Airway Hyperresponsiveness and Bronchoalveolar Fluid Inflammatory Cells in Obese Asthmatic Male Rats

Abstract

Background & objectives: Epidemiological and clinical studies have shown a close relationship between asthma and obesity. The present study examined the effect of obesity on the airway response to methacholine and the number of inflammatory cells in the bronchoalveolar fluid of ovalbumin-sensitized male rats. Methods: Twenty-four male Wistar rats were divided into 4 groups: normal diet (C+ND), OVA‐sensitized with the normal diet (S+ND), high-fat diet (C+HFD) and OVA‐sensitized with high‐fat diet (S+HFD). All animals were fed for 8 weeks with standard diet or high-fat diet, and then were sensitized with ovalbumin or normal saline for another 4 weeks while receiving the designed regimens. At the end of the study, the number of inflammatory cells in bronchoalveolar fluid (BALF) and tracheal responsiveness to methacholine were examined. Results: In diet-induced obesity groups, weight and obesity indices increased (p<0.05 to p<0.001). The results also showed that tracheal responsiveness to methacholine in S+HFD group compared to S+ND group, was significantly increased (p<0.05). In addition, the number of inflammatory cells in the BAL, in the S+HFD group was higher than other groups (p<0.001). Conclusion: the results of this study suggest that the response of the airways to methacholine and the number of inflammatory cells are increased in obese-asthmatic male rats