These tools will no longer be maintained as of December 31, 2024. Archived website can be found here. PubMed4Hh GitHub repository can be found here. Contact NLM Customer Service if you have questions.


Pubmed for Handhelds

PUBMED FOR HANDHELDS

Search MEDLINE/PubMed

  • Title: Inhibition of the platelet activating factor mediated component of guinea pig anaphylaxis by receptor antagonists.
    Author: Darius H, Smith JB, Lefer AM.
    Journal: Int Arch Allergy Appl Immunol; 1986; 80(4):369-75. PubMed ID: 3015804.
    Abstract:
    The role of platelet activating factor (PAF) and its inhibition by specific receptor antagonists was studied in hypersensitivity reactions in guinea pig lung parenchymal strips and in guinea pigs in vivo. Immunological challenge of isolated lung parenchymal strips with ovalbumin resulted in a contractile response of 184 +/- 16 mg (n = 38). Pretreatment of the strips with a combination of the antihistamine diphenhydramine, the dual lipoxygenase and cyclooxygenase product synthesis inhibitor BW-755C, and the PAF receptor antagonist kadsurenone totally inhibited the increase in tension. The bronchoconstrictor effects induced by immunological challenge were also totally inhibited when the leukotriene receptor antagonist FPL-55,712 was used to replace BW-755C or another PAF receptor antagonist, alprazolam was used to replace kadsurenone. Ovalbumin challenge in sensitized guinea pigs in vivo resulted in airway constriction, circulatory failure and an abrupt fall in continuously measured platelet count by 75 +/- 12%, followed by death of all animals within 5-8 min. Pretreatment with diphenhydramine, BW-755C and kadsurenone (or alprazolam) improved survival to 64% (i.e., 7 of 11 animals) compared to a survival rate of 0% (i.e., 0 of 8 vehicle treated controls). Despite the improved survival, the severe thrombocytopenia was unaltered with the combined therapy. PAF, histamine and peptide leukotrienes appear to act in concert in mediating the anaphylaxis-induced airway constriction and circulatory failure in guinea pigs, but are not apparently responsible for the accompanying thrombocytopenia.
    [Abstract] [Full Text] [Related] [New Search]