Abstract: Objective To investigate the effects of Dingchuan granules on viral load, inflammatory factors and airway resistance in lung tissue of young rats with respiratory syncytial virus(RSV) pneumonia.Methods Thirty young SD mice were randomly divided into three groups: normal group, RSV pneumonia group, and Dingchuan granules intervention group, with 10 mice in each group. Establish RSV pneumonia model using nasal drip method. Double chamber tracing method was used to detect airway resistance in mice, and hematoxylin eosin staining (HE staining) method was used to observe pathological changes in lung tissue. ELISA method was used for detecting the content of interleukin-8 (IL-8) and tumor necrosis factor (TNF-α) and interleukin-1β (IL-1β) in alveolar lavage fluid(BALF). Results（1）Viral load: Compared with the normal group, RSV pneumonia group and Dingchuan granules intervention group had higher viral load (P<0.05).Compared with the RSV pneumonia group, the viral load in the Dingchuan granules intervention group was significantly lower (P<0.05). （2） In terms of airway resistance: Compared with the normal group, both the RSV pneumonia group and the Dingchuan granules intervention group showed an increase in airway resistance (P<0.05). Compared with the RSV pneumonia group, the airway resistance of the Dingchuan granules intervention group was significantly reduced (P<0.05). （3） In terms of pathological injury and dry-to-wet ratio: Compared with the normal group, the RSV pneumonia group and the Dingchuan granules intervention group showed an increase in pathological injury score and lung wet-to-dry ratio (P<0.05). Compared with the RSV pneumonia group, the pathological injury score and lung wet-dry ratio of the Dingchuan granules intervention group were both reduced (P<0.05). （4）In terms of IL-8 ,TNF-α and IL-1β content in BALF: Compared with the normal group, the RSV pneumonia group and the Dingchuan granules intervention group had significant increase in IL-8，TNF-α and IL-1β content (P<0.05). Compared with the RSV pneumonia group, the Dingchuan granules intervention group showed significant decrease in the content of IL-8, TNF-α and IL-1β(P<0.05). Conclusion Dingchuan granules can reduce the viral load in lung tissue, reduce airway resistance, improve the degree of lung injury, and inhibit the level of inflammatory factors of RSV pneumonia in young rats.

Key words:

Respiratory syncytial virus, Dingchuan granules, Inflammatory factors in lung tissue, Airway resistance, Rat