Pharmacological response of internal mammary artery and gastroepiploic artery.

Pharmacological response of coronary artery bypass conduit is of great importance. This study was designed to clarify the contractile properties of internal mammary artery and gastroepiploic artery obtained from coronary revascularization. The response to ergonovine, serotonin, and phenylephrine was examined by isometric contraction recording apparatus. The concentration-response relation of both internal mammary artery and gastroepiploic artery to ergonovine, serotonin, and phenylephrine showed similar sigmoid curves. There were no significant differences in developed tension between internal mammary artery and gastroepiploic artery at any concentration for any agent. There were no significant differences in the 50% effective dose value for any agent between internal mammary artery and gastroepiploic artery. Internal mammary artery and gastroepiploic artery are reported to be similar in terms of size, flow capacity, and freedom from atherosclerosis. This study shows their equivalence from a pharmacological viewpoint.