Effect of blood passage through the pulmonary circulation on fibrinolytic parameters

Abstract

The lung vasculature bed has a unique fibrinolytic potential, which has not yet been completely elucidated. We investigated the effect of blood passage through the pulmonary circulation on the values of fibrinolytic parameters in plasma. Forty-seven patients (16 women, 31 men, mean age 54 years, range 21–67 years) who had undergone elective cardiac catheterization were included in the study. The blood samples were taken simultaneously from the right atrium and the left ventricle. The following fibrinolytic parameters were measured: tissue-type plasminogen (t-PA) antigen and activity, plasminogen activator inhibitor-1 (PAI-1) antigen and activity, and euglobulin clot lysis time (ECLT). No difference was found between the samples obtained from the right atrium and the left ventricle with respect to t-PA antigen: 8.1 (6.7–11.3) vs 8.4 (5.9–11.0) ng/ml; t-PA activity: 92 (5–680) vs 62 (32–696) IU/ml; PAI-1 antigen: 8.4 (5.5–14.3) vs 8.7 (6.2–13.1) ng/ml; and ECLT: 5.5 (4.1–9.1) vs 5.6 (4.1–8.5) 1 000/min. In contrast, PAI activity decreased significantly: 7.9 (5.8–10.3) vs 7.4 (6.0–10.4) IU/ml, P ≪ 0.01. Patients with and without pulmonary hypertension did not differ in any of measured parameters, either in the right atrium or in the left ventricle. These results show that under basal conditions fibrinolytic activity which is not attributed to t-PA is elevated in lung vasculature. Further, basal fibrinolytic activity in the lungs is not influenced by pulmonary hypertension.