Related Experiment Video
Updated: Oct 13, 2026

Intradermal Microdialysis: An Approach to Investigating Novel Mechanisms of Microvascular Dysfunction in Humans
Published on: July 21, 2023
A novel S-nitrosothiol (RIG200) causes prolonged relaxation in dorsal hand veins with damaged endothelium
N Sogo1, I B Wilkinson, H MacCallum
1Clinical Pharmacology Unit and Research Centre, University of Edinburgh, Western General Hospital, Scotland.
Background:
Reduced nitric oxide bioavailability caused by endothelial dysfunction or damage is a contributory factor in the initiation and progression of a number of cardiovascular diseases. Delivery of exogenous nitric oxide is an attractive therapeutic option, but current agents lack selectivity for areas of endothelial damage. We tested the hypothesis that a novel nitric oxide donor drug, N-(S-nitroso-N-acetylpenicillamine)-2-amino-2-deoxy-1,3,4,6-tetra-O-acet yl-P-glucopyranose [RIG200], which has selective effects in endothelium-denuded isolated arteries in vitro, would exert similar effects in dorsal hand veins with experimentally damaged endothelium in vivo.
Methods:
Venodilator responses to sodium nitroprusside and RIG200 were compared in two groups of healthy volunteers (age range, 18 to 63 years; n = 7 for each group) in norepinephrine 70% maximum effective concentration (EC70) preconstricted hand veins with use of the Aellig technique. In this doubleblind study, subjects were randomly assigned to receive either sodium nitroprusside or RIG200 (infusions of 0.06 and 6 nmol/min into the hand vein) before and 2 days after 15 minutes of local venous irription with distilled water. Endothelial function was assessed in all subjects on both visits with use of the endothelium-dependent vasodilator acetylcholine (1 nmol/min).
Results:
Irrigation of hand veins with distilled water abolished endothelium-dependent dilatation in response to acetylcholine in both study groups (n = 14) but did not affect the amplitude or duration of responses to the conventional nitric oxide donor sodium nitroprusside (P = .87; n = 7). However, responses to RIG200 were significantly prolonged during the washout phase (30 minutes) in veins after water irrigation (P = .02; n = 7).
Conclusion:
These studies confirm that RIG200 has prolonged effects in veins with damaged endothelium, a characteristic that might be exploited therapeutically to target nitric oxide delivery to damaged blood vessels.
More Related Videos
Related Concept Videos
Nitric Oxide Signaling Pathway
Antihypertensive Drugs: Vasodilators
2° Amines to N-Nitrosamines: Reaction with NaNO2
Antianginal Drugs: Nitrates and β-Blockers
Organic nitrates, such as nitroglycerin, play a pivotal role. Once metabolized, they liberate nitric oxide, a molecular marvel. Nitric oxide triggers guanylyl cyclase and augments cGMP production. This biochemical cascade orchestrates the relaxation of vascular smooth muscles, ushering in vasodilation and enhancing coronary blood flow. Administered...
Antianginal Drugs: Calcium Channel Blockers and Ranolazine
CCBs, a diverse class that includes dihydropyridines (nifedipine) and diphenylalkylamines (verapamil and diltiazem), exert their effect by blocking calcium channels in cardiac and smooth muscle cells. This...
Vascular Spasm

