Plasminogen did not affect lung function in surfactant-treated preterm lambs

Preterm infants with respiratory distress syndrome develop fibrin-rich hyal ine membranes within the alveoli and have depressed fibrinolytic activity, which is thought to be due to a relative deficiency of plasminogen. Local f ibrin deposition inhibits surfactant function and amplifies inflammation. W e hypothesized that plasminogen administration to surfactant-treated preter m lambs would prevent fibrin-rich hyaline membrane formation, resulting in the amelioration of lung pathology and improved lung function, We randomly treated preterm lambs (gestational age 127-129 days) with either 16 mg of l ysine-plasminogen (n = 10) or saline (n = 10), and ventilated them for 5 h, There were no significant differences in physiologic measurements of lung function (ventilation efficiency index, oxygenation index, dynamic complian ce, quasi-static pressure volume curve), measures of lung injury (alveolar wash protein content and I-125-albumin recovery) or surfactant pool size. T he degree and extent of bronchiolar erosion and hyaline membrane formation were similar in the two groups. Plasminogen administration did not improve lung function or prevent hyaline membrane formation in surfactant-treated l ambs, Copyright (C) 2000 S. Karger AG, Basel.