Thromb Haemostasis
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Plasminogen knock-out (PG(-/-)) mice provide an unique opportunity for the study of alternative mediators of fibrinolysis. Polymorpho-nuclear leucocytes (PMNs) contain non-plasmin fibrinolytic proteases, however the degree to which these cells contribute to fibrin(ogen) degradation in these animals is not known. Thrombi were generated in carotid arteries and jugular veins of PG(-/-) and wild type (PG(+/+)) mice following adventitial application of a 20% ferric chloride solution. ⋯ Furthermore, autoradiographic analysis of the I(125)-labeled fibrinogen degradation products showed the cleavage pattern by PG(-/-) PMNs to be distinct from that produced by PG(+/+) PMNs. These data suggest that a relatively greater role for PMNs-initiated fibrinolysis exists in the setting of plasminogen deficiency, although this prominence only becomes evident more than 24 h after the thrombotic insult. In addition, mechanisms responsible for the process in PG(-/-) mice may be distinct from those primarily responsible for the process in PMNs from PG(+/+) mice.