eNOS 894T allele and coronary blood flow at rest and during adenosine-induced hyperemia

The 894T allele of a G894T polymorphism in the endothelial nitric oxide syn thase (eNOS) gene is associated with decreased eNOS activity, cleavage of t he protein, and endothelial dysfunction. The present study evaluated the as sociation with coronary blood flow (CBF) at rest and during adenosine (ADO) -induced hyperemia. CBF was determined by Doppler flow wire and angiography in 97 left anterior descending arteries of individuals without coronary ar tery disease. At rest, average peak velocity (APV) was lower and coronary v ascular resistance (CVR) was higher in homozygous carriers of the 894T alle le than in heterozygotes and individuals without the 894T allele. CBF tende d to be lower in eNOS 894T allele carriers. During ADO-induced hyperemia (1 8 mug ic), APV, CVR, and CBF were not statistically different between the g enotypes. The reduced APV at rest in conjunction with an increased CVR indi cates a vasomotor dysfunction related to an increased microvascular resting tone in eNOS 894T allele carriers.