title: L-arginine catabolism is driven mainly towards nitric oxide synthesis in the erythrocytes of patients with type 2 diabetes at first clinical onset.
abstract: BACKGROUND
  We investigated the l-arginine (l-Arg)-nitric oxide (NO) metabolic pathway in the erythrocytes (RBCs) and plasma of subjects with type 2 diabetes at first clinical onset.
  
  
  METHODS
  RBCs and plasma were collected from 26 patients with type 2 diabetes at first clinical onset and 19 age-matched non-diabetes subjects as controls. l-Arg content was assayed by capillary electrophoresis. We measured arginase activity and nitrate/nitrite concentrations by spectrophotometry, and glycosylated haemoglobin (HbA1c) by standardized immunoturbidimetry.
  
  
  RESULTS
  We found that, when compared with controls, l-Arg content was similar in RBCs while decreased in the plasma of patients with type 2 diabetes. Interestingly, arginase activity was lower in RBCs and increased in plasma of patients with diabetes. NO production was higher in RBCs in patients with type 2 diabetes, while no difference was found in the plasma of our subjects.
  
  
  CONCLUSIONS
  l-Arg catabolism is driven mainly towards NO synthesis in RBCs of patients with type 2 diabetes at first clinical onset. The decreased RBC arginase activity could be considered a potential mechanism of increased RBC NO production in early diabetes. Therefore, the RBC pool would represent a potentially compensatory intravascular compartment for endothelial dysfunction in diabetes.
authors.affiliation: National Institute of Diabetes, Nutrition and Metabolic Diseases 'N.C. Paulescu', Bucharest, Romania.
authors.forename: Octavian
authors.initials: O
authors.lastname: Savu
authors.affiliation: R&D Irist Labmed SRL, Bucharest, Romania.
authors.forename: Liviu
authors.initials: L
authors.lastname: Iosif
authors.affiliation: National Institute of Diabetes, Nutrition and Metabolic Diseases 'N.C. Paulescu', Bucharest, Romania.
authors.forename: Ovidiu Marius
authors.initials: OM
authors.lastname: Bradescu
authors.affiliation: National Institute of Diabetes, Nutrition and Metabolic Diseases 'N.C. Paulescu', Bucharest, Romania.
authors.forename: Cristian
authors.initials: C
authors.lastname: Serafinceanu
authors.affiliation: Physiology Department, University of Medicine and Pharmacy 'Carol Davila', Bucharest, Romania.
authors.forename: Raluca
authors.initials: R
authors.lastname: Papacocea
authors.affiliation: R&D Irist Labmed SRL, Bucharest, Romania Biochemistry Department, University of Medicine and Pharmacy 'Carol Davila', Bucharest, Romania irina_stoian64@yahoo.com.
authors.forename: Irina
authors.initials: I
authors.lastname: Stoian
mesh_terms: D001119:Arginase / Q000097:blood*; D001120:Arginine / Q000097:blood*; D016022:Case-Control Studies; D003924:Diabetes Mellitus, Type 2 / Q000097:blood* / Q000150:complications / Q000175:diagnosis; D019075:Electrophoresis, Capillary; D004912:Erythrocytes / Q000737:chemistry / Q000378:metabolism*; D005260:Female; D006442:Glycated Hemoglobin / Q000378:metabolism; D006801:Humans; D006973:Hypertension / Q000097:blood* / Q000150:complications / Q000175:diagnosis; D008297:Male; D008875:Middle Aged; D009566:Nitrates / Q000097:blood; D009569:Nitric Oxide / Q000096:biosynthesis*; D009573:Nitrites / Q000097:blood
chemical_list: D001119:Arginase; D001120:Arginine; D006442:Glycated Hemoglobin; D009566:Nitrates; D009569:Nitric Oxide; D009573:Nitrites; C517652:hemoglobin A1c protein, human
keywords:    l-arginine; nitric oxide; type 2 diabetes