Objective To study the differences in nitric oxide (NO) release and endotheliumderived hyperpolarizing factor (EDHF)mediated hyperpolarization among human internal mammary artery (IMA), radial artery (RA), and sephenous vein (SV) by direct measurement of the signal of NO and membrane potential. Methods The present study was divided into four gro
ups: IMA (n=15), RA (n=6), SV (n=23), and surgically prepared SV group
(dilatation with normal saline solution at a pressure of 100600 mm Hg, PV, n=9). All vascular segments taken from 29 patients undergoing coronary artery
bypass grafting between October 2009 and September 2010 in the Fu 〖CM(159mm]W
ai Hospital Beijing. The vascular segments were placed in an organ chamber
, and the NOsensitive electrode and intracellular glass microelectrode were used to directly measure the NO release and membrane potential changes in response to acetylcholine (ACh) and bradykinin (BK) before and after incubation with NGnitroLarginine, indomethacin, and oxyhemoglobin. Results (1)The basal releas
e of NO in IMA group was 16.8±1.6 nmol/L, n=13, significantly greater than
that in SV group (9.9±2.8 nmol/L, n=13, P lt;0.05) and RA group (11.9±1
.8 nmol/L, n=6, P lt;0.05). Compared with SV group, NO basal release in RA
group was greater (P lt;0.05). (2)The AChinduced NO release was greater in IM
A group than in RA group or SV group, while BKinduced NO release was greater i
n SV group than in RA group. (3) Both basal(3.4±1.4 nmol/L, n=9, P lt;0.05
) and ACh, and BKinduced NO release in PV group were significantly reduced.(
4) EDHFmediated hyperpolarization was greater in IMA group than in SV group or
RA group ［ACh -5 log M: -9.4±1.5 mV(n=10) vs. -4.5±1.1 mV(n=17), -9.7±1.9 mV(n=6), P lt;0.05；BK -7 log M: -10.9±1.5 mV(n=8) vs. -5.1±0.5 mV(n=8), RA -5.8±0.9 mV(n=6), P lt;0.05). Compare with SV group AChinduced EDHFmediated hyperpolarization in RA group was greater(ACh -5 log M:-9.7±1.9 mV, n=6, vs. -4.5±1.1 mV, n=17, P lt;0.01). Conclu
sions (1) IMA is superior to RA and SV in terms of NO basal and stimula
ted release and EDHFmediated hyperpolarization. (2) Compared with SV, both NO
basal release and EDHFmediated hyperpolarization in RA were significantly grea
ter. (3) After surgical preparation and pressure dilatation, both basal and stim
ulated release of NO in SV were severely impaired.

Citation： Differences in Nitric Oxide Release and Endotheliumderived Hyperpolarizing Factormediated Hyperpolarization Among Human Internal Mammary Artery,Radial Artery,and Sephenous Vein. 人体乳内动脉、桡动脉与大隐静脉内皮细胞一氧化氮和超极化因子的差异及其临床意义. Chinese Journal of Clinical Thoracic and Cardiovascular Surgery, 2011, 18(6): 487-. doi: Copy