A dynamic test to investigate potential tissue plasminogen activator activity. Comparison of deamino-8-D-argininevasopressin with venous occlusion in normal subjects and patients.

Fibrinolysis dependent on the release of tissue plasminogen activator (t-PA) can only be explored after stimulation eliciting the release of t-PA from endothelial cells. The choice of the stimulus and test assay is of utmost importance in discriminating patients at risk for persistent thrombosis and in identifying acquired or genetic abnormalities of t-PA synthesis or release from endothelial cells in pathologic conditions. The present study was designed to compare the efficacy and reproducibility of the fibrinolytic response to desmopressin acetate (deamino-8-D-argininevasopressin) (DDAVP) by use of various routes of administration with the response to the venous occlusion test. Nine healthy male volunteers were randomly administered intravenous desmopressin acetate, intranasal drops and intranasal spray. The results from tests of euglobulin lysis time, t-PA activity, t-PA antigen levels, and t-PA fast-acting inhibitor (plasminogen activator inhibitor [PAI]) level were compared with those obtained after venous occlusion. The only test that elicited the release of free t-PA activity in the circulation in all volunteers was the intravenous administration of 0.4 microgram/kg desmopressin acetate, and the most reliable test assay was t-PA activity measured in the euglobulin fraction of plasma. Intravenous desmopressin acetate induced the release of large amounts of t-PA in most cases and caused a significant fall in PAI. Other routes of administration of desmopressin acetate, along with venous occlusion, identified many nonresponders who proved to be false negative. The relevance of these data was demonstrated in a study in nine patients with thromboembolic phenomenon or related disorders.(ABSTRACT TRUNCATED AT 250 WORDS)