Studies On The Neuroprotective Effects Of Uric Acid In Parkinson's Disease

PARTⅠStudy on Serum Uric Acid Concentrations of Patients with Parkinson's DiseaseObjective To analyze serum uric acid concentrations of patients with Parkinson's disease and discuss characteristic of serum uric acid in Parkinson's disease.Methods We measured and analyzed their serum uric acid and hemoglobin concentrations in 121 patients with Parkinson's disease who identified in Second-Affiliated Hospital of Suzhou University during 1999—2007 and 121 age matched healthy persons who identified in our hospital as controls.Results Patients with Parkinson's disease were found to have lower serum uric acid concentrations (260.76±90.42μmol/l) than controls (336.95±59.64μmol/l, P<0.01). There was no significant difference about serum uric acid concentrations in Patients with Parkinson's disease between men group (273.63±102.12μmol/l) and women group (247.23±74.72μmol/l, P>0.05), but there was significant difference in controls (349.63±54.31μmol/l,322.25±62.59μmol/l, P<0.01). There was no significant difference about serum uric acid concentrations in Patients with Parkinson's disease among H-YⅠⅡ(258.17±80.27μmol/l),Ⅲ(251.63±103.85μmol/l),ⅣⅤ(281.86±70.76μmol/l) three groups. There was no close correlation between serum uric acid and hemoglobin in Patients with Parkinson's disease (r=0.065,P >0.05) and controls (r=0.177, P >0.05).Conclusion Serum uric acid concentrations in Patients with Parkinson's disease decreased, lower serum uric acid was one of risk factors of Parkinson's disease. PARTⅡUric Acid Decreased Toxic Effects of Nigrostriatal System of Rats by 6-HydroxydopamineObjective To study on uric acid's decreasing toxic effects of nigrostriatal system of rats by 6-hydroxydopamine.Methods Male SD rats were divided into six groups, saline group(n=10),uric acid of 50mg/kg group(n=5),uric acid of 100mg/kg group(n=5),uric acid of 150mg/kg group(n=8), uric acid of 200mg/kg group(n=10),uric acid of 250mg/kg group(n=5).Different groups of rats were intraperitoneally injected (ip) saline or different concentration of uric acid two times daily at intervals of two hours for five days. On the 6th day, rats were made into Parkinsonian rats by unlitale lesion induced by 6-hydroxydopamine after the first time of intraperitoneally injecting (ip) saline or different concentration of uric acid and continued being treated with saline and uric acid ip twice a day for 5 days. Apomorphine-induced rotation test and locomotion test were performed to examine the disease progress in rat model in the 3rd week after injecting 6-hydroxydopamine. Amphetamine-induced rotation test and forepaw adjusting step test were done in the 4th week after injecting 6-hydroxydopamine. In the fifth week after injecting 6-hydroxydopamine, rats were killed to determine the level of dopamine and HVA in the striatum.Results Uric acid of 200mg/kg group (10.89±7.58 ) was significantly lower than saline groups (19.3±5.29,P<0.01) about amphetamine-induced rotation test scores. Uric acid of 200mg/kg group was higher significantly about score of locomotion in 2 minutes (14.02±4.22) and forepaw adjusting step test scores (9.89±3.41) than group of saline (4.13±5.99,P<0.01;4.36±3.72,P<0.01).Level of DA in the lesioned Striatum of Uric acid of 200mg/kg group (0.29±0.19ng/mg) was significantly higher than saline group (0.05±0.03ng/mg,P<0.01),50mg/kg UA group (0.08±0.67ng/mg,P<0.05), 150mg/kg UA group (0.07±0.73ng/mg,P<0.01) and 250mg/kg UA group (0.06±0.74ng/mg,P<0.01). Level of HVA in the lesioned Striatum of Uric acid of 200mg/kg group (1.22±0.52ng/mg) was significantly higher than saline group (0.24±0.13ng/mg,P<0.05) and 250mg/kg UA group (0.39±0.28ng/mg,P<0.05). Conclusion Increasing the level of uric acid probably could improve toxic effects of nigrostriatal system of rats by 6-hydroxydopamine .