Effects of dexamethasone on 15-lipoxygenase expression in lungs of asthmatic rats / 中国当代儿科杂志

<p><b>OBJECTIVE</b>15-lipoxygenase (15-LO) is a prooxidant enzyme which is expressed in asthmatic lungs leading to formation of pro- and anti-inflammatory mediators. Gene expression profiling studies show the association between 15-LO and allergic asthma. This study was designed to observe the expression of 15-LO in lungs of asthmatic rats and examine the effects of dexamethasone on 15-lipoxygenase expression.</p><p><b>METHODS</b>Twenty-seven male Sprague-Dawley (SD) rats were randomly divided into three groups: control, asthma and dexamethasone (DXM) intervention. An asthma model was prepared by sensitization and challenging with ovalbumin. The production of 15-LO in lung tissue homogenates was measured using ELISA.The expression of 15-LO mRNA in lungs was determined by reverse transcription-polymerase chain reaction (RT-PCR).</p><p><b>RESULTS</b>The levels of 15-LO mRNA and protein in the asthma group (0.51 ± 0.14 and 2080 ± 73 μg/mL, respectively) were lower than those in the control group (0.76 ± 0.15 and 2472 ± 106 μg/mL, respectively; P<0.01). DXM intervention increased significantly the levels of 15-LO mRNA and protein (1.02 ± 0.34 and 2562 ± 218 μg/mL) compared with the asthma group (P<0.01).</p><p><b>CONCLUSIONS</b>The production of 15-LO in lung tissues is reduced in asthmatic rats. DXM can increase the expression of 15-LO in lung tissues and thus might provide anti-inflammatory effects in asthmatic rats.</p>

Changes in urotensin-II expression in airway remodelling in asthmatic rats / 中国当代儿科杂志

<p><b>OBJECTIVE</b>To study the role of urotension-II in serum and bronchoalveolar lavage fluid (BALF) in the process of airway remodelling in asthmatic rats.</p><p><b>METHODS</b>Thirty-two male Sprague-Dawley (SD) rats were randomly divided into normal control and 2-week, 4-week and 8-week asthmatic groups (OVA inhalation of 2, 4 and 8 weeks respectively). Rats were sensitized and challenged by OVA to establish a model of asthma. The bronchial wall thickness and the airway smooth muscle thickness were measured by image analysis system. The urotension-II contents in serum and BALF were determined using ELISA.</p><p><b>RESULTS</b>The bronchial wall thickness and the airway smooth muscle thickness in the three asthmatic groups significantly increased compared with those in the normal control group (P<0.01). The urotension-II contents in serum and BALF in the three asthmatic groups also increased significantly compared with those in the normal control group (P<0.01). The urotension-II contents in serum and BALF in the 8-week asthmatic group were the highest, followed by the 4-week and the 2-week asthmatic groups (P<0.01). BALF urotension-II contents were positively correlated with the bronchial wall thickness and the airway smooth muscle thickness as well as serum U-II contents in the four groups.</p><p><b>CONCLUSIONS</b>The urotension-II contents in serum and BALF in the process of airway remodeling increase in asthmatic rats. The changes in serum and BALF urotension-II contents may be associated with airway remodeling in asthmatic rats.</p>