the addition of 1-epinephrine or 1-norepinephrine ( 1 microgram/ml ) to the perfusion medium for 1 h caused visible and irreversible morphological changes which usually became apparent after 4 h of perfusion in the form of small , pale , opaque spots or streaks gradually enlarging on the surface or on the cross-section area of the myocardium .
C0014563
epinephrine
C0028351
norepinephrine