The effect of enoxaparin on bleomycin-induced lung injury in mice

We have evaluated the effect of enoxaparin, a potent antithrombotic drag, o n bleomycin (Bleo)-induced pulmonary inflammation in mice. Pulmonary injury was induced by a single intratracheal (IT) instillation of Bleo. Four grou ps of female C57BL/6 mice, each received one of four treatments: (1) IT Ble o and daily intraperitoneal (IP) injections of enoxaparin (EN) starting one day before IT instillation of Bleo (Bleo-EN); (2) IT Bleo and IP injection s of saline (Bleo-Sal); (3) IT saline and IP enoxaparin (Sal-EN); (4) IT sa line and IP saline (Sal-Sal). Animals were sacrificed 14 days after IT trea tment. Lung injury was evaluated by analysis of bronchoalveolar lavage flui d and histologically by an overall semiquantitative index of lung injury an d a quantitative image analysis assessing alveolar mall area fraction and f ibrosis fraction. Treatment of nice with enoxaparin did not ameliorate Bleo -induced lung injury. Our study does not establish a critical role of proco agulant activity in the evolution of Bleo-induced lung injury and does not support the use of antithrombotic therapy for the prevention of pulmonary f ibrosis.