Plasminogen activator inhibitor-1 rises after hemorrhage in the rat. Yamashita, Masatomo, Daniel N. Darlington, Edwin J. Weeks, Richard O. Jones, and Donald S. Gann. Departments of Surgery and Physiology, University of Maryland School of Medicine, Baltimore, Maryland 21201
APStracts 2:0023E, 1995.
Large hemorrhage leads to hypercoagulability, a phenomenon that has never been well explained. Because an elevation of plasminogen activator inhibitor-1 (PAI-1) increases procoagulant activity, we have determined if plasma PAI activity and tissue PAI-1 mRNA are elevated after hemorrhage. Sprague-Dawley rats were bled (20 ml/kg or 15 ml/kg) four days after cannulation. Plasma PAI activity was determined by the capacity of plasma to inhibit tissue-type plasminogen activator activity. Changes of PAI-1 mRNA in various tissues were detected by high-performance liquid chromatography after reverse transcription and polymerase chain reaction. Twenty ml/kg hemorrhage significantly elevated plasma PAI activity at 0.5, 1, 2, 4, 6, and 8 h after hemorrhage, and PAI-1 mRNA in liver at 1, 2, 4, and 6 h after hemorrhage. PAI-1 message was also significantly elevated in lung, heart, and kidney at 4 h after hemorrhage. The increases of PAI-1 mRNA after 20 ml/kg hemorrhage were significantly greater than those after 15 ml/kg hemorrhage. These findings indicate that large hemorrhage can induce the increases in PAI activity and PAI-1 message and suggest that induction of PAI-1 may be involved in the thrombogenic responses observed after large hemorrhage.

Received 21 September 1994; accepted in final form 6 February
1995.
APS Manuscript Number E387-4.
Article publication pending Am. J. Physiol. (Endocrinol. Metab.).
ISSN 1080-4757 Copyright 1995 The American Physiological Society.
Published in APStracts on 25 February 1995.