the r ( - ) - and s ( + ) -enantiomers of alpha-hydroxytolazoline , the benzylic hydroxy-substituted derivative of the alpha-adrenoceptor antagonist , tolazoline , were evaluated at alpha 1- and alpha 2-adrenoceptors in canine saphenous vein .
C0034784
alpha-adrenoceptor
C0001639
alpha 2-adrenoceptors