Background Topical application of L–arginine, the precursor of nitric oxide, reduces anal resting pressure without significant side effects and may therefore be of benefit in the treatment of anal fissure. This in vivo study investigated the effect of orally administered L–arginine on anal resting pressure and anodermal blood flow in healthy volunteers.
Methods Eight healthy volunteers took 3 sachets of Arginaid (Novartis Consumer Health, Breda, The Netherlands) containing 15 g L–arginine on a daily basis, for 7 days. At the start of the experiment (day 0) and on days 3 and 7, plasma levels of Larginine, anal resting pressures and anodermal blood flow were determined.
Results Arginine plasma levels increased from 107.0±8.6 μmol/l (day 0) to 283.7±44.0 μmol/l on day 3 (p< 0.01) and remained elevated at day 7 (157.3±19.6 μmol/l, p<0.05). Anodermal blood flow and anal resting pressures were similar on days 0, 3 and 7.
Conclusions Oral administration of 15 g arginine in healthy volunteers on a daily basis increased arginine plasma levels but had no influence on anodermal blood flow and anal resting pressure.