Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P15088 (mast cell)
 14,925 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Cold-restraint stress produced stomach ulceration which was accompanied by a decreased glandular mucosal mast cell count and blood flow. Pretreatment with FPL55712, a leukotriene antagonist, dose-dependently prevented ulcer formation and mast cell depletion; however, it did not affect the reduced mucosal blood flow, nor did it significantly influence acid secretion and pepsin output. The role of the leukotrienes in stress ulceration is discussed in the light of the findings with FPL55712 on gastric glandular mucosal mast cell degranulation.
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PMID:The protective mechanism of FPL55712 against stress-induced gastric ulceration in rats. 273 25

The use of fluoro ketones as inhibitors of hydrolytic enzymes has been investigated. The acetylcholine analogues 6,6-dimethyl-1,1,1-trifluoro-2-heptanone and 3,3-difluoro-6,6-dimethyl-2-heptanone are inhibitors of acetylcholinesterase with Ki values of 16 X 10(-9) M and 1.6 X 10(-9) M, respectively. These fluoro ketones are 10(4)-10(5) times better as inhibitors than the corresponding methyl ketone. Since nucleophiles readily add to fluoro ketones, it is likely that these compounds inhibit acetylcholinesterase by formation of a stable hemiketal with the active-site serine residue. Fluoro ketone substrate analogues are also inhibitors of zinc metallo- and aspartylproteases. 2-Benzyl-4-oxo-5,5,5-trifluoropentanoic acid is an inhibitor of carboxypeptidase A (Ki = 2 X 10(-7) M). Trifluoromethyl ketone dipeptide analogues are good inhibitors of angiotensin converting enzyme. An analogue of pepstatin that contains a difluorostatone residue in place of statine has been prepared and found to be an extremely potent inhibitor of pepsin (Ki = 6 X 10(-11) M). The hydrated ketones are probably the inhibitory species since they are structural mimics of the tetrahedral intermediate that forms during the hydrolysis of peptide substrates.
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PMID:Fluoro ketone inhibitors of hydrolytic enzymes. 299 May 41

The chromone FPL 52694 is a preparation thought to act by stabilizing mast cell membranes, thus reducing free histamine in the gastric mucosa. The effect of FPL 52694 on overnight gastric secretion was tested in 15 dyspeptic individuals in a double-blind crossover study. Each individual received the chromone preparation or placebo for 1 week. After each of the treatment periods gastric secretion was collected after 6 h of fasting by continuous suction for 8 h during the night. A significant reduction of the total acid secretion was observed after active drug compared with placebo administration, mean reduction being 17% (median, 23%). No difference was observed between 30-min and 60-min periods. FPL 52694 had no significant effect on pepsin, intrinsic factor (IF) or volume secretion. The difference in the effect on pepsin and acid secretion, reflected in a significant increase in the pepsin to acid ratio, indicates that intrinsic histamine, similarly to extrinsic histamine, has a specific effect on parietal cells. The difference in effect on acid and IF secretion indicates that intrinsic histamine not only has a specific effect on parietal cells but also has different effects on the secretory substances contained in this cell. Since IF was not reduced by the use of FPL 52694, it may be that this substance will not influence vitamin B12 metabolism.
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PMID:A double-blind crossover study of the effect of a chromone carboxylic acid, FPL 52694, on overnight fasting gastric acid secretion. 309 13

In the study of the covalent immobilization of aminoacylase, thermitase, pepsin, trypsin, chymotrypsin, elastase, subtilisin, penicillinamidohydrolase, carboxypeptidase A, cystathionine-beta-synthase, and anticathepsin D-IgG to copolymers of 2-hydroxyethyl methacrylate and ethylene dimethacrylate (Separon HEMA) containing epoxy groups a marked influence of added salts on the immobilization efficiency was observed. Yields in covalently bound active enzymes were dependent on the concentrations and type of ions added, which can be arranged according to the Hofmeister series. At a distinct concentration, the salting-out ions cause a protein-matrix hydrophobic interaction which is a prerequisite for the covalent bond formation.
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PMID:Influence of salts on the covalent immobilization of proteins to modified copolymers of 2-hydroxyethyl methacrylate with ethylene dimethacrylate. 340 61

The effects of zinc deficiency on gastric secretion and on cold-restraint stress-induced ulceration in rat stomachs have been studied. Administration of graded zinc deficient diets for 5 weeks significantly depressed the serum zinc concentration and decreased body weight gain in the rats. These diets significantly increased the gastric secretory volume, acid and pepsin. Zinc deficiency produced or aggravated the formation of glandular ulceration in the absence or presence of stress, respectively; it also decreased the mast cell count in the gastric glandular mucosa. It is concluded that zinc deficiency adversely affects the rats by reducing the body weight gain and producing ulceration which is probably mast cell-mediated. On the other hand, it increases gastric secretory functions.
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PMID:Zinc deficiency: its role in gastric secretion and stress-induced gastric ulceration in rats. 357 53

1. Evidence is given for the presence of at least five pepsinogens in a crude extract of mixed chicken stomachs. One of these was purified and could be activated to yield a single pepsin. 2. The molecular weights of the pepsinogen and pepsin were 36000 and 34000 respectively. The pepsin associated at low pH values and low ionic strength. 3. The amino acid analyses of both proteins are given. The pepsin was devoid of phosphate but contained carbohydrate. 4. The N-terminal amino acids of pepsinogen and pepsin were serine and threonine respectively. Five amino acids were released by carboxypeptidase A and it was deduced that serine may be the C-terminal one. 5. Each protein contained one thiol group per molecule as determined by titration with p-chloromercuribenzoate. The rate of the reaction was very rapid with pepsin, but much slower with pepsinogen, although the same group appeared to react in both instances. The enzymic activity of pepsin was unaffected by the modification. 6. The isoionic point of the pepsin was close to pH4.0 and the enzyme was stable for long periods at pH values up to 7.0. 7. The enzyme hydrolysed bisphenyl sulphite almost as rapidly as did pig pepsin A.
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PMID:The purification and properties of a single chicken pepsinogen fraction and the pepsin derived from it. 457 60

The distribution and metabolism of [(14)C]aflatoxin B(1) in chicken tissues were further investigated. Previously dried and frozen ethyl acetate extracts of liver, heart, gizzard, breast, leg, blood, and fecal samples were obtained from either layer or broiler chickens fed subclinical levels of [(14)C]aflatoxin B(1). Treatment of these extracts with either carboxypeptidase A, leucine aminopeptidase, pepsin, or trypsin revealed that an average of 50% of the (14)C detected in the acetate extracts was a liberated peptide (or amino acid) conjugate of [(14)C]aflatoxin B(2a). When a prepared standard of B(2a) was made by incubation of B(1) with cold dilute aqueous HCl, the R(f) values and absorbance maxima were identical with those of the tissue extracts after enzymatic treatment.
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PMID:Further characterization of tissue distribution and metabolism of (14C)aflatoxin B1 in chickens. 461 34

Erabutoxin c, a minor neurotoxic component of the venom of a sea snake Laticauda semifasciata, was isolated in pure form by repeated column chromatography on CM-cellulose columns. The toxin was crystallizable and monodisperse in rechromatography, disc electrophoresis and isoelectric focusing (isoelectric point, pH9.23-9.25). The molecular weight of the toxin, as estimated by gel filtration, was 7000. The toxin showed the same lethal activity to mice (0.13mug/g body wt., intramuscular injection) and the same effect on isolated frog muscle as erabutoxins a and b, the main toxic components of the venom. The toxin inhibited the acetylcholine contracture but not the potassium chloride contracture of muscle. Erabutoxin c consisted of 62 amino acid residues, containing one fewer lysine and one more histidine than erabutoxin a and one fewer lysine and one more aspartic acid (or asparagine) than erabutoxin b. Erabutoxin c was reduced, S-carboxymethylated and hydrolysed with trypsin. The only fragment different from the corresponding fragments from erabutoxin b was hydrolysed further with pepsin. One of the peptic fragments, which was assumed to have the aspartic acid (or asparagine) residue in question at the C-terminal end, was treated with carboxypeptidase A. The C-terminal residue was found to be an asparagine. It was therefore concluded that erabutoxin c was [51-asparagine]-erabutoxin b.
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PMID:The isolation, properties and amino acid sequence of erabutoxin c, a minor neurotoxic component of the venom of a sea snake Katicauda semifasciata. 466 80

Type IV and V collagens were localized in neurofibromas from six patients with von Recklinghausen's neurofibromatosis (NF) using the peroxidase anti-peroxidase (PAP) technique. The collagens were also isolated from neurofibromas by pepsin digestion and fractionating salt precipitations and demonstrated with sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS-PAGE). Staining reactions for both collagens were detected in most of the cells in the disorganized NF tumor tissue. These cells also were S-100 protein-positive and were considered to be of Schwannian cell origin, while the type IV collagen-negative cells showed fibroblastoid, mast cell and histiocytic characteristics. Type IV collagen detection was also used to study the structure of a neurofibroma after 3 weeks in tissue culture. The proportion of fibroblastoid, type IV collagen-negative cells increased significantly in the cultured neurofibromas and "buds" containing solely fibroblastoid cells were seen at the periphery of the tumor fragments. Cultured 6th passage tumor cells produced type V but no type IV collagen as estimated with SDS-PAGE. Further, two malignant Schwannomas from a patient with NF were stained with antibodies to type IV collagen. A positive staining reaction was associated only with the vascular walls in the malignant Schwannomas suggesting that type IV collagen expression is linked with cell differentiation. The present data show that the detection of type IV collagen using the PAP-method is useful in studying the organization of tumors with mixed cell populations such as neurofibromas. Large neurofibromas might also serve as a source for the isolation of human type IV and V collagens.
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PMID:Type IV and V collagens in von Recklinghausen's neurofibromas. An immunohistochemical and electrophoretical study. 615 10

Six pigs, initially of 35 kg mean live weight, were each fitted with a re-entrant cannula. This was formed on either side of a short pouch of duodenum into which the pancreatic duct opened and which contained a simple cannula linked to the centre of the re-entrant cannula. Each pig received two diets: diet A was based on wheat starch, sucrose and casein, while diet B was based on barley and soya-bean meal. The diets were given in equal amounts at 12 h intervals. Digesta and pancreatic juice were collected continuously during three 12 h periods for each pig on each diet. Mean duodenal output: dietary intake values for diets A and B respectively were: digesta 1.80, 2.86; dry matter 1.05, 1.03; nitrogen 1.05, 1.06; trichloroacetic acid (TCA)-soluble N 7.69, 9.10; glucose 0.97, 0.89. For diet A the proportion of TCA-soluble N in total N rose from 13 to 50% during 12 h, while it was approximately 50% throughout 12 h for diet B. Mean total pepsin (EC 3.4.23.1) activities (units/24 h) were 760449 (diet A) and 1 466 571 (diet B). Salivary and gastric secretions were calculated to be approximately 4 and 8 kg/24 h for diets A and B respectively. Mean flows in pancreatic juice (g/24 h) for diets A and B respectively were: juice 1204, 2182; protein 10.94, 12.10; N 1.98, 2.14; ash 9.46, 17.31; sodium 3.88, 6.91; potassium 0.23, 0.54; calcium 0.031, 0.046; phosphorus 0.024, 0.026. Mean total enzyme activities (units x 10(-3)/24 h) for diets A and B respectively were: trypsin (EC 3.4.21.4) 138, 114; chymotrypsin (EC 3.4.21.1) 84, 84; carboxypeptidase A (EC 3.4.2.1) 5, 4; carboxypeptidase B (EC 3.4.2.2) 15, 17; amylase (EC 3.2.1.1) 1061, 981. It was calculated that the minimum amount of endogenous N from saliva and gastric secretion was 0.3-0.6 g in 24 h. This assumes no absorption of N occurred anterior to the duodenal cannula.
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PMID:Studies on gastric digestion of protein and carbohydrate, gastric secretion and exocrine pancreatic secretion in the growing pig. 640 23


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