| Abstrakt: |
High levels of arginine and its derivatives often accompany chronic kidney disease (CKD). Arginase 2(ARG2) is the enzyme that converts arginine into ornithine and urea. The aim of the study is to know the relationship of ARG2 activity with the progression of CKD. 45 children with CKD from stages 4 and 5, in addition to 30 healthy children, free of disease, as a control group, participated in this study. The levels of ARG2 activity, symmetric dimethylarginine SDMA concentration, creatinine, urea and hemoglobin Hb concentrations were measured in the blood samples of all the participating children, and the glomerular filtration rate GFR was calculated using Schwartz equation to know the stage of renal disease, as well as it was calculated for healthy children for comparison. A ready-made kit was used to measure the activity of ARG2 by spectrophotometric method, the SDMA concentration was measured using HPLC, the urea, creatinine and Hb concentrations were measured using a routine kits by the hospital laboratory. It was noticed that there was a significant decrease in ARG2 Activity mean in patients group as compared to control group, (0.084± 0.031 vs 0.096±0.008 with Pvalue = 0.001) also there were significant decrease in means of Hb and GFR in patients group as compared to control group (9.10 ± 1.95 vs 12.18±0.98, Pvalue = 0.001) and (14.82 ± 6.86 vs 187.34±33.34, P-value = 0.001) respectively, in contrast, there were remarkable increase in SDMA, Creatinine and Urea means in patients group as compared to control group individuals with (1.16± 0.354 vs 0.39 ± 0.11, Pvalue = 0.001), (5.59 ± 2.38 vs 0.49±0.17, Pvalue = 0.001) and (27.53± 12.6 vs 3.28±0.92, Pvalue = 0.001), respectively. The data showed several negative and positive relationships, most notably a positive relationship between ARG2 activity and SDMA, accounting for 9% of the variability of ARG2 activity (r = 0.293, r2 = 0.09 & Pvalue = 0.043). SDMA showed inverse moderate relationship with Hb, accounting for 22% of the variability of Hb (r = -0.466, r2 = 0.22 & Pvalue = 0.001). SDMA also showed significant direct relationship with urea which accounting for 11% of the variability of urea (r = 0.334, r2 = 0.11 & P value = 0.020). Creatinine also showed a moderate positive relationship with urea which represent 25% of the variability of urea (r = 0.498, r2 = 0.25 & P value = 0.0001) and two negative relationships with Hb and GFR, accounting for 20%-55% of the variability of creatinine (r = -0.444, r2 = 0.20 & P value = 0.002) and (r= -0.739, r2 = 0.55 & Pvalue = 0.0001), respectively. Urea showed two inverse moderate relationships with Hb and GFR, accounting for 18%-24% of the variability of urea (r = -0.422, r2 = 0.18 & Pvalue = 0.003) and (r= - 0.489, r2 = 0.24 & Pvalue = 0.0001), respectively. In conclusion, the activity of arginase 2 enzyme is clearly decreased in children with chronic kidney disease compared to healthy children and is significantly correlate to symmetric dimethylarginine. [ABSTRACT FROM AUTHOR] |
