[Effect of hyaluronidase on porcine pancreatic elastase-induced lung injury]

The present study was conducted to investigate the effects of hyaluronidase on elastase-induced lung injury in rats. Male Wistar rats were divided into 4 groups: 1) Control group, single tracheal instillation of 0.3 ml saline; 2) PPE group, single tracheal instillation of 120 micrograms porcine pancreatic elastase (PPE); 3) HD group, intravenous injection of 240 mg/kg hyaluronidase (HD); and 4) HE + PPE group, intravenous injection of HD before single tracheal instillation of PPE. Cellular component and protein concentration in bronchoalveolar lavage fluid (BALF), myeloperoxidase (MPO) activity and hyaluronan content in lungs were examined 24 hours after treatment. After 8 weeks of treatment, hyaluronan content in the lungs and physiological parameters such as total lung capacity (TLC), functional residual capacity (FRC) and static compliance (Cst) were examined. The number of BALF nucleated cells in the HD + PPE group 6 h after treatment, and lung MPO activity in the HD group after 1 h and 3 h. were both higher than the corresponding measurements in the PPE group. After 6 h of treatment, the number of BALF nucleated cells in the HD + PPE group was significantly higher than in the HD group. The BALF albumin concentrations in the HD + PPE and HD groups were also significantly higher than in the control group. After 8 weeks of treatment, the measurements of TLC and Cst indicated greater emphysematous changes in the HD + PPE group. These results suggest that decreased interstitial HA accelerates acute inflammation and emphysematous changes in elastase-induced lung injury.