[The role of glucocorticosteroid and theophylline in asthmatic inflammation of murine model and the inhibition in NO production in lung].
Keywords
Abstract
OBJECTIVE
To investigate the role of glucocorticosteroid and theophylline in treatment of asthmatic inflammation and their effects in production of nitric oxide (NO) and the expression of inducible nitric oxide synthase (iNOS).
METHODS
A murine model was set up (A group: asthma model, N group: control mice), then the number of WBC, eosinophils% (EOS), total protein level and the NO level in brochoalveolar lavage fluid (BALF) were measured after treatment with glucocorticosteroid (C1 group: dexamethason inhalation; C2 group: dexamethason peritoneal injection and C3 group: budisonide inhalation) and aminophylline(T group). The expression of iNOS was studied by histochemistry and immunohistochemistry.
RESULTS
There was a significant increase in number of WBC [(10.64 +/- 0.75) x 10(7)/L vs (3.15 +/- 0.92) x 10(7)/L, P < 0.001), EOS% (12.55% +/- 7.64% vs 0.02% +/- 0.04%, P < 0.001), total protein level (0.124 +/- 0.080 g/L vs 0.008 +/- 0.004 g/L, P < 0.001) and concentration of NO (5.00 +/- 1.87 mumol/L vs 1.30 +/- 0.67 mumol/L, P < 0.001) in BALF after antigen challenge, and the expression of iNOS was increased in airway epithelial cells and alveolar macrophages. After administration of steroids and theophylline, the number of WBC[C1: (5.05 +/- 1.14) x 10(7)/L, C2: (5.47 +/- 0.59) x 10(7)/L, C3: (6.53 +/- 0.47) x 10(7)/L, T: (3.65% +/- 1.04) x 10(7)/L, P < 0.001], EOS% (C1: 0.10% +/- 0.06%, C2: 0.10% +/- 0.08%, C3: 0.24% +/- 0.33%, T: 2.84% +/- 1.90%, P < 0.001-0.005), total protein level (C1: 0.016 +/- 0.011 g/L, C2: 0.010 +/- 0.008 g/L, C3: 0.020 +/- 0.012 g/L, T: 0.012 +/- 0.008 g/L, P < 0.001-0.05) were significantly decreased. There was a significant reduction of NO level (C1: 1.20 +/- 0.97 mumol/L, P < 0.001) and iNOS expression after treated with steroids, but no significant change after management with theophylline.
CONCLUSIONS
EOS is main inflammatory cell in asthma. NO may play an important role in aggravating asthma. Steroids and theophylline both can inhibit cell infiltration and serum protein leakage in asthma. Steroids can also inhibit the production of NO and iNOS expression. But theophylline has no significant effect in NO.
