augmented responses of the coronary artery to histamine , but not to phenylephrine or potassium chloride were reproduced in the nonbeating isolated heart preparations perfused at 90 mm hg with oxygenated krebs-henseleit solution , and the degree and location of in vitro hyperconstriction were similar to that in vivo and were not attenuated after pretreatment with the nerve transmitter blockers , guanethidine ( 3 x 10 ( -6 ) m ) , atropine ( 10 ( -6 ) m ) and tetrodotoxin ( 3 x 10 ( -7 ) m ) .
C0205042
coronary artery
C0018787
heart