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)

RU 31156, the tris-(hydroxymethyl)-aminomethane salt of 7-(S-methylsulphonimidoyl)-5-(n-hexyl)-xanthen-9-one-2-carboxylic acid has been found to be a potent inhibitor of experimental immediate hypersensitivity reactions in vivo. In the IgE-mediated rat PCA test, RU 31156 had an ED50 of 0.0046 (00037--0.0057) mg/kg which compared to a figure of 1.21 (1.04--1.42) mg/kg for disocium cromoglycate (DSCG), both compounds being administered intravenously. RU 31156 was also active when administered orally, having an ED50 of 0.19 (0.07--0.30) mg/kg when given 10 min before antigen. RU 31156 partially inhibited an IgG-mediated PCA reaction in the rat. Both RU 31156 and DSCG inhibited anaphylactic bronchoconstriction in the rat, giving bell-shaped dose-response curves. From the upward part of the curves, approximate ED30 values of 0.02 and 2.0 mg/kg were obtained for RU 31156 AND DSCG respectively. Anaphylactic bronchoconstriction in the guinea-pig was not affected by RU 31156 and pinnal anaphylaxis was inhibited at only relatively high doses of 1--10 mg/kg i.v. The effects of both histamine and 5-hydroxytryptamine in the mouse pinna were not affected by RU 31156. In PCA experiments, RU 31156 showed self-tachyphylaxis following both intravenous and oral administration. It also showed cross-tachyphylaxis with DSCG, indicating that these compounds are likely to share a similar mode of action.
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PMID:Inhibition of experimental immediate hypersensitivity reactions by a novel xanthone, RU 31156. 2 34

Two platinum (Pt) refinery workers with work related asthma was reported. The serum specific IgE and skin test for Pt antigen were positive. Ten guinea pigs were immunized with Pt-BSA conjugates employing CFA or AHG adjuvant via intraperitoneal. After 5-8 weeks, 33.3% of the sensitized animals experienced asthma attacks after a Pt-HSA challenge. The dynamic ventilation pulmonary imaging with 99mTc-DTPA showed a central accumulation of radioactivity. A specific IgE and IgG type antibodies were developed in 66.7% of sensitized animals by PCA test. Results of these suggested that platinum complex salt have antigenic specify. Allergic response play an important role in the mechanism of Pt induced asthma.
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PMID:[A study on the immunology and etiology of platinum induced asthma]. 181 74

In these experiments we characterize the protective antibodies in immune serum that interact synergistically with immune thoracic duct lymphocytes (TDL) to induce rapid expulsion (RE) of Trichinella spiralis in adult rats. Antibodies with both reaginic and nonreaginic activity mediated RE upon passive transfer to adult rats that had been adoptively transfused with immune TDL 7 days earlier. In serum collected 28 days after a primary infection, the most important antibody was homocytotropic IgE. Native IgE produced by active infection was isolated from 28-day immune serum by salt precipitation and/or by sequential affinity chromatography. The murine mAb A2 and B5 (anti-rat IgE) were conjugated separately to Sepharose 4B affinity columns for affinity separations. IgE was shown to be pure by gel electrophoresis and Western blots and its m.w. was estimated at approximately 190,000. As little as 183 micrograms of purified IgE could induce RE after passive transfer to adult rats. The IgE was shown to be functional by PCA activity, Ag-binding on Western blots, and skin sensitization; the latter could be blocked by pretreatment with 1R162, a rat myeloma IgE. Monoclonal IgG of any isotype transferred in amounts up to 35 mg/rat could not transfer RE to rats previously transfused with TDL cells. Immune serum collected 3 mo after the primary infection contained insufficient IgE to transfer RE, but complex non-IgE fractions were protective. The data thus demonstrate that IgE is a functional Ig in the rat capable of mediating the rejection of challenge nematode infections of the gut in the absence of other specific Ig. Secondly, other Ig may also play a role, in particular, several weeks after the primary infection when specific IgE levels in serum have declined.
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PMID:A role for IgE in intestinal immunity. Expression of rapid expulsion of Trichinella spiralis in rats transfused with IgE and thoracic duct lymphocytes. 202 81

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

In the present report we describe the preparation of LC-6.2HCl, a soluble derivative of the synthetic bispyrazole LC-6. Because the latter was practically insoluble in aqueous and organic media, experiments which indicated that it had antiallergic activity were confined to in vivo studies following its oral administration. The availability of soluble LC-6.2HCl made it possible to administer the drug i.v. or i.p. Through these routes it exhibited greater antiallergic activity than by the oral route, as judged by lower ID50's and by the achievement of 100% PCA inhibition. The latter result had not previously been attained orally with the base. Furthermore, when injected i.v. or i.p. LC-6.2HCl showed prolonged inhibitory activity, a valuable attribute of the parent compound. The in vivo activity of the soluble salt, which we describe, further establishes the potential therapeutic value of the drug.
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PMID:Preparation and evaluation of a soluble derivative of the antiallergic compound trans-2, 3b, 4, 5, 7, 8b, 9, 10-octahydronaphtho [1, 2-c:5, 6-c'] dipyrazole (LC-6). 286 22

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 effects of the arginine salt of pyroglutamic acid (2-oxo-pyrrolidone carboxylic acid, PCA) on learning and memory capacities of old rats were studied in a subchronic treatment schedule (i.p. injection of 0.1 and 1 g/kg/day for 15 days). The acquisition and extinction of active avoidance behaviour were studied in a pole-jumping test situation. The retention of passive avoidance response was examined in a step-through passive avoidance task. PCA facilitated the rate of acquisition of pole-jumping response, and inhibited the extinction of the response. The dose of 1 g/kg was more potent than 0.1 g/kg in this respect. Also in the passive avoidance task, the treatment with PCA was followed by an improvement of avoidance retention. These results indicate that PCA is a behaviourally active compound in that it improves learning and memory capacities in old rat.
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PMID:Pyroglutamic acid improves learning and memory capacities in old rats. 340 13

The acquisition of a passive avoidance conditioned response was disrupted in the rat by electroconvulsive shock (ECS) and scopolamine administration. D,L-pyroglutamic acid (D,L-PCA) 500 and 1000 mg/kg, administered as arginine salt 120 min before the retest, prevented both the ECS and scopolamine-induced amnesia. Arginine alone was ineffective. Scopolamine brought about a 52 and 39% decrease, respectively, in cortical and hippocampal acetylcholine (ACh) levels, measured by means of a gas-chromatographic method. D,L-PCA 500 and 1000 mg/kg also prevented the decrease in brain ACh level. When the two isomers were studied separately, D-PCA was more effective than L-PCA and antagonized scopolamine-induced amnesia at the doses of 250 and 500 mg/kg. In conclusion, D,L-PCA is active on cortical and hippocampal cholinergic mechanisms and, like other 2-oxopyrrolidone derivatives, shows cognition-enhancing properties.
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PMID:Effect of pyroglutamic acid stereoisomers on ECS and scopolamine-induced memory disruption and brain acetylcholine levels in the rat. 344 11

Ammonium tetrachloroplatinate II ([NH4]2 PtCl4) was used in free and conjugated forms with ovalbumin in an attempt to elicit specific antibody directed against either the free platinum (Pt) salt or the platinum moiety of ovalbumin-Pt conjugates in the hooded Lister rat. Immunization with free Pt salt via intraperitoneal, intramuscular, intradermal, subcutaneous, intratracheal and footpad routes over a wide range of doses (1 microgram-1 mg) employing both B. pertussis and/or aluminium hydroxide gel as adjuvants failed to induce specific IgE antibody, either primary or secondary, as shown by direct skin, PCA test or RAST. Conjugation of (NH4)2 PtCl4 with ovalbumin produced conjugates, with between two and 10 haptenic Pt groups per ovalbumin molecule, capable of inducing IgE antibody directed against the Pt moiety as determined by heterologous PCA challenge, where carrier cross-reactivity was excluded, and by specific RAST, confirmed by RAST inhibition.
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PMID:Immunological responses to complex salts of platinum. I. Specific IgE antibody production in the rat. 674 66

A series of N-(4-substituted-thiazolyl)oxamic acid derivatives were synthesized and tested for antiallergy activity in the rat PCA model. These compounds were conveniently prepared by treatment of the appropriate acetophenone with thiourea and iodine or by reaction of the chloroacetylbenzene with thiourea to give the corresponding aminothiazoles; subsequent condensation with ethyloxalyl chloride gave the thiazolyloxamates. Many of the analogues showed a 50% inhibition at less than 2 mg/kg po or less than 0.4 mg/kg iv and were significantly more potent than disodium cromoglycate, which in the rat PCA model is orally inactive and gives a 50% inhibition at 1.2 mg/kg iv. Hydrolysis of the oxamates generally resulted in enhanced activities, while substitution of the phenyl ring with a variety of substituents (e.g., 4-F, 4-OEt, and 4-NHCOCH3) did not significantly enhance the activity of the unsubstituted phenyl derivative. One of the ethanolamine salts, N-[4-(1,4-benzodioxan-6-yl)-2-thiazolyl]oxamic acid ethanolamine salt (61, PRH-836-EA), has been selected for further pharmacological evaluation.
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PMID:N-(4-substituted-thiazolyl)oxamic acid derivatives, a new series of potent, orally active antiallergy agents. 687 84


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