Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0220723 (PCA)
 4,687 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A series of substituted 11-oxo-11H-pyrido[2,1-b]quinazoline-8-carboxylic acids were prepared and evaluated as antiallergy agents. Several analogues were orally active. 2-Methyl-11-oxo-11H-pyrido[2,1-b]quinoazoline-8-carboxylic acid (6) was superior to cromolyn sodium and doxantrazole orally and intravenously in the rat PCA test and a rat allergic bronchospasm model.
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PMID:Antiallergy activity of substituted 11-oxo-11 H-pyrido[2,1-b]quinazoline-8-carboxylic acids. 8 23

BL-5255, 2-(2-n-propoxyphenyl)-5-(5-1 H-tetrazolyl)pyrimidin-4 (3H)-one, effectively inhibited allergic reactions in sensitized rats or guinea pigs when administered by oral or intravenous routes as the water-soluble sodium or ethanolamine monohydrate salts. In the IgE-mediated rat PCA, BL-5255 was 50 times more potent than disodium cromoglycate by intravenous administration. When administered orally in this model, BL-5255 inhibited the PCA reaction by 50% at 0.1 mg/kg. At less than 0.1 mg/kg p.o., the compound protected conscious actively sensitized guinea pigs from aerosolized antigen-induced collapse. In N. brasiliensis-sensitized rats, BL-5255 administered at 0.1--10 mg/kg p.o. inhibited antigen-induced airway constriction in a dose-related manner. BL-5255 is not a histamine or serotonin antagonist but appears to exert its antiallergic effect by inhibiting the release of mediators.
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PMID:BL-5255, a tetrazolylpyrimidinone with potent oral antiallergy activity in animals. 9 59

A new series of 11-oxo-11H-pyrido[2,1-b]quinazolinecarboxylic acids and related analogues has been synthesized and evaluated as potential antiallergy agents. In the rat PCA test, 11-oxo-11H-pyrido[2,1--b]quinazoline-8-carboxylic acid is orally active and more potent than cromolyn sodium or doxantrazole intravenously.
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PMID:11-Oxo-11H-pyrido[2,1-b]quinazoline-8-carboxylic acid, an orally active antiallergy agent. 42 74

We tried to prepare hen's egg with low antigenicity for allergy patients. First, we examined the effects of pH, heating temperature and time on antigenicity of egg. Dried whole egg solid (DES) was dissolved in the buffer solution adjusted at various pH and heated at 120 degrees C for 10, 20 and 40 min. As a result the antigenicity didn't significantly decrease. Next, DES was treated with succinic anhydride, sodium hydroxide and was heated. The antigenicity of the resultant modified whole egg solid (MES) was much lower than that of heated whole egg solid. Antigenicity was measured precisely by enzyme immunoassay, inhibition ELISA, RAST inhibition and PCA. It was found that the antigenicity of MES was decreased less than 1/1000 of that of DES. Then SDS-polyacryl-amide gel electrophoresis and gel filtration were performed to clarify the degree of the change of egg proteins. The bands and peaks which corresponded to ovalbumin and ovomucoid known to be major allergenic proteins responsible for egg allergy disappeared and new bands and peaks were detected.
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PMID:[Development of hen's egg with low antigenicity for allergic patients]. 179 64

Mechanism of the antiallergic action of 6-methyl-N-(1H-tetrazol-5-yl)-2-pyridinecarboxamide (TA-5707F) was studied using the water-soluble sodium salt (TA-5707). 1) TA-5707 administered p.o. at the dose ca. 3 times the ID50 for the PCA reaction did not inhibit capillary dye leakage induced on the rat skin by intracutaneous injection of histamine, serotonin, bradykinin and leukotriene D4 (LTD4). 2) TA-5707, at concentrations above 10(-7) M, inhibited antigen-induced histamine release and dye leakage in the rat peritoneal cavity (passive peritoneal anaphylaxis). 3) TA-5707 inhibited both anaphylactic and compound 48/80-induced histamine release from the rat peritoneal mast cells, the IC50 being ca. 10(-5) M in both cases. It was concluded that TA-5707F exerts its antiallergic action by inhibiting the release of chemical mediators from sensitized cells.
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PMID:Studies on a new antiallergic pyridinecarboxamide TA-5707F and its sodium salt (TA-5707). II. Mechanism of antiallergic action of TA-5707. 244 38

The antiallergic activity of sodium 10-(2,3-dimethyl pentanamido)-4-oxo-4H-pyrimido [1,2-C] quinazoline-3-carboxylate-hydrate (FR50948) was studied and compared with the activities of sodium cromoglycate (SCG) and lodoxamide. FR50948 had inhibitory effects on type I and type III allergic reactions, but not on type II and IV allergic reactions. FR50948 also had weak inhibitory effects on inflammation (carrageenin paw edema and adjuvant arthritis) and SRS release from rat neutrophils, but no antagonistic effects to histamine and serotonin. The inhibitory effect of FR50948 on IgE-mediated type I allergic reactions was essentially the same as those of SCG and lodoxamide, because FR50948 inhibited the histamine release from rat peritoneal mast cells and had cross tachyphylaxis with SCG in the rat PCA test. However, FR50948, like lodoxamide, had a stronger activity than SCG and was effective by the oral route, unlike SCG which was effective only by the parenteral route. Furthermore, the inhibitory effects of FR50948 on type III reactions and inflammatory reactions were much more potent than those of SCG and equal to those of lodoxamide, and the effect on IgG-mediated PCA was stronger than that of either reference drug. These results suggest that FR50948 will be beneficial in clinical use.
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PMID:Effects of FR50948, a new orally active antiallergic agent, in experimental allergic models. 245 28

Since 2-(diethylamino)-7-methoxychromone (III a) showed remarkable activity in the rat PCA test, some modifications to its structure were made. For instance new substituents such as chlorine or nitro group were introduced into the molecule and the diethylamino group modified. Thus, 2-(ethylamino)-7-methoxychromone (IX) was prepared by treating 3-methoxyphenol with N-ethylethoxycarbonylacetamide in the presence of phosphorus oxychloride. In this case a small amount of 4-chloro-7-methoxycoumarin was also isolated from the reaction mixture. Moreover compounds (XIV), (XV), (XVII) structurally related to sodium cromoglycate were prepared. The pharmacological screening of some compounds showed a useful antiallergic activity.
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PMID:[Chemistry and pharmacology of pyran derivatives. 16. Derivatives of 2-(dialkylamino)-7-methoxychromone with antiallergic activity]. 286 20

Effects of TA-5707F [6-methyl-N-(1H-tetrazol-5-yl)-2-pyridinecarboxamide] and its sodium salt (TA-5707) on IgE-induced homologous PCA in rats were investigated. 1. Both TA-5707 and TA-5707F were found to be orally effective inhibitors of rat PCA. Maximum activity by oral administration was obtained when they were administered 5 min before the challenge. Their ID50's under these conditions were both approximately 1 mg/kg. Administration 5 min after the challenge was no longer effective. 2. TA-5707 was also effective by intravenous administration, and its ID50, ca. 0.1 mg/kg, was less than that of disodium cromoglycate (DSCG). 3. The PCA-inhibitory activity of TA-5707 was not affected by adrenalectomy and adrenomedullectomy. 4. Daily administration of TA-5707 or TA-5707F for 8 days did not induce drug tolerance. 5. Tachyphylaxis and cross-tachyphylaxis were observed when the PCA-inhibitory activities of TA-5707 and DSCG were tested after intravenous pretreatment with a large dose (ca. 30 times the ID50) of either drug, but not after oral pretreatment with a therapeutic dose of TA-5707 or TA-5707F.
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PMID:Studies on a new antiallergic pyridinecarboxamide TA-5707F and its sodium salt (TA-5707). I. Inhibition of IgE-induced passive cutaneous anaphylaxis (PCA) in rats. 293 47

The Malachite Green method for determination of inorganic phosphate (Pi) (Itaya K. & Ui, M. (1966) Clin. Chim. Acta 14, 361-366) was modified to measure Pi in the range of 0.2-15 nmol per ml of ATPase reaction mixture. An ATPase reaction mixture is quenched with an equal volume of 0.6 M PCA; the supernatant after centrifugation is mixed with an equal volume of the Malachite Green/molybdate reagent containing 2 g of sodium molybdate, 0.3 g of Malachite Green and 0.5 g of Triton X-100 or Sterox SE in 1 liter of 0.7 M HCl, and the absorbance at 650 nm is then measured after a 35-40 min incubation at 25 degrees C. Owing to the high sensitivity and simplicity of the modified method, the slow time course of myosin ATP hydrolysis in the presence of Mg2+ and the size of initial phosphate burst can be determined accurately using relatively low concentrations of native myosin and its subfragment-1. The phosphate burst size varied with changes in pH, ionic strength, and temperature. A typical value was 0.8-0.9 mol per site in 0.1 M KCl, 10 mM MgCl2, pH 8.0 at 25 degrees C for fresh enzyme preparations.
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PMID:The initial phosphate burst in ATP hydrolysis by myosin and subfragment-1 as studied by a modified malachite green method for determination of inorganic phosphate. 294 Feb 37

When 13 B cell lines were phenotyped with a panel of B cell, stage-specific monoclonal antibodies and ordered with respect to differentiation state; their sensitivity to natural killer (NK) cell-mediated conjugate formation and cytolysis was found to be stage dependent. Target cell lines expressing an early B cell phenotype (B1+B2-CALLA+DU-ALL1 +/-) or an intermediate phenotype (B1+B2+CALLA-DU-ALL1+) were NK resistant. Late phenotypic B cells (B1+B2-CALLA-DU-ALL1-) were highly susceptible to NK cytolysis. Individual B cell lines when induced with sodium butyrate or retinoic acid expressed altered B cell phenotype and NK susceptibility. For example, SB, an intermediate B cell line and initially NK resistant, when induced to express a later B cell phenotype became NK sensitive. BJA.B, a late B cell line and initially NK sensitive, when induced to differentiate lost most of its sensitivity to natural killing. Since loss of the B2 antigen is associated with B cell activation, we further phenotyped the B cell lines and induced B cell lines with the 4F2 and 5E9 (anti-transferrin receptor) monoclonal reagents. All cell lines tested expressed each of these antigens, but with varying intensities. While the intensity of 4F2 expression appeared to correlate well with NK sensitivity on both resting and differentiated B cell lines, the intensity of 5E9 expression did not. Peripheral blood B cells express a similar pattern of reactivity to natural killing when stimulated with pokeweed mitogen (PWM) in vitro. B cell sensitivity to NK-mediated events peaked at day 4 of incubation and correlated with the loss of the B2 antigen and acquisition of the 4F2 and 5E9 antigens; sensitivity to natural killing was diminished in the presence of the PCA-1 antigen. The expression of the NK-susceptible phenotype among B cells appears to be differentiation stage- and activation state-dependent. It is during this period of ontogeny that the NK cell may cytolytically regulate the B cell transition to a plasma cell.
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PMID:B cell sensitivity to natural killing: correlation with target cell stage of differentiation and state of activation. 308 29


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