins. Both proteins are contained within secretory granules and appear to be cosecreted with granule contents, for example, in the parathyroid with PTH and in the adrenal with epinephrine and dopamine beta-hydroxylase. Antisera to bovine SP-I and porcine CGA , together with antisera to a variety of peptide hormones, were used in an immunofluorescence study of rat tissues in order to determine the probable distribution and cellular localization of these proteins. In addition to their previously demonstrated presence in parathyroid and adrenal cells, the SP-I/ CGA protein family was detected in cells of the thyroid that contained calcitonin and often SRIF but not thyroglobulin; in cells of the anterior pituitary staining for the alpha-subunit of TSH/FSH/LH but not in cells staining for GH, PRL, ACTH, or beta-endorphin; in pancreatic islet cells staining for SRIF and pancreatic polypeptide-related peptides, but not for insulin or glucagon; in the celiac and mesenteric ganglia in cells some of which contained SRIF; and in the gastric antrum in cells containing SRIF, but not gastrin. SP-I/ CGA was not detected in cells of the liver, kidney, parotid gland, or acinar pancreas or in the intermediate or posterior lobes of the pituitary. These results suggest that this protein family enjoys a widespread but highly restricted distribution in many different endocrine-peptide cells of the rat, many that are believed to be of the APUD cell series. The possibility is raised that SP-I/ CGA plays some physiological role in the secretory process or exerts an effect of its own in the periphery after secretion.
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PMID:Selective localization of the parathyroid secretory protein-I/adrenal medulla chromogranin A protein family in a wide variety of endocrine cells of the rat. 623 31

Histological, immunocytochemical and immunofluorescence methods were employed to study the oesophagus and stomach of the elephant. The histological findings were in line with the situation in monogastric species like swine and man. In the mucosa of the stomach, endocrine cells were immunoreactive to gastrin, somatostatin, chromogranin A and serotonin. Nerve cells immunoreactive to somatostatin, bombesin, VIP, PHI and CGRP were detected in the submucosal and myenteric plexus of the stomach. In the stomach, the absence of glucagon cells and the presence of endocrine cells immunoreactive to PYY, are in contrast to the situation in mammals and need further investigation. Small gastric ulcers were observed in some of the specimens.
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PMID:The oesophagus and stomach of the African elephant: a histological, immunocytochemical and immunofluorescence study. 759 75


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