cysteinylglycine and Retinal-Vein-Occlusion

Our aim was to determine the plasma levels of the sulfur-containing amino acids homocysteine, cysteine, cysteinylglycine, glutamylcysteine, glutathione and taurine in patients with branch retinal vein occlusion (BRVO) and in healthy subjects and to ascertain whether there are statistically significant differences between patients and controls.. Homocysteine, cysteine, cysteinylglycine, glutamylcysteine, glutathione and taurine plasma levels were measured in 40 patients with BRVO and 80 age- and gender-matched control subjects by using laser-induced fluorescence capillary electrophoresis methods. Wilcoxon's or Student's t test was used, when appropriate, to determine differences between the groups. Conditional logistic regression analysis was performed to determine the risk factors for BRVO.. BRVO patients showed significantly lower plasma concentrations of cysteinylglycine (p = 0.02) and taurine (p < 0.0001) than controls. Conversely, there were no significant differences in plasma homocysteine, cysteine, glutamylcysteine and glutathione between patients with BRVO and controls. Conditional logistic regression analysis revealed an odds ratio of 0.95 (95% confidence interval: 0.92-0.98, p = 0.001) for taurine and 0.86 (95% confidence interval: 0.78-0.96, p = 0.006) for cysteinylglycine.. This study failed to demonstrate an association between BRVO and the plasma levels of homocysteine, cysteine, glutamylcysteine and glutathione. Cysteinylglycine and taurine were significantly lower in BRVO patients, thus suggesting that reduced plasma levels of these sulfur-containing amino acids may contribute to the pathogenesis of BRVO.

Topics: Age Factors; Aged; Aged, 80 and over; Case-Control Studies; Cysteine; Dipeptides; Electrophoresis, Capillary; Female; Glutathione; Homocysteine; Humans; Male; Middle Aged; Retinal Vein Occlusion; Risk Factors; Taurine

To determine the plasma levels of the sulfur-containing amino-acids homocysteine, cysteine, cysteinylglycine, glutamylcysteine, glutathione, and taurine in patients with central retinal vein occlusion (CRVO) and in healthy subjects and to ascertain whether there are statistically significant differences between patients and controls.. Laser-induced fluorescence capillary electrophoresis was used to measure the plasma levels of homocysteine, cysteine, cysteinylglycine, glutamylcysteine, glutathione, and taurine in 29 patients with CRVO and 80 age- and gender-matched control subjects. Wilcoxon or Student's t-test was used, when appropriate, to determine differences between groups. Multivariate logistic regression analysis was used to determine the risks for CRVO.. CRVO patients showed significantly higher concentrations of cysteine (p = 0.032) and significantly lower concentrations of cysteinylglycine (p = 0.009) and taurine (p = 0.0002) than controls. Conversely, there were no significant differences in plasma homocysteine, glutamylcysteine, and glutathione between CRVO patients and controls. When categorized by CRVO type (ischemic/non-ischemic), taurine was still lower in both subgroups than in controls, whereas cysteine, cysteinylglycine, as well as homocysteine, were significantly higher only in the ischemic subgroup. In non-ischemic CRVO, cysteinylglycine fell just short of statistical significance (p = 0.06). Logistic regression analysis revealed an odds ratio of 1.02 (95% confidence interval (CI): 1.01-1.04, p = 0.001) for cysteine, 0.79 (95% CI: 0.70-0.89, p = 0.0002) for cysteinylglycine, and 0.94 (95% CI: 0.90-0.97, p = 0.002) for taurine.. Results suggest that reduced plasma levels of cysteinylglycine and taurine may contribute to the pathogenesis of both CRVO types. Furthermore, this study also demonstrated an association between ischemic CRVO and higher concentrations of homocysteine and cysteine.

Topics: Aged; Case-Control Studies; Creatinine; Cysteine; Dipeptides; Electrophoresis, Capillary; Female; Glutathione; Humans; Lipids; Male; Middle Aged; Retinal Vein Occlusion; Sulfhydryl Compounds; Taurine

Increased levels in plasma homocysteine and cysteine, and more recently, decreased levels in cysteinylglycine have been indicated as a risk factor for vascular diseases. Most assays focused their attention only on homocysteine determination and when also other thiols were measured, analytical times drastically increased. By modifying our previous method for thiols detection, we set up a rapid capillary electrophoresis method for the selective quantification of plasma cysteinylglycine, cutting the analysis time of about 50%. Samples were treated with tri-n-butylphosphine as reducing agent, proteins were precipitated with trichloroacetic acid and released thiols were successively derivatized by the selective thiol laser-induced fluorescence-labeling agent 5-iodoacetamidofluorescein and separated by capillary electrophoresis. A baseline separation between peaks was obtained in about 2 min using 3 mmol/L sodium phosphate/2.5 mmol/L boric acid as electrolyte solution with 75 mmol/L N-methyl-D-glucamine at pH 11.25 in a 47 cm long capillary with a cartridge temperature of 45 degrees C. The method application was checked by measuring plasma Cys-Gly levels in a group of patients affected by retinal vein occlusion (RVO), an important cause of visual loss in the elderly. The low levels of Cys-Gly found in the RVO patients suggest that these small thiols may have importance in the disease development.

Topics: Chromatography, High Pressure Liquid; Dipeptides; Electrophoresis, Capillary; Female; Humans; Male; Middle Aged; Retinal Vein Occlusion; Time Factors