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Propranolol‐induced airway hyperreactivity in guinea‐pigs
Author(s) -
Ney U.M.
Publication year - 1983
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1111/j.1476-5381.1983.tb10548.x
Subject(s) - propranolol , bronchoconstriction , practolol , histamine , bronchospasm , antagonist , leukotriene , pharmacology , leukotriene d4 , chemistry , medicine , endocrinology , anesthesia , airway , asthma , receptor
1 In anaesthetized, spontaneously breathing guinea‐pigs, enhanced bronchoconstrictor responses (↑ R L ) to histamine were measured following intravenous injection of practolol, (±)‐propranolol, (+)‐ and (−)‐propranolol. 2 Propranolol enhanced not only histamine‐ but 5‐hydroxytryptamine (5‐HT)‐induced bronchoconstrictions and its effects lasted up to 2 h. 3 This increased airway sensitivity was not due to β‐adrenoceptor blockade because: (a) similar effects were produced by racemic propranolol and its two isomers (+)‐ and (−)‐propranolol and (b) whilst equal doses of (±)‐ and (+)‐propranolol produced the same potentiation of histamine bronchoconstriction, only (±)‐propranolol also caused a measurable β‐adrenoceptor blockade in the airways. 4 The enhanced histamine‐ and 5‐HT‐induced bronchoconstrictions were antagonized by the leukotriene antagonist FPL 55712 and by the lipoxygenase/cyclo‐oxygenase inhibitor BW755c. 5 The results demonstrate that endogenously released leukotrienes can produce not only a direct bronchospasm but may enhance the effects of other bronchoconstrictor agents. 6 The relevance of this leukotriene‐mediated hyperreactivity to the non‐specific airway hyperreactivity seen in asthmatics is discussed.