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

The release of pancreatic polypeptide (PP) by gut hormones, acetyl choline and adrenaline was investigated in an isolated perfused pancreas preparation. PP was potently released by 1 nmol/1 caerulein (186 +/- 12%, p is less than 0.001) and gastric inhibitory peptide (GIP) (211 +/- 31%, p is less than 0.005) as well as by 1 mumol/1 acetyl choline (1097 +/- 59%, p is less than 0.001). A significant two-fold release of PP was also evoked by 1 nmol/1 vasoactive intestinal peptide (VIP) (129 +/- 38%, p is less than 0.02 and gastrin (108 +/- 25% p is less than 0.01). Insulin release, induced by high glucose concentration was enhanced by both GIP (210 +/- 38%, p is less than (0.01) and VIP (48 +/- 5%, p is less than 0.001). In addition GIP enhanced the release of glucagon by 179 +/- 18% (p is less 0.001) at 1.4 mmol/1 glucose and by 127 +/- 24% (p is less than 0.005) at 8.3 mmol/1 glucose. Thus no simple inter-relationship appears to exist between the control of the three circulating islet hormones.
 ...
PMID:Pancreatic polypeptide, glucagon and insulin secretion from the isolated perfused canine pancreas. 66 4

A radioimmunoassay for the measurement of gastric inhibitory polypeptide (GIP) in unextracted plasma in man has been developed using a rabbit antiserum raised against porcine GIP. Porcine GIP was employed also as standard and to produce a 125I-labelled tracer. The assay was able to distinguish 110 pg/ml GIP from zero in plasma samples. Negligible cross-reactivity was demonstrated with cholecystokinin, insulin, pancreatic polypeptide, glucagon, secretin, and vasoactive intestinal polypeptide. The mean overnight fasting plasma GIP level in 28 normal subjects was 203 pg/ml (range: undetectable--420 pg/ml). Plasma GIP levels rose, within 45 minutes of eating a mixed meal, to a mean level of 1573 pg/ml.
 ...
PMID:Radioimmunoassay of gastric inhibitory polypeptide. 67 95

1. The mechanisms of release of pancreatic glucagon, insulin and pancreatic polypeptide (PP) in response to hypoxia and to 2-deoxyglucose have been investigated in conscious calves 3-5 weeks after birth. 2. A single injection of 2-deoxyglucose (200 mg/kg I.V.) produced an abrupt rise in the concentrations of pancreatic glucagon, insulin and PP in the arterial plasma. The changes in plasma insulin and PP concentration were unaffected by prior section of the splanchnic nerves but were effectively abolished by atropine (0-2 mg/kg I.V.). The rise in plasma pancreatic glucagon concentration was prevented in calves with cut splanchnic nerves that were given atropine but neither procedure alone suppressed the response. 3. 2-deoxyglucose also caused a substantial increase in the output of glucocorticoids from the right adrenal gland together with a pronounced rise in adrenal blood flow. There was also a small but significant increase in catecholamine output from the adrenal medullae in these animals. 4. Intense hypoxia caused a pronounced increase in the concentration of PP in the arterial plasma. This was found to resemble the glucagon response to intense hypoxia in that it persisted in animals with cut splanchnic nerves that were given atropine. Less intense hypoxia caused a rise in plasma pancreatic glucagon concentration (but not PP) that was abolished by section of the splanchnic nerves. The changes in plasma insulin concentration in these experiments were consistent with the conclusion that they were secondary to changes in plasma glucose concentration. 5. It is concluded that pancreatic endocrine responses to both moderate hypoxia and 2-deoxyglucose are mediated by the autonomic innervation.
 ...
PMID:The role of the autonomic nervous system in the control of glucagon, insulin and pancreatic polypeptide release from the pancreas. 69 Sep 43

Conventional insulins contain impurities which are immunogenic; these include pancreatic polypeptide (PP), glucagon and somatostatin and intermediates of insulin synthesis co-extracted during purification. Monocomponent (MC) insulins are free of these contaminants. In 49 insulin-treated diabetic patients, antibodies were found to insulin (94%), pro-insulin (68%) and PP (68%). Antibodies to glucagon and somatostatin were not detected. There was a significantly lower mean maximum binding and titre of insulin and PP antibodies and total circulating insulin (i.e. antibody bound and free) in patients receiving MC insulin. In patients treated with MC insulins for longer than 2 years there was a significant fall in the mean maximum binding of insulin and total serum insulin, but no consistent change in diabetes control and daily insulin dose. It seems that except in the special instances of fat atrophy, insulin allergy and certain cases of insulin resistance, there is no need to resort to MC insulin.
 ...
PMID:Circulating antibodies in diabetics treated with conventional and purified insulins. 69 12

The regional concentrations of pancreatic polypeptide (PP), insulin, and glucagon and the cellular distribution of PP were studied in 13 human and nine canine pancreases by radioimmunoassay, immunoperoxidase localization, and cell quantitation. PP concentration was highest in both the uncinate process and the head of the human pancreas and in the right lobe of the canine pancreas. In contrast, glucagon and insulin levels were higher in the body and tail of both the human and canine pancreases. Human F-cells, which contain PP, were located primarily at the periphery of the islets, although a few F-cells were scattered throughout the ducts and acini. Canine F-cells were located in ducts, acini, and islets; the relative proportion of canine F-cells in the endocrine and exocrine tissues differed according to location. Cellular quantitation of F-cells in both species correlated significantly with the tissue concentration of PP in all regions studied, validating the use of morphometric techniques to quantitate the regional distribution of PP.
 ...
PMID:Regional distribution and concentration of pancreatic polypeptide in the human and canine pancreas. 75 45

The isolated perfused canine pancreas with duodenal exclusion was used to examine islet hormone output in response to arginine and exogenous glucagon and insulin. Exogenous glucagon (100 ng/ml) stimulated insulin and somatostatin secretion, which occurred in a biphasic pattern. The insulin response to glucagon was markedly enhanced by increased perfusate glucose, unlike the somatostatin response, which was little affected. The insulin and somatostatin responses were seen between 15 and 45 s after the glucagon stimulus. Pancreatic polypeptide secretion was uninfluenced by exogenous glucagon. Biphasic release of glucagon, somatostatin, and pancreatic polypeptide was evoked by 10 mM arginine, the responses first being apparent within less than 30 s. Exogenous insulin (50 mU/ml) infused for 10 min had no statistically significant effect on glucagon, somatostatin, or pancreatic polypeptide secretion. This study suggests that these four islet hormones may all be involved in the dynamic mechanisms of nutrient metabolism. In addition, potential intra-islet paracrine effects are identified.
 ...
PMID:Somatostatin and pancreatic polypeptide secretion: effects of glucagon, insulin, and arginine. 75 49

Long term reversal of alloxan diabetes has been accomplished by intraperitoneal isotransplantation of enzymatically dispersed neonatal pancreas. In contrast, allotransplanted recipients showed only a transient recovery from the alloxan diabetes followed by a return to the diabetic state at the time of the homograft rejection. These data strongly suggest that the reversal of the diabetic state was a consequence of the transplanted islets. This conclusion is further supported by quantitative analysis of biopsied pancreases from successfully reversed recipients which reveals only 3% of the normal beta cell mass. By comparison, recovery of transplanted islets composed primarily of aldehyde fuchsin positive beta cells was routinely accomplished in these recipients. Utilization of the more specific unlabeled immunoperoxidase method has revealed that some of the transplanted islets are composed of cells positive for glucagon and somatostatin, as well as insulin. Other recovered transplanted islets (generally smaller in size) are composed primarily of one cell type or the other. The presence of insulin, glucagon, somatostatin, and delete pancreatic polypeptide positive cells in the islets of normal rat pancreas has been confirmed. In addition, cells reacting positively for these hormones have been observed in the alloxan diabetic rat pancreatic islets and in islets from reversed recipients. The time required for the disappearance of glycosuria and hyperglycemia (usually occurring from one to eleven weeks posttransplantation) appeared to be related to the amount and age of the donor islet tissue transplanted. Fetal islet tissue was more effective on a per milligram basis in reversing the diabetic state. In addition, while reversal was obtained by transplantation of as little as 5 mg of neonatal islet tissue, relatively large amounts (20 mg) were required before successfully reversed recipients responded normally to glucose tolerance test. By comparison, a similar reversal of diabetes with normal response to glucose load was attained by transplanting only 3 mg of fetal islet tissue. Quantitative morphological evidence of large increases in absolute islet mass, obtained in fetal transplants at the renal subcapsular site suggests that the superiority of fetal islet donor tissue may by in its high growth potential. No adverse effects of an in vitro organ culture period, prior to transplantation, were observed with regard to the ability of neonatal tissue to reverse the diabetic state or for fetal islet tissue to continue to survive at the renal subcapsular site. Likewise, no advantage in regard to amelioration of the homograft rejection response was observed in cultured islet tissue; allotransplants of which were rejected at the kidney site.
 ...
PMID:Transplantation of islet tissue in the rat. 82 63

The immunocytochemical technique for the cellular localization of hormones allows a precise identification of islet cell types responsible for the production of insulin, glucagon, somatostatin and pancreatic polypeptide. A systematic study of Rat pancreas has revealed a hitherto undescribed morphological heterogeneity of islets. In fact, the cellular composition of islets differs according to their anatomical distribution. The "PP islets" are preferentially located in the inferior 2/3 of the head of the pancreas, whilst "glucagon islets" populate the remainder of the gland.
 ...
PMID:[Pancreatic polypeptide islets and glucagon islets : distinct topographic distribution in rat pancreas]. 82 58

In addition to established gastrointestinal hormones--secretin, cholecystokinin-pancreozymin (CCK-PZ), gastrin, and glucagon---some 30 polypeptides with gastrointestinal actions can be listed. New aspects of these substances include the following: Gastrin and vasoactive intestinal peptide (VIP) can be also encountered in the central nervous system and may act as transmitters. CCK-PZ-serum concentrations are found markedly elevated in patients with exocrine pancreatic insufficiency; this may provide the opportunity to establish a realtively simple screening test. Moreover, there is evidence that serum-CCK-PZ levels serve as satiety signal. Secretin secretion is said to be enhanced in hunger and then to act as a lipolytic hormone. In addition to enteroglucagon, a gastrintestinal peptide identical to pancreatic glucagon has been detected. Gastric inhibitory polypeptide (GIP) inhibits gastric secretion and motility (enterogastrone activity) and together with glucose it stimulates insulin release (incretin activity). Motilin increases lower esophageal sphincter pressure, enhances gastric pepsin secretion and slows down gastric evacuation. Serum levels of pancreatic polypeptide may be found elevated as a diagnostic index in patients with endocrine peptide tumors of the pancreas. Recently, the potential importance of local (paracrine) actions of gastrointestinal polypeptides has been amphasized. Predominantly paracrine activity is exhibited by some prototype hormones, e.g. somatostatin, substance P, bombesian, and the non-polypeptide compounds, prostaglandins.
 ...
PMID:[New views on gastrointestinal hormones]. 85 99

A pancreatic polypeptide with some hormonal properties has been purified from chicken and turkey pancreas using acid-ethanol extraction, gel filtration and anion-exchange chromatography. The material has been crystallised. The crystals are monoclinic with space group C2. Preliminary isomorphous replacement experiments have so far provided a single-site derivative with Hg(NO3)2. A low-resolution electron density map phased with this derivative using anomalous scattering considered together with Patterson function calculations suggest that the molecules are partly helical and are arranged as a compact dimer about the crystallographic two-fold axis. The structure and association of these molecules are compared with those of insulin and glucagon, pancreatic protein and polypeptide hormones respectively, which have been studied in great detail.
 ...
PMID:Purification, crystallisation and preliminary X-ray studies on avian pancreatic polypeptide. 91 91


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>