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)

Effects of the 5-HT(2C/2B) receptor agonist m-chlorophenylpiperazine (mCPP) on plasma glucagon levels were investigated in rats. mCPP dose dependently increased plasma glucagon levels. Hyperglucagonemia elicited by mCPP was prevented by the 5-HT(2A/2B/2C) receptor antagonist, ritanserin, while the 5-HT(2A) receptor antagonist, ketanserin, did not show any effect. Increases in glucagon levels induced by mCPP were inhibited by prior adrenodemedullation. These results indicate that increases in plasma glucagon levels induced by mCPP are mediated by the 5-HT(2C/2B) receptor which in turn facilitates adrenaline release.
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PMID:The 5-HT(2C/2B) receptor agonist, m-chlorophenylpiperazine, increases plasma glucagon levels in rats. 1101 Oct 47

Immunostaining for chromogranin A, serotonin, glucagon and somatostatin revealed the presence of endocrine cells in 20 (35.1%) out of 57 randomly selected colorectal carcinomas. Expression of a general "neuroendocrine" marker, chromogranin A was detected in 18 tumours, whereas in the remaining two carcinomas positive reactivity with glucagon only was seen. Serotonin was expressed in 9 carcinomas, glucagon in 5 and somatostatin in 4 carcinomas. In 3 tumours coexpression of active products was found: in one--serotonin and glucagon, in another--serotonin and somatostatin, and in the last one--serotonin, glucagon and somatostatin. In 6 carcinomas expressing chromogranin A there was no expression of active products. Twelve carcinomas were assigned to a group with a small number of endocrine cells (up to 50/cm2 of tumour cross sectional area), 6 to a group with an intermediate number of endocrine cells (over 50 to 500/cm2) and 2 to a group with a large number of endocrine cells (over 500/cm2). The endocrine cells were significantly more frequent in less advanced and better differentiated carcinomas and in neoplasms with abundant mucin production. The cells were an integral part of glandular structures of the carcinoma, which argues in favour of a unitarian theory, i.e. common, endodermal origin of endocrine cells and other cellular elements of intestinal epithelium.
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PMID:Endocrine cells in colorectal carcinomas. Immunohistochemical study. 1124 95

The regional distribution and relative frequency of endocrine cells in the alimentary tract of the red-eared slider, Trachemys scripta elegans, were investigated by immunohistochemical methods using 10 antisera. Most of the immunoreactive cells in the intestine were spherical or spindle-like in shape (open-type cells), while round cells (closed-type cells) were occasionally found in the stomach. These immunoreactive cells were located in the basal portion of the intestine, including the oesophagus, and in the gastric glands of the stomach. Cg A-immunoreactive cells were restricted to the pylorus and duodenum and were few in number. Serotonin-immunoreactive cells, which were most commonly found in the pylorus, were found in the epithelia throughout the alimentary tract at various frequencies. Gastrin-immunoreactive cells were found in the pylorus, duodenum and jejunum at moderate, low and very low frequencies, respectively. Somatostatin-immunoreactive cells were found throughout the alimentary tract except for the rectum, at various frequencies. Glucagon-immunoreactive cells were detected in the fundus, pylorus, jejunum and ileum at low or very low frequencies. CCK-8-immunoreactive cells were found in the pylorus, fundus and duodenum at very low, low and moderate frequencies, respectively. Bombesin-immunoreactive cells were restricted to the fundus and pylorus at low frequencies. No secretin-, BPP- or VIP-immunoreactive cells were found in this study.
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PMID:An immunohistochemical study on the endocrine cells in the alimentary tract of the red-eared slider (Trachemys scripta elegans). 1128 61

OBJECTIVES: The distribution of serotonin (5-HT) and its effect on insulin and glucagon secretion were investigated to examine whether there are changes in the pattern of distribution and effect of 5-HT after the onset of experimental diabetes. METHODS: The pattern of 5-HT and its effect of insulin and glucagon secretion was examined using immunohistochemical and radioimmunoassay techniques, respectively. RESULTS: 5-HT was demonstrated mainly in the neural elements of the pancreas. 5-HT-containing fine varicose nerve fibers were discerned in the wall of blood vessels and pancreatic ducts. 5-HT-containing nerves were also observed in the periacinar and periinsular regions of normal pancreas. The pattern or intensity of the distribution of serotonergic nerves did not change after the onset of diabetes. The perivascular, periductal, periacinar and periinsular regions of diabetic pancreas all contained 5-HT positive nerves. 5-HT elicited marked increases in insulin secretion from normal pancreas but had an inhibitory effect on insulin secretion from diabetic pancreatic tissues. In contrast, 5HT inhibited glucagon secretion from normal pancreatic tissue fragments but stimulated glucagon release from diabetic pancreatic tissue fragments. conclusion: 5-HT is well distributed in normal and diabetic pancreatic tissues and has stimulatory effects on insulin secretion from normal pancreas and glucagon secretion from diabetic pancreas. This result indicates that although 5-HT may help in the maintenance of the blood sugar level in normal pancreas by increasing insulin secretion and decreasing glucagon secretion, it may also aggravate the hyperglycemia observed in diabetes mellitus and hence exacerbate the symptoms of hyperglycemia in poorly controlled diabetes mellitus.
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PMID:Distribution of serotonin and its effect on insulin and glucagon secretion in normal and diabetic pancreatic tissues in rat. 1146 94

We report a case of a human gastric composite tumor occurring seven years after a partial gastrectomy for a low grade B cell MALT lymphoma. Histological examination of the tumor revealed two intimately intermingled components: 1. A moderately to poorly differentiated tubulo-acinar adenocarcinoma with signet-ring cells; and 2. Isolated or clustered small neuroendocrine cells without atypia expressing chromogranin A, somatostatin and/or glucagon, serotonin (5-HT) and, the 5-HT2B receptors. In addition to immunohistochemical detection, the presence of 5-HT2B receptors was shown pharmacologically through [125I]-DOI binding. Since 5-HT2B receptors have been demonstrated to have autocrine functions and, mitogenic and transforming properties, these results suggest a role of 5-HT in neuroendocrine malignant transformation. On the other hand, the expression of somatostatin and the detection by reverse transcriptase polymerase chain reaction (RT-PCR) of somatostatin receptor subtypes 2, 3, and 5, which have been shown to be involved in tumor regression, might account for the long evolution of this case (> 5 yr). This case illustrates the importance of local humoral modulation in tumor growth. Moreover, ultrastructural results favor a unique origin of the tumor cells from one amphicrine cell type.
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PMID:Histological, immunohistochemical, ultrastructural and biochemical study of human gastric composite tumor: expression of the serotonin-2B receptor by the neuroendocrine component. 1147 72

High concentrations of glucagon-like peptide-1 (7-36) amide (GLP-1) and its specific receptor (GLP-1R) have been found in the rat hypothalamus. In this study the actions of GLP-1 and its related peptides, exendin-4 (GLP-1R agonist), exendin (9-39) (GLP-1R antagonist) and GLP-1 (9-36) amide (the major GLP-1 metabolite) on levels of serotonin (5-HT), 5-hydroxyindolacetic acid (5-HIAA) and amino acids (Glu, Asp, Gln, Gly, Tyr, Trp, GABA) in the hypothalamus were investigated. Intracerebroventricular (ICV) injection of GLP-1 (4 nmol) produced a significant reduction in levels of 5-HT (54%) and all measured amino acids (34 to 56%) compared with saline injected controls, whereas exendin (9-39) (4 nmol) was ineffective. ICV injection of exendin-4 produced a significant reduction in the levels of 5-HT, 5-HIAA, Trp, Glu, and Tyr. ICV injection of GLP-1(9-36) amide showed a statistically significant increase in the level of 5-HT, 5-HIAA and all the amino acids tested in this study. Prior administration of exendin (9-39) or GLP-1 (9-36) amide blocked the effects of GLP-1 on the levels of 5-HT and the amino acids. These data are consistent with exendin-4 being a GLP-1R agonist and exendin (9-39) being a specific GLP-1R antagonist. GLP-1 (9-36) amide, a primary metabolite of GLP-1, appears to act as an endogenous antagonist at the GLP-1R.
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PMID:Effects of intracerebroventricular injection of glucagon like peptide-1 and its related peptides on serotonin metabolism and on levels of amino acids in the rat hypothalamus. 1185 32

The regional distributions and relative frequencies of some gastrointestinal endocrine cells in the eight portions (fundus, pylorus, duodenum, jejunum, ileum, caecum, colon and rectum) of the gastrointestinal tract of SKH-1 hairless mice were investigated using immunohistochemical methods and seven types of specific antisera against somatostatin, serotonin, glucagon, cholecystokinin (CCK)-8, secretin, pancreatic polypeptide (PP) and gastrin. In this study, somatostatin-, serotonin-, glucagon-, CCK-8-, secretin- and gastrin-immunoreactive (IR) cells were identified. Most of these IR cells in the intestinal portion were generally spherical or spindle-shaped (open-type cell) while cells that were round in shape (close-type cell) were occasionally found in the stomach regions. Their relative frequencies were varied according to each portion of gastrointestinal tract. Somatostatin-IR cells were found throughout the gastrointestinal tract except for the large intestine. Serotonin-IR cells were detected throughout the whole gastrointestinal tract and were the most predominant endocrine cell types in this species of mouse. Glucagon-IR cells were restricted to the fundus, occurring rarely. CCK-8-IR cells were observed in the pylorus, duodenum and jejunum with frequencies that were numerous, moderate and few, respectively. Peculiarly, secretin-IR cells were demonstrated in the whole intestinal tract with either few or rare frequencies. Gastrin-IR cells were restricted to the pylorus and were numerous. However, no PP-IR cells were found in this study. In conclusion, some peculiar distributional patterns of gastrointestinal endocrine cells were found in SKH-1 hairless mouse.
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PMID:The regional distribution and relative frequency of gastrointestinal endocrine cells in SHK-1 hairless mice: an immunohistochemical study. 1204 43

To clarify whether scattered endocrine cells in pancreatic ductal adenocarcinoma are neoplastic or not, we immunohistochemically studied 29 cases of invasive pancreatic ductal adenocarcinomas, 17 with metastases, for chromogranin A, insulin, glucagon, pancreatic polypeptide, serotonin, gastrin, laminin, and Ki-67. Endocrine cells were found in primary sites in 24 cases (82.3%), where endocrine cells showed at least a visibly close location to adjacent islet cells. Although endocrine cells in neoplastic glands were within the neoplastic basement membrane, endocrine cells were not seen in invasive sites beyond the pancreas where islets were not present. Endocrine cells in neoplastic glands were reactive for two or three of the islet hormones in all cases, and different types of hormonal reactivity was recognized in the same neoplastic gland or the same cluster of neoplastic glands in 22 (91.7%) cases, thus suggesting a close relation with islets. Ki-67 did not stain any endocrine cells in ten of the adenocarcinomas studied. In three (10.3%) cases, endocrine cells were found in the intraductal extensions. They may have pre-existed in non-neoplastic ducts. In 17 cases with metastatic sites, all but one had no endocrine cells in the metastases. Serotonin-positive cells were found in one metastatic lymph node in one case. We concluded that most endocrine cells seen in ductal adenocarcinomas of the pancreas are non-neoplastic and are derived from the surrounding islets. Some neoplastic endocrine cells may exist, though their frequency is low.
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PMID:Immunohistochemical study of endocrine cells in ductal adenocarcinoma of the pancreas. 1224 21

Secretion of the gut hormone glucagon-like peptide-1 (GLP-1) is stimulated by meal ingestion. The response is rapid, suggesting a stimulatory pathway elicited from the upper gastrointestinal area. In pigs, we have been unable to demonstrate a neural stimulatory pathway, but GLP-1 secretion is regulated by local somatostatin secretion. In search for an endocrine pathway, we studied the effect of a range of concentrations of cholecystokinin octapeptide (26-33) (CCK 8), gastric inhibitory peptide 1-42 (GIP), secretin, motilin, calcitonin gene-related peptide (CGRP), and the modified amino acid, 5-hydroxytryptamine (serotonin, 5-HT) on GLP-1 and somatostatin release from isolated perfused segments of porcine ileum.GLP-1 secretion was stimulated by 1 nM CCK 8 and 10 nM GIP, but suppressed by 1 nM motilin and 1 microM 5-HT. Secretin and CGRP had no effect. Somatostatin secretion was stimulated by CCK 8 at 1 and 10 nM, by GIP at 1 and 10 nM and by 10 nM CGRP. Secretin, 5-HT and motilin had no effect on somatostatin secretion. We conclude that CCK 8 and GIP 1-42 stimulated GLP-1 secretion, but only in concentrations greatly exceeding normal postprandial concentrations. Thus, we find it unlikely that endocrine agents from the duodenum regulate GLP-1 secretion in pigs.
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PMID:The effects of duodenal peptides on glucagon-like peptide-1 secretion from the ileum. A duodeno--ileal loop? 1246 8

The regional distributions and relative frequencies of some gastrointestinal endocrine cells in the three portions (cecum, colon and rectum) of the large intestinal tract of C57BL/6 mice were examined with immunohistochemical method using 7 types of specific antisera against chromogranin A (CGA), serotonin, somatostatin, human pancreatic polypeptide (HPP), glucagon, gastrin and cholecyctokinin (CCK)-8. In this study, all 3 types of immunoreactive (IR) cells were identified. Most of these IR cells in the large intestinal portion were generally spherical or spindle in shape (open-typed cell) while cells with a round shape (close-typed cell) were found in the intestinal gland. Their relative frequencies varied according to each portion of the large intestinal tract. CGA-IR cells were found throughout the whole large intestinal tract but were most predominant in the colon. Serotonin-IR cells were detected throughout the whole large intestinal tract and showed highest frequency in the colon. Peculiarly, glucagon-IR cells were restricted to the colon with a low frequency. However, no somatostatin-, HPP-, gastrin- and CCK-8-IR cells were found in the large intestinal tract. In conclusion, some peculiar distributional patterns of large intestinal endocrine cells were identified in C57BL/6 mice.
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PMID:Regional distribution and relative frequency of gastrointestinal endocrine cells in large intestines of C57BL/6 mice. 1251 36


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