A study on the increase of hyaluronic acid induced by smoke inhalation in rats

Objective To assess the relationship between pulmonary injury and the increase of hyaluronic acid (HA) induced by smoke inhalation in rats. Methods 40 rats were divided randomly into 5 groups: control group and experimental groups of different length of time elapsed after smoke inhalation. HA in sera, bronchoalveolar lavage fluid (BALF) and lung tissue,as well as inflammatory cells and protein in BALF, were determined. Results After smoke inhalation HA was increased in sera and lung tissue, with the peak values found at 12 h [(470.4±97.5) μg/L vs. (186.4±31.5) μg/L,(697.5±115 1) μg/L vs. (202.6±37.4) μg/L respectively],but the HA increase in BALF of different groups was insignificant. Analysis of BALF showed the highest protein content at 6 h, and the highest cell count at 12 h, with neutral granulocytes as the main component.Conclusion The inflammatory cells in the bronchi after smoke inhalation are mainly newtrophils.The content of HA in lung tissue is higher than in sera. Increased HA might be a finding indicating the lung injury induced by smoke inhalation.