Purchase this article with an account.
Lars-Olof Hattenbach, Agnieszka Allers, Christina Klais, Frank Koch, Markus Hecker; l-Arginine–Nitric Oxide Pathway–Related Metabolites in the Aqueous Humor of Diabetic Patients. Invest. Ophthalmol. Vis. Sci. 2000;41(1):213-217.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
purpose. Nitric oxide (NO) is an important signal-transduction
molecule that plays a significant role in the regulation of
cardiovascular functions. In the l-arginine–NO pathway, NO
synthase (NOS) converts l-arginine (l-Arg), the
only known biologic substrate for NO formation, to NO and l-citrulline (l-Cit). Excessive NO production
mediated by the inducible isoform of NOS has been implicated in the
pathogenesis of various diseases. In the present study it was
hypothesized that in vitreoretinal disorders such as diabetic
retinopathy the production of l-arg–NO pathway–related
metabolites may be upregulated as a result of increased NO generation.
methods. From 20 eyes of nondiabetic subjects and 22 eyes of diabetic patients
with (n = 14) and without (n = 8)
diabetic retinopathy, undiluted samples of aqueous humor were drawn
before cataract surgery. Levels of l-arg, l-Cit, and the specific NOS by-product
NG-hydroxy-l-arginine (HOArg) were measured by
high-performance liquid chromatography.
results. l-Arg, l-Cit, and HOArg were detected in all
aqueous humor samples from diabetic and nondiabetic patients (n= 42). Comparison of HOArg levels in nondiabetic and diabetic
subjects showed significantly higher levels in diabetic patients
(P = 0.002). Concentrations of HOArg were higher in
samples from patients with (P = 0.005) and without
diabetic retinopathy (P = 0.033) than in control
subjects. No statistically significant differences were observed in l-Arg or l-Cit levels.
conclusions. Elevated levels of HOArg in the aqueous humor of diabetic
patients reflect the possible role of NO as a significant factor in the
regulation of retinal vascular functions and intraocular proliferative
changes in diabetes mellitus in vivo. The control of intraocular NO
production may constitute a potential therapeutic approach in diabetic
This PDF is available to Subscribers Only