ABSTRACT
BACKGROUND: The purpose of this study was to investigate plasma homocysteine levels and polymorphisms in genes encoding enzymes in the metabolic pathway of homocysteine in association with primary open-angle glaucoma (POAG) and pseudoexfoliation glaucoma (PXFG). METHODS: A total of 156 glaucoma patients (76 with POAG and 80 with PXFG) and 135 controls matched for age and sex were enrolled in this study. Plasma homocysteine levels were measured using a commercially available enzyme-linked immunosorbent assay kit. DNA was extracted from peripheral blood leukocytes and real-time polymerase chain reaction was performed for genotyping of the samples. Patients were genotyped using predesigned TaqMan(®) single nucleotide polymorphism genotyping assays for two exon variations (rs1801131, rs1801133) in the 5,10-methylenetetrahydrofolate reductase (MTHFR) gene and one intron variation (rs8006686) in the methylenetetrahydrofolate dehydrogenase (MTHFD1) gene. RESULTS: Homocysteine levels were slightly higher in the patient group (POAG and PXFG) compared with controls, but the difference did not reach statistical significance. The minor alleles of the MTHFR single nucleotide polymorphisms showed a protective effect for POAG and showed an increased risk for PXFG, but none of these associations reached statistical significance (P>0.05). The minor allele of MTHFD1 rs8006686 showed a trend for increased risk of both POAG and PXFG (P>0.05). No statistically significant interaction was seen between the genetic variants and homocysteine levels (P>0.05). CONCLUSION: Our results show that neither the examined single nucleotide polymorphisms from genes involved in the pathway of homocysteine metabolism nor the measured homocysteine levels were associated with POAG or PXFG in our study cohort.
ABSTRACT
Moxonidine is the newest, second-generation, centrally acting antihypertensive agent. It has selective agonist activity at imidazoline I1 receptors and less adverse effects than the other centrally acting drugs. This fact authorizes the frequent use of moxonidine in clinical practice, as monotherapy or in combination with other antihypertensive agents. Also, moxonidine has beneficial effects in obese and metabolic syndrome and in target-organs, such as heart and kidneys.
ABSTRACT
BACKGROUND: Asymmetric dimethyloarginin or dimethylarginin (ADMA) is a marker and maker of oxidative stress. It is elevated in several pathological conditions, such as hyperhomocysteinemia and endothelial dysfunction, which have also been reported in patients with exfoliation syndrome (XFS), or exfoliative glaucoma (XFG). We evaluated ADMA levels in the aqueous humor of XFS and XFG patients. METHODS: This study included 48 aqueous samples; 16 from cataract patients with XFS, 16 from cataract patients with XFG and 16 from age-matched cataract control patients. ADMA levels were determined employing a commercial ELISA kit. RESULTS: ADMA concentration was significantly greater in XFG patients (0.398 ± 0.026 µM) compared to either XFS (0.168 ± 0.028 µM; p < 0.0001) or normal cataract controls (0.245 ± 0.025 µM; p = 0.0002). In contrast, no significant difference was detected for ADMA levels in the aqueous of XFS patients as compared to normal controls (p = 0.0477). CONCLUSIONS: Aqueous humor ADMA concentration is significantly elevated in XFG patients supporting the view that oxidative stress plays a key role in XFG pathobiology. The lower level of this marker in XFS suggests that the development of XFG is a prerequisite for ADMA elevation.
