Arginase activity and magnesium levels in blood of children with diabetes mellitus.
Under physiological conditions insulin controls the metabolism of carbohydrates, lipids and proteins. Diabetes mellitus is a metabolic disease characterized by a disturbance in the intermediary metabolism of glucose and glucose-induced insulin release. Arginase (L-arginine amidinohydrolase, EC 3.5.3.1) modulates nitric oxide synthase activity by regulating intracellular L-arginine availability. In diabetes mellitus, a decrease in nitric oxide bioavailability is a central mechanism for endothelial dysfunction. The aim of our study was to assess arginase activity in the blood of children with diabetes mellitus. Blood arginase activity, serum glucose (14.155 +/- 4.197 mmol/L; p < .001) and blood HbA1c (11.222 +/- 3.186 %; p < .001), were significantly higher in diabetic children than in healthy controls, whereas the magnesium (Mg2+) level, a cofactor of many enzymes, was significantly lower (0.681 +/- 0.104 micromol; p < .001). In diabetic children, arginase activity, hyperglycemia (r = 0.143), and the HbA1, level (r = 0.381) showed a positive correlation between but a negative correlation between Mg2+ and arginase activity (r= -0.206). The higher arginase activity and the lower Mg2+' levels in diabetic children could be a consequence of reduced insulin action and increased protein catabolic processes in these pathophysiological conditions. The inverse directions of arginase activity and serum Mg2+ levels are in agreement with this concept.
Bjelakovic
G
G
Institute of Biochemistry, Faculty of Medicine, University of Nis, Nis, Serbia. bjelakovic@junis.ni.ac.rs
Sokolovic
D
D
Ljiljana
S
S
Kocic
G
G
Jevtovic
T
T
Stojanovic
I
I
Ilic
M
M
Bjelakovic
L j
Lj
Zivic
S
S
Pavlovic
D
D
Nikolić
J
J
Basic
J
J
D000293:Adolescent; D001119:Arginase / Q000097:blood*; D002648:Child; D002675:Child, Preschool; D003920:Diabetes Mellitus / Q000378:metabolism*; D042783:Endothelial Cells / Q000502:physiology; D005260:Female; D006442:Glycated Hemoglobin / Q000032:analysis; D006801:Humans; D008274:Magnesium / Q000097:blood*; D008297:Male; D009569:Nitric Oxide / Q000502:physiology
D001119:Arginase; D006442:Glycated Hemoglobin; D008274:Magnesium; D009569:Nitric Oxide; C517652:hemoglobin A1c protein, human