this increased airway sensitivity was not due to beta-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 beta-adrenoceptor blockade in the airways .
C0001643
beta-adrenoceptor
C0034783
adrenoceptor