Malondialdehyde level and adenosine deaminase activity in nasal polyps.

Abstract

Although there are many reports on adenosine deaminase (ADA) activities in different tissues, no information is available about the enzyme activity in nasal mucosa and polyp tissues. Whereas ADA is related to the production of free radicals by neutrophils, malondialdehyde (MDA) is an indicator of lipid peroxidation that is a general mechanism of tissue damage by free radicals. This study is aimed at determining and comparing the ADA activity and MDA level in nasal polyps and normal mucosa. Twenty-three patients with nasal polyps and a control group consisting of 14 patients with septal deviation and lower turbinate hypertrophy were included in the study. Tissue MDA level was measured by the method of Okawa with modification and tissue ADA activity by the method of Giusti. In patients with nasal polyp, mean tissue MDA level and ADA activity were 2.43 +/- 0.38 nmol/mg protein (Pr) and 0.235 +/- 0.055 U/mg Pr, respectively, which were significantly higher than those of control nasal mucosa (1.03 +/- 0.41 nmol/mg protein and 0.056 +/- 0.011 U/mg Pr, respectively) (P < 0.05). In addition, tissue MDA level was positively correlated to ADA activity in nasal polyps (r = 0.701, P < 0.001). The present study showed the presence of detectable ADA activity in nasal mucosa, and also significant increases in both tissue MDA level and ADA activity in NP tissue when compared to normal turbinate tissue. B-2b.