METHODS: Fifty adult female Wistar rats were randomly divided into two groups: One group was intratracheal-ly instilled with bleomycin ( BLM), while another group with 9 g/L NaCI solution (NS).

• 方法:50只健康雌性Wistar大鼠随机分成博莱霉素(BLM)组和生理盐水(NS)组各25只,气管内分别灌注BLM和NS。