Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00790 (PGA)
 2,475 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Prostaglandins A1, B1, E2, Falpha and PRA have been measured by radioimmunoassay in peripheral or renal venous blood of different groups of hypertensive and control subjects. PGA1 and PGE2 were significantly increased in renal, renovascular, labile and essential hypertension. PGFalpha was significantly increased only in patients with unilateral renal atrophy and in some patients with renovascular and essential hypertension. There was a significant positive correlation between PRA and PGA1 or B1, but not with PGE2 or Falpha. The increase of PGA and PGE represents a secondary antihypertensive, diuretic and natriuretic mechanism, the increase of PGF a direct hypertensive mechanism.
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PMID:Prostaglandins and high blood pressure. 35 39

The effect of representative agents of three classes of antisecretory compounds; prostaglandins, histamine H2-receptor antagonist, and anticholinergic agents, on acute gastric mucosal lesions produced by topical aspirin (200 mg/kg) plus HCl (150 mM) in the pylorus-ligated rat was studied. Acid was given exogenously so as to negate any antisecretory effect of the drugs studied. Both nonantisecretory and antisecretory doses of each agent as determined by preliminary secretory studies were employed. The postaglandin analogue 16,16-dimethyl prostaglandin E2, the H2-receptor antagonist cimetidine, and the anticholinergic agent probanthine, in both doses studied, all significantly reduced lesion formation. The H1-receptor antagonist mepyramine neither protected by itself nor enhanced the protective effect of cimetidine. Pepsin release into the gastric content increased with increasing mucosal damage. However, addition of pepsin to the gastric instillate had no effect on severity lesions in any group, which indicates that the increased pepsin was the result of, and not the cause of, the mucosal damage. The findings indicate that all three classes of antisecretory agents studied are also cytoprotective, i.e., they can protect against gastric mucosal injury by topical aspirin plus HCl by some mechanism other than inhibition of acid and pepsin secretion.
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PMID:Topical aspirin plus HCl gastric lesions in the rat. Cytoprotective effect of prostaglandin, cimetidine, and probanthine. 36 95

1. The renin present in human amniotic fluid was found to have an apparent Mr of 58 000 by gel filtration and is thus bigger than renin in untreated kidney extracts and plasma (Mr approximately 40 000). 2. Treatment with pepsin (40 microgram/ml pH 4.8, 2 h, 22 degrees C) caused a 6-fold increase in activity of this renin species, although Mr was not very different (57 000). 3. Unlike renal renin, renin in human amniotic fluid was not a glycoprotein and behaved similarly on concanavalin A-Sepharose before and after activation by pepsin. 4. Ion-exchange chromatography demonstrated a small change in the ionization properties of human amniotic fluid renin after activation by pepsin. 5. Pepsin-mediated activation resulted in a five-fold increase in V, but only a small decrease in the Km of renin to 39% of normal, so that the increase in activity observed was not due to an increase in the affinity of the enzyme for its substrate. The kinetic data were consistent with the theory of noncompetitive inhibition. 6. The activation of human amniotic fluid renin by pepsin may be caused by a change in the tertiary structure of the molecule subsequent to a proteolytic action that does not remove detectable polypeptide components.
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PMID:Properties of the activation by pepsin of inactive renin in human amniotic fluid. 36 68

Dog IgG was produced by fractionation procedures used for the production of clinically used i.v. gammaglobulins. Chemical modification of dog IgG was done by pepsin or beta-propiolactone treatment. The intravascular half-life of beta-propiolactone IgG was 8.5 +/- 2.1 days compared to 4.5 +/- 1.6 days of pepsin treated IgG. Tissue concentrations of radioactive labelled beta-propiolactone IgG were generally higher than of pepsin digested IgG. Pepsin treated Igg was degraded to a significantly higher extent (26% of the administered radioactivity was bound to fragments smaller than 6000 MW after three days) than beta-propiolactone IgG (9% fragments after the same interval, P less than 0.001). It is concluded that the short intravascular half-life of pepsin IgG cannot be explained by increased extravascular filling, but is due to rapid degradation and excretion via the kidneys. There was no obvious difference in elimination and organ distribution between standard and beta-propiolactone IgG.
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PMID:Elimination and organ distribution of intravenously administered allogeneic and xenogeneic IgG modifications. (Standard IgG, F (ab)2-fragments and beta-propiolactone treated IgG) in dogs. 36 71

The reactivity of F(ab)2 fragments of sperm antibodies was studied in agglutination, immobilization and immunofluorescence tests. Pepsin digestion of full serum was an easy and effective procedure for preparing F(ab)2 fragments. Compared to the reactions with serum, F(ab)2 preparations revealed only a moderate decrease in agglutination titres but a complete loss of immobilizing activity. In immunofluorescence tests, nonspecific background staining was strongly reduced by using F(ab)2 fragments, thereby offering a more reliable basis for the reading of reactions. Even though the titres obtained with serum and F(ab)2 preparations did not differ essentially, it is suggested that the use of F(ab)2 fragments in IF-tests on spermatozoa may help to provide a higher degree of reproducibility.
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PMID:Reactivity of F(ab)2 fragments of sperm antibodies in agglutination, immobilization and immunofluorescence tests. 36 67

The susceptibility of a monodeamidated RNAaseA (RNAaseAa1) towards carboxypeptidaseA , alpha-chymotrypsin and pepsin has been studied. Similar to RNAaseA, the C-terminal of RNAaseAa1 is not available for carboxypeptidaseA hydrolysis. The thermal stability of RNAaseAa1 as probed through chymotryptic digestion is found to be less than that of RNAaseA. Preliminary chromatographic analysis of the digested material, however, suggests that the nature of thermal transition might be the same in the two proteins. Pepsin inactivates RNAaseAa1 more slowly than does RNAaseA. Accordingly, less peptide bonds, almost half that of RNAaseA, are cleaved by pepsin in RNAaseAa1. The accumulation of RNAase-P type intermediates is not evident during peptic digestion of RNAaseAa1. Reaction with O-benzoquinone at low pH shows that methionines of the deamidated protein seem to have higher reactivities. These observations indicate a different structure for RNAaseAa1 at elevated temperature and low pH.
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PMID:Proteolytic susceptibility and methionine modification of monodeamidated ribonuclease A. 37 43

Gastric function and histology were investigated in 24 patients with untreated chronic renal failure. At endoscopy nine patients had oesophagitis, 12 patients were considered to have gastritis, and the duodenum appeared inflamed in 20 patients. Endoscopic biopsies were taken at standard sites in the stomach and duodenum; gastritis was found in all patients, and 17 patients had duodenitis. Stimulated acid secretion was impaired in seven out of 20 patients and acid hypersecretion was found in a further two patients. Pepsin output correlated well with acid output in these patients. Fasting serum gastrin levels were elevated in 12 of the 19 patients tested. Patients with atrophic gastritis had low acid outputs and hypergastrinaemia, and when extensive gastritis was present, the patients tended to have more severe renal failure and hyposecretion of acid. Three patients were studied again after regular haemodialysis or renal transplantation and were found to show marked endoscopic and histological improvement.
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PMID:Gastric function and histology in chronic renal failure. 37 52

Cimetidine-induced inhibition of gastric acid and pepsin secretion in response to histamine and pentagastrin simulation was studied in four healthy young subjects. Different doses of histamine and pentagastrin were administered alone and in combination with cimetidine on separate days; the order of administration was randomized. As the dose of histamine increased, the inhibitory effect of 0.6mg.kg-1h-1 of cimetidine on acid output decreased. With supramaximal histamine stimulation the inhibition was completely overcome. These results are consistent with competitive inhibition of histamine-stimulated acid output by cimetidine in man. After pentagastrin stimulation inhibition of acid output by cimetidine could not be overcome by increasing the dose of the stimulant, suggesting a noncompetitive inhibition of pentagastrin-evoked acid output. It is concluded that the kinetics of cimetidine-induced inhibition of histamine- and pentastrin-stimulated gastric acid output are different. At approximately half maximal stimulation of acid secretion, cimetidine was a more potent inhibitor of histamine than of pentagastrin. Pepsin output in response to both histamine and pentagastrin stimulation was also inhibited by cimetidine.
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PMID:Effect of cimetidine on histamine- and pentagastrin-stimulated gastric secretion in healthy subjects. 37 77

C3 nephritic factor (C3NeF), found in the sera of some patients with membranoproliferative glomerulonephritis, has been shown to be composed of two heavy and two light chains, like IgG; in addition it shares antigenic determinants with IgG. Purified C3NeF binds to the amplification convertase of complement, C3b,Bb, and thereby prevents decay of its C3-cleaving potential. The capability of C3NeF to bind to C3b,Bb was used as a means for purifying C3NeF to homogeneity. The investigation described in this report suggests that binding of C3NeF to C3b,Bb occurs via the Fab portion of the molecule. Pepsin treatment of eight C3NeF preparations resulted in an average loss of 76% of C3NeF functional activity. Papain treatment induced a loss of approximately 90%. The decrease in functional activity could be attributed to the accelerated rate of dissociation of 125I-F(ab')2 and 125I-Fab fragments from stabilized cell-bound C3b,Bb. The dissociation rate of 125I-F(ab')2 from C3b,Bb was comparable with the decay of the functional activity of C3b,Bb stabilized by F(ab')2 or Fab fragments of C3NeF. Although these results suggest that the stabilizing activity of C3NeF is mediated by the Fab portion of the molecule, it was found that the Fc portion also contributes to its functional activity.
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PMID:Further evidence for the antibody nature of C3 nephritic factor (C3NeF). 37 17

Endothelial cells isolated from bovine aorta synthesize and secrete type III procollagen in culture. The procollagen, which represents the major collagenous protein in culture medium, was specifically precipitated by antibodies to bovine type III procollagen and was purified by diethyl-aminoethylcellulose chromatography. Unequivocal identification of the pepsin-treated collagen was made by direct comparison with type III collagen isolated by pepsin digestion of bovine skin, utilizing peptide cleavage patterns generated by vertebrate collagenase, CNBr, and mast cell protease. The type III collagen was hydroxylated to a high degree, having a hydroxyproline/proline ratio of 1.5:1.0. Pulse-chase studies indicated that the procollagen was not processed to procollagen intermediates or to collagen. Pepsin treatment of cell layers, followed by salt fractionation at acidic and neutral pH, produced several components which were sensitive to bacterial collagenase and which comigrated on sodium dodecyl sulfate-polyacrylamide gel electrophoresis with alpha A, alpha B, and type IV collagen chains purified from human placenta by similar techniques. Bovine aortic endothelial cells also secreted fibronectin and a bacterial collagenase-insensitive glycoprotein which, after reduction, had a molecular weight of 135,000 on sodium dodecyl sulfate-polyacrylamide gel electrophoresis (using procollagen molecular weight standards) and which was not precipitable by antibodies to cold-insoluble globulin or to alpha 2-macroglobulin. Collagen biosynthesis by these cells provides an interesting model system for studying the polarity of protein secretion and the attachment of cells to an extracellular matrix. The presence of type III collagen in the subendothelium and the specific interaction of this protein with fibronectin and platelets suggest the involvement of this collagen in thrombus formation following endothelial cell injury.
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PMID:Collagen synthesis by bovine aortic endothelial cells in culture. 39 Dec 67


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