ß2 Adrenergic Receptor Polymorphisms and Vasodilation of Internal Mammary Artery Induced by Isoproterenol

Single nucleotide polymorphisms at codon 46 and 79 of the gene encoding for the ß2 adrenergic receptor (ß2AR) modify its pharmacological properties and may alter the response to ß2AR agonists. The goal of the present study was to evaluate the role played by the Arg16Gly and Gln27Glu polymorphisms on isoproterenol induced relaxation of internal mammary arteries segments ex-vivo.

Internal mammary leftover segments were collected from 96 patients undergoing coronary artery bypass graft operation. Four rings that were prepared from each specimen were allowed to reach equilibrium with physiological Krebs solution prior to precontraction with U46619. Using the organ bath technique, cumulative dose response curve of isoproterenol was constructed and mean EC50 calculated for each patient.