First evaluation of real-time nitric oxide changes in the coronary circulation in patients with non-ischaemic dilated cardiomyopathy using a catheter-type sensor.
OBJECTIVE
No direct method has yet been developed to measure real-time plasma nitric oxide (NO) concentration in humans. In this study, we evaluated a new method for measuring plasma NO concentration in patients with dilated cardiomyopathy (DCM) and in normal controls using a catheter-type sensor.


RESULTS
We simultaneously measured average peak velocity (APV) of the coronary artery flow and change in plasma NO concentration using the NO sensor placed in the great cardiac vein of 10 DCM patients and 10 control subjects. These evaluations were performed in response to sequential intracoronary infusions of acetylcholine (ACh, 10⁻⁸-10⁻⁶ M), N(G)-monomethyl-l-arginine (l-NMMA, 200 µmol) and co-infusion of ACh and l-NMMA. The change in plasma NO concentration in DCM patients was significantly impaired compared with the control group (P < 0.01). Pretreatment with l-NMMA completely suppressed the ACh-induced NO concentration, whereas APV in the left anterior descending coronary artery was partially suppressed in both groups. Plasma NO concentration reached its peak value later than the maximum APV following the injection of ACh (10⁻⁶ M) in both groups.


CONCLUSIONS
The catheter-type NO sensor could be applied to clinically evaluate the endothelial function (i.e. reduced endothelium-derived NO bioavailability) in patients with cardiovascular diseases.
Department of Cardiovascular Medicine, Wakayama Medical University, 811-1 Kimiidera, Wakayama 641-8509, Japan.
Shigeho
S
Takarada
Toshio
T
Imanishi
Masami
M
Goto
Seiichi
S
Mochizuki
Hideyuki
H
Ikejima
Hiroto
H
Tsujioka
Akio
A
Kuroi
Tatsuya
T
Takeshita
Takashi
T
Akasaka
D000109:Acetylcholine / Q000494:pharmacology; D000328:Adult; D000368:Aged; D001783:Blood Flow Velocity / Q000187:drug effects; D006328:Cardiac Catheterization / Q000295:instrumentation*; D002311:Cardiomyopathy, Dilated / Q000503:physiopathology*; D017023:Coronary Angiography; D003326:Coronary Circulation / Q000502:physiology*; D003331:Coronary Vessels / Q000187:drug effects; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000096:biosynthesis / Q000097:blood*; D014664:Vasodilation / Q000187:drug effects; D014665:Vasodilator Agents / Q000494:pharmacology; D019323:omega-N-Methylarginine / Q000494:pharmacology
D014665:Vasodilator Agents; D019323:omega-N-Methylarginine; D009569:Nitric Oxide; D000109:Acetylcholine