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)

The inhibition of the haematological alterations and prevention of death due to systemic anaphylaxis after antigen challenge were investigated in rats after various drug treatments. The i.v. injection of ovalbumin (250 micrograms/kg) into actively sensitized rats induced marked thrombocytopenia and haemoconcentration within 5 min and significant leukocytosis within 30 min, lasting for 2 h after the challenge. Pretreatment with meclizine or terfenadine (15-30 mg/kg i.p.) inhibited antigen-induced haemoconcentration, whereas WEB 2086 (2-10 mg/kg i.p.) and PCA 4248 (5-10 mg/kg p.o.), two platelet-activating factor (PAF) antagonists, interfered with thrombocytopenia only. Azelastine (1-20 mg/kg p.o.) dose dependently inhibited antigen-induced haemoconcentration and thrombocytopenia but failed to block leukocytosis. Azelastine also inhibited the thrombocytopenia observed after the i.v. administration of PAF (4 micrograms/kg). Administration of ovalbumin at a dose of 1.5 mg/kg resulted in a lethal anaphylactic reaction in about 85% of the rats. Pretreatment with WEB 2086 (10 mg/kg i.p.), meclizine (30 mg/kg i.p.) or both increased the survival rate from 15 to 57, 68 and 87%, respectively. Azelastine alone (20 mg/kg p.o.) completely blocked the lethal reaction. It was concluded that the ability of azelastine to antagonize histamine and PAF is important for its effectiveness against anaphylactic shock.
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PMID:Interference of azelastine with anaphylaxis induced by ovalbumin challenge in actively sensitized rats. 135 32

We studied the effects of OKY-046 on type I allergic reactions. OKY-046 (100 mg/kg) given orally suppressed antigen-induced bronchoconstriction and TXB2 generation in broncho alveolar lavage fluid in rats passively sensitized with anti-DNP-As monoclonal IgE. At the dose of 30 mg/kg given intraduodenally, it also inhibited antigen-induced bronchoconstriction in guinea pigs passively sensitized with anti DNP-As serum and actively sensitized with ovalbumin. However, aspirin (30 mg/kg) didn't suppressed them significantly. Azelastine (10 mg/kg) inhibited bronchoconstriction in passively sensitized rats and actively sensitized guinea pigs. In 48 hour homologous PCA reactions of rats and mice, oral administration of OKY-046 (300 mg/kg) and tranilast (100 mg/kg) suppressed the extravasated dye in the skin. OKY-046 decreased histamine release from passively sensitized rat peritoneal exudate cells. There was no effect of OKY-046 on SRS-A and leukotriene release from actively sensitized guinea pig lungs and passively sensitized rats. In conclusion, we think that OKY-046 should be an useful asthmatic drug or anti-allergic drug by oral administration.
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PMID:[Anti-allergic effects of (E)-3-[p-(1H-imidazol-1-lylmethyl) phenyl]-2-propenoic acid (OKY-046), a specific thromboxane (TX) A2 synthetase inhibitor: effects on type I allergic reactions]. 169 6