PURPOSE: Demonstrate unequivocally the generation of nitric oxide in experimental autoimmune uveoretinitis by electron spin resonance spectroscopy (ESR) using ferrous iron complex of N-methyl-D-glucamine dithiocarbamate, (MGD)2-Fe2+, as a spin trap. METHODS: Experimental autoimmune uveitis was induced in Lewis rats, and at the peak of the intraocular inflammation, the animals received intravitreous injections of the spin trap. The retina and choroid dissected from the enucleated globes were subjected to ESR. Similarly, the retina and choroid obtained at the peak of experimental autoimmune uveo-retinitis (EAU) were placed in a vial containing luminal, and chemiluminescence was counted on a Packard liquid scintillation analyzer. RESULTS: The ESR three-line spectrum (g=2.04; a(N)=12.5 G) obtained was characteristic of the adduct [(MGD)2-Fe2+-NO]. The majority of this signal was eliminated by the inducible nitric oxide synthase (iNOS) specific inhibitor aminoguanidine injected inflamed retina was detected when compared with that of the non inflamed controls. The chemiluminescent activity was further increased two-fold by the addition of bicarbonate to the inflamed retina; the phenomenon is attributable only to the presence of a high steady-state concentration of peroxynitrite. CONCLUSIONS: The study shows an unequivocal presence of nitric oxide in EAU retina and choroid and the generation of peroxynitrite. High levels of these reactive nitrogen species generated in the inflamed retina and choroids are certain to cause irreversible tissue damage, especially at the susceptible sites such as photoreceptors.
Uveitis/immunology/*metabolism ; Thiocarbamates ; Spin Trapping ; Spin Labels ; Sorbitol/analogs & derivatives ; Retina/metabolism ; Reactive Nitrogen Species/*metabolism ; Rats, Inbred Lew ; Rats ; Peptide Fragments/immunology ; Humans ; Electron Spin Resonance Spectroscopy ; Choroid/metabolism ; Autoimmune Diseases/immunology/*metabolism ; Arrestin/immunology ; Animals

OBJECTIVETo assess the therapeutic effect of losartan on type 2 diabetes mellitus (DM2) with gas chromatography (GC)-based metabonomics.

METHODSDM2 patients were dosed with losartan (100 mg/d) and urines were collected at week 8 and 12. The biochemical criteria (blood pressure, urinary albumen, urinary 8-hydroxy-2'-deoxyguanosine and blood creatinine) were analyzed. Urine samples were derivatived and analyzed by GC. Multivariate metabonomics analysis was performed after peak alignment.

RESULTSAfter 8-12 weeks, losartan showed little curative effect and no remarked changes of biochemical criteria were observed. However, metabonomics analysis revealed that some biomarkers such as glucitol and inositol changed.

CONCLUSIONGC-based metabonomics analysis enables the rapid identification of metabolic differences and provides information concerning therapeutic effect of losartan.

Albuminuria ; urine ; Biomarkers ; blood ; chemistry ; urine ; Chromatography, Gas ; methods ; Creatinine ; blood ; Deoxyguanosine ; analogs & derivatives ; urine ; Diabetes Mellitus ; drug therapy ; Diabetes Mellitus, Type 2 ; drug therapy ; Drug Monitoring ; Humans ; Hypoglycemic Agents ; therapeutic use ; Inositol ; chemistry ; Losartan ; therapeutic use ; Metabolome ; drug effects ; Sorbitol ; chemistry