A potential role for nitric oxide pathway in tuberculous pleural effusion.
METHODS
Tuberculous pleural effusion leads to an immune response involving mainly immune and mesothelial cells. Nitric oxide (NO) produced by these cells may have antimycobacterial effects against Mycobacterium tuberculosis.


OBJECTIVE
To investigate the possible role of NO in connection with the arginase enzyme, which controls the synthesis of NO through arginine depletion.


METHODS
Pleural fluid samples from 20 patients with tuberculous pleural effusion were used for arginase activity and NO level determination. Results were compared with those from 12 lung cancer, 12 pneumonia and 12 congestive heart failure (CHF) patients.


RESULTS
Pleural arginase activity in tuberculosis patients was found to be significantly decreased compared to lung cancer and pneumonia groups, while the NO level was higher in tuberculosis patients. All groups except the CHF group had significant correlations between NO level and white blood cell count. Arginase activity and red blood cell count correlated significantly in lung cancer and CHF groups.


CONCLUSIONS
The arginine-NO pathway seems to be involved in the pathogenesis of tuberculous pleural effusion. Decreased arginase activity may cause arginine accumulation, which may then lead to increased NO synthesis by immune and mesothelial cells, reflecting a host defence mechanism.
Elgün
S
S
Department of Biochemistry, School of Medicine, Ankara University, Sihhiye, Ankara, Turkey. elgun@medicine.ankara.edu.tr
Kaçmaz
B
B
Durak
I
I
D000368:Aged; D001119:Arginase / Q000378:metabolism; D015415:Biomarkers / Q000378:metabolism; D004906:Erythrocyte Count; D045604:Extracellular Fluid / Q000166:cytology / Q000378:metabolism; D005260:Female; D006333:Heart Failure / Q000150:complications / Q000378:metabolism / Q000473:pathology; D006801:Humans; D007958:Leukocyte Count; D008175:Lung Neoplasms / Q000150:complications / Q000378:metabolism / Q000473:pathology; D008297:Male; D008875:Middle Aged; D009569:Nitric Oxide / Q000378:metabolism*; D010996:Pleural Effusion / Q000209:etiology / Q000378:metabolism* / Q000473:pathology; D011014:Pneumonia / Q000150:complications / Q000378:metabolism / Q000473:pathology; D014397:Tuberculosis, Pulmonary / Q000150:complications / Q000378:metabolism* / Q000473:pathology
D015415:Biomarkers; D009569:Nitric Oxide; D001119:Arginase