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Changes in the Fibrinolysin System During Experimental Pulmonary Hyaline Membrane Formation in Guinea Pigs.

1967; SAGE Publishing; Volume: 125; Issue: 1 Linguagem: Inglês

10.3181/00379727-125-32027

1535-3702

C. M. Ambrus, J. L. Ambrus, Kenneth R. Niswander, David H. Weintraub, J. W. Pickren,

Autopsy Techniques and Outcomes

Pulmonary hyaline membranes (HM) described in respiratory distress syndrome due to hyaline membrane disease of infants (HMD), were shown to consist primarily of fibrin (1,2). Several investigators reported deficiencies in the fibrinolysin system of infants suffering from this disease (3-7). We have proposed earlier that plasminogen develops rather late in ontogeny thus leaving premature infants without defense against pulmonary fibrin deposition which may occur from pulmonary exudates developing in relation to birth trauma (8,9). A pathologic entity similar to HMD can be induced in guinea pigs by prolonged exposure to high concentrations of oxygen and aerosolized human amniotic fluid(10,11). The purpose of this study was to investigate possible changes which may occur in the fibrinolysin system during the development of experimental HMD. Materials and methods. English smooth hair male guinea pigs of 250-350 g body weight from our own colony were used. The animals were kept in air conditioned quarters and allowed Purina guinea pig pellets, green salad leaves and water ad lib. Hyaline membranes (HM-s) were produced by the following method. Exposure to 95% oxygen was undertaken in specially constructed plastic cages, through which gas flow was continuously maintained at a rate of 5 lit/min. Oxygen concentration in the chamber was periodically checked using a Beckman Model D2 oxygen analyzer. Human amniotic fluid was nebulized into the chamber from a 24850S N.C.G. Nebulizer at a rate of 10cc/ hour using oxygen as propellant. All experiments were performed at atmospheric pressure. Human amniotic fluid was immediately frozen after collection and stored at −70°C. Thromboplastic potency was determined before use and only batches with significant activity employed. Commercially available bovine amniotic fluid showed little thromboplastic activity.