Figure 1. Coronary microvascular response to serotonin in vitro.
A. Diameter of microvessels before pre-contraction. There was no difference in baseline vessel diameter among the groups (p=0.4).
B. Diameter of microvessels after pre-contraction. Vessels were pre-contracted with U46619, a thromboxane A2 analog. There was no difference among the groups prior to addition of serotonin (p=0.31).
C. Serotonin response of vessels harvested before CP-CPB with and without selective 5-HT1B receptor blocker, SB224289. SB224289 administered in the presence of 5HT to the pre-CP-CPB microvessels resulted in a response similar to the 5HT alone (p= 0.44).