Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0432222 (SEM)
 47,337 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Pancreatic polypeptide was infused intravenously in healthy fasting subjects at 1 pmol kg-1 (n = 7) and 4 pmol kg-1 min-1 (n = 10) producing plasma PP concentrations of 223 +/- 37 pmol/l (mean +/- SEM) and 891 +/- 64 pmol/l respectively. These levels are similar to and four-fold higher than those seen after a normal mixed breakfast in healthy young adults. In a separate study five healthy subjects ingested a small breakfast during infusion of PP on different days at 1 pmol kg-1 min-1 and 2 pmol kg-1 min-1 respectively. PP at 1 pmol kg-1 min-1 caused a marked reduction in fasting plasma motilin concentrations to 20% of the basal level (p less than 0.001). There were, however, no significant changes in plasma concentrations of insulin, glucagon, gastrin, secretin, enteroglucagon, gastric inhibitory peptide or neurotensin. Despite previous reports possibly implicating PP in metabolism, there were no significant effects on blood levels of glucose, alanine lactate, 3-hydroxybutyrate, glycerol or non-esterified fatty acids, either in the fasting state or after the ingestion of food. Although it seems unlikely that PP is a major hormonal regulator of intermediary metabolism in man, its ability to suppress motilin at physiological concentrations suggests the possibility of an indirect influence on digestive motor function.
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PMID:Effects of pancreatic polypeptide on motilin and circulating metabolites in man. 678 20

Fasting plasma secretin determined in nine healthy subjects, twelve patients with active duodenal ulcer and four with Zollinger-Ellison syndrome were 3.2 +/- 0.4, 5.1 +/- 1.2 and 20.3 +/- 1.3 pmol/l respectively (mean +/- SEM). Cimetidine significantly (P less than 0.05) reduced levels in those with duodenal ulcer, as did gastric aspiration in the Zollinger-Ellison group. A significant correlation (P less than 0.001) was found between basal acid output and mean fasting plasma secretin. After a solid meal and subsequent liquid soft drink, no sustained mean rise in plasma secretin was observed; changes in secretin appeared to coincide in time with rapid falls in duodenal pH, though little relationship could be established between the absolute level of pH and changes in plasma secretin. The mean peak post-prandial rise in plasma secretin observed after solids was significantly (P less than 0.05) greater in duodenal ulcer patients than controls (9.1 +/- 1.1 versus 6.7 +/- 0.5 pmol/l) as was the mean integrated post-prandial release (1002 +/- 110 versus 710 +/- 67 pmol min-1 1(-1)). Cimetidine reduced both rises (P less than 0.05) and was associated with significantly less duodenal pH readings below 4 (P less than 0.001). These results suggest that gastric acid is a major release mechanism for plasma secretin both fasting and after meals but it is likely the acid load rather than absolute pH in the duodenum which determines circulating levels.
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PMID:Gastric acid regulates the release of plasma secretin in man. 681 27

Serum immunoreactive trypsin (IRT) under basal conditions and after pancreatic stimulation with secretin was studied in 10 patients with type IV hyperlipoproteinemia (HLP) and in 10 control subjects. No significant difference was observed between basal values of the two groups (p = NS). The increase of serum IRT was already significant 5 minutes after secretin administration (p < 0.01) and persisted with significance for one hour in both groups. The integrated trypsin output (ITO) was significantly greater in type IV HLP than in controls (510.3 +/- 17.8 and 72.2 +/ 17.6 respectively, mean +/- SEM, p < 0.0125). Only 2 (20%) of 10 patients with HLP had an ITO in the range of the controls. No significant correlation was found between ITO and triglyceride levels (p = NS). The response of serum IRT to secretin in HLP patients appears comparable to that observed in alcoholics and in patients with chronic pancreatitis with mild to moderate exocrine dysfunction, in whom there may be an abnormal regurgitation of trypsin-like material into the blood stream after secretin stimulation, probably due to an obstruction to pancreatic secretory flow. A similar obstructive mechanism may be hypothesized also in patients with HLP, but no data concerning the exocrine pancreatic secretion and the histological features of the pancreas are available to confirm this hypothesis.
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PMID:Serum immunoreactive trypsin in type IV hyperlipoproteinemia. 693 55

Serum trypsin concentrations within the portal venous system have been measured in man during transhepatic portal venography in an attempt to determine its source. In eight experiments, mean serum trypsin concentration at the splenic hilum was 180 +/- 25 ng/ml (mean +/- SEM). Trypsin concentration in the rest of the splenic vein was not significantly different. The mean concentrations in the portal vein (210 +/- 32 ng/ml) and within the superior mesenteric vein (233 +/-- 29 ng/ml) were, however, significantly higher than at the hilum (P less than 0.05). Following cholecystokinin-pancreozymin (CCK-PZ) and secretin stimulation, marked increases in serum trypsin concentration were seen within the portal vein (two patients) and deep within the superior mesenteric (two out of three patients). We conclude that circulating serum trypsin is derived, at least in part, from intestinal reabsorption.
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PMID:Origin of circulating serum immunoreactive trypsin in man. 697 4

The mean fasting serum secretin level determined in newborn swine was found to be 298.0 +/- (SEM) 5 pg/ml, significantly higher than that in the adult animal. Intraduodenal infusion of 0.1 N HCl produced dramatic elevation of the mean serum secretin level to 2,090 +/- 340 pg/ml. The tissue secretin concentration of duodenal mucosa as well as the molecular species of tissue secretin were found to be identical to that of the adult swine. The mean disappearance half-life of exogenously administered secretin in the newborn swine was significantly prolonged over adult values, to 3.6 min. These data suggest that delayed secretin degradation can be implicated as a factor in the etiology of the hypersecretinemia in the newborn swine.
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PMID:Secretin levels in plasma and tissue of the neonatal swine. 712 6

Dose-response curves of acetylcholine (ACh), gastrin, and glucagon given alone or in combination with a submaximal dose of secretin (S;' 5.0 U/h) plus cholecystokinin (CCK; 1.0 U/h) were studied in the isolated perfused rat pancreas. ACh (25 x 10-9 mol/h) increased the basal secretory flow ( mean +/- SEM: 1.19 +/- 0.22 microliter/min) by 693% and protein output (2.7 +/- 0.2 microgram/min) by 1726%. The protein secretion evoked by S plus CCK was further increased by ACh to a maximum of 26% whereas the volume secretion remained unaltered. Gastrin (100 ng/h) stimulated the protein output by 352% and, when combined with S and CCK, up to further 23% and the secretory flow by 37%. Glucagon evoked a significant (P less than 0.005) increase of the protein output, but decreased the volume as well as the protein output (by 43% and 32%, respectively; P less than 0.05) when it was combined with the tested doses of S and CCK.
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PMID:Effect of acetylcholine, gastrin, and glucagon alone and in combination with secretin and cholecystokinin on the secretion of the isolated perfused rat pancreas. 732 54

Gastric acid secretion and gastrointestinal hormone levels were measured in healthy non-diabetic subjects after metformin treatment (1.5 g/day). The maximum acid output was increased from 15.7 +/- 3.9 mmol/h (mean +/- SEM) to 30.0 +/- 7.1 mmol/h (p < 0.05) and the peak acid output was increased from 16.4 +/- 4.1 mmol/h to 31.7 +/- 7.2 mmol/h (p < 0.05) after two weeks treatment. Serum insulin, gastric inhibitory polypeptide and secretin levels were normal. After treatment for one week, however, there was a significant increase in fasting vasoactive intestinal peptide (VIP) from 83 +/- 6 ng/1 to 102 +/- 9 ng/1 (p < 0.02) and in stimulated VIP from 58 +/- 5 ng/1 to 79 +/- 5 ng/1 (p < 0.05). Stimulated glucagon-like immunoreactivity (GLI) was also increased from 82 +/- 10 ng/1 to 174 +/- 24 ng/1 (p < 0.01) after one week's treatment. It is suggested that metformin acts as a weak histamine agonist.
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PMID:The effect of metformin treatment on gastric acid secretion and gastrointestinal hormone levels in normal subjects. 741 69

Pancreatic polypeptide (PP) can be used as a marker for endocrine active tumors originating from the pancreas. After intravenous administration of secretin, individually divergent increases in plasma PP concentration can be observed hampering interpretation of the stimulation test. Under certain circumstances elevated basal PP concentrations can be observed. Besides age, renal insufficiency and diabetes, hypoglycemia can cause high PP levels. We therefore inquired whether in patients with atypically high increase of PP after secretin this increase could be caused by hypoglycemia during the secretin stimulation test. In order to test this hypothesis we prospectively determined the plasma glucose and insulin concentrations in addition to the routinely measured gastro-intestinal hormones in 19 patients referred for secretin provocation test. In the 16 patients in whom the increase of PP was not due to an endocrine active tumor or renal insufficiency, PP rose to 170 +/- 57 pmol/l (+/- SEM) 2 minutes after secretin administration. In parallel, plasma insulin concentration increased to 365 +/- 51 pmol/l 2 minutes after secretin. The maximal insulin concentrations correlated significantly with the PP concentrations observed at the same time (R = 0.73, p < 0.01). The mean glucose concentration, however, remained constantly between 4.8 +/- 0.3 and 5.2 +/- 0.3 mmol/l and there was no correlation between the peak plasma PP concentrations after secretin and the plasma glucose concentrations (R = 0.07). The minimal glucose concentrations observed were 3.3 mmol/l in three patients (30 minutes after secretin in 2 patients and 45 minutes after secretin in one). The mean plasma glucagon concentration rose to 22.5 +/- 4.1 pmol/l 10 minutes after secretin.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:[Abnormal increase in pancreatic polypeptide in the secretin-provocation test: hypoglycemia-induced?]. 774 Feb 87

In the present study, we examined the effect of pretreatment with VIP and various peptides structurally related to VIP such us PHI, helodermin, and secretin on VIP receptor number and affinity, as well as VIP-stimulated cyclic AMP production in rat peritoneal macrophages. Short-term (5-30 min) exposures of rat peritoneal macrophages to 0.1 microM VIP induced a rapid reduction in specific binding. Pretreatment for 15 and 30 min caused 26% (SEM = 6) and 48% (SEM = 4) reduction in specific binding, respectively. The maximal effect was observed at 120 min, causing a decrease of 67% (SEM = 6) in specific binding. Pretreatment with 0.1 microM VIP for 15, 30, and 120 min caused 23% (SEM = 9), 52% (SEM = 4), and 76% (SEM = 4) reduction in cyclic AMP production, respectively. Only VIP concentrations at the nanomolar level and higher were shown to be effective. The potency of VIP and related peptides to desensitize was similar to their potency to occupy receptors and to activate cyclic AMP production. The internalization of radioiodinated VIP was also studied. It was shown that receptor-bound ligand is internalized during the downregulation process. However, the diminution in VIP binding to macrophages was not completely explained by internalization.
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PMID:Homologous regulation of vasoactive intestinal peptide (VIP) receptors on rat peritoneal macrophages. 778 61

Pituitary adenylate cyclase-activating polypeptide-38 (PACAP38) is a neuropeptide related to vasoactive intestinal peptide-secretin-glucagon which stimulates adenylate cyclase in cultured rat pituitary cells and stimulates LH and FSH release in vitro and in vivo. Because the cAMP-protein kinase-A pathway regulates the gonadotropin subunit messenger RNAs (mRNAs) and modulates GnRH-stimulated gonadotropin secretion in vitro, we examined the effects of PACAP38 on gonadotropin secretion and subunit mRNA levels. Anterior pituitary cells were prepared from 7-week-old male rats castrated at 5 weeks of age. In monolayer cultures stimulated with GnRH, 0.1-10 nM PACAP38 decreased (P < 0.05) the EC50 for GnRH dose-dependently without affecting the maximum LH secretory response. Cells were next stimulated with 1-min pulses of 2.5 nM GnRH every hour for 9 h in the absence or presence of 10 nM PACAP38, which was perifused continuously. The amplitude of GnRH-induced LH, FSH, and alpha-subunit secretory episodes from PACAP38-treated cells rose (P < 0.01) gradually to 233 +/- 54%, 197 +/- 44%, and 378 +/- 104%, respectively (mean +/- SEM; n = 5 experiments), of the value for control cells lacking PACAP38. This enhancement was sustained for at least 3 h after PACAP38 was removed from the perifusion medium. With PACAP treatment, interpulse secretion of LH and alpha-subunit increased gradually (P < 0.01) to 174 +/- 21% and 212 +/- 64% of the value for chambers stimulated with GnRH alone (control), respectively, whereas interpulse secretion of FSH declined (P < 0.001) to 75 +/- 7% of the control value. In contrast to the gradual effect of PACAP38 to enhance GnRH-induced hormone secretion, PACAP38 alone produced a transient burst of gonadotropin secretion. At the completion of the perifusions, total RNA was extracted and gonadotropin subunit mRNA levels were determined by Northern analysis. GnRH increased (P < 0.01) FSH beta mRNA to 438 +/- 52% of the level in cells stimulated with medium alone (control). Adding PACAP38 to the perifusion medium partially blocked (P < 0.01) the effect of GnRH (178 +/- 20% of the control value), and PACAP38 alone reduced (P < 0.01) FSH beta mRNA levels to 31 +/- 3% of the control value. By contrast, alpha-subunit mRNA levels were increased by both PACAP38 (143 +/- 4% of the control value; P < 0.01) and GnRH (121 +/- 2% of the control value; P < 0.05).(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:Effects of pituitary adenylate cyclase-activating polypeptide on gonadotropin secretion and subunit messenger ribonucleic acids in perifused rat pituitary cells. 791 30


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