LYSIS OF SURFACE-LOCALIZED FIBRIN CLOTS BY ADSORBED PLASMINOGEN IN THE PRESENCE OF TISSUE-PLASMINOGEN ACTIVATOR

The ability of plasminogen adsorbed from buffer onto sulphonated silic a glass or lysine-derivatized silica glass to lyse fibrin I clots has been investigated. Clots were formed around the test surface by adding reptilase to fibrinogen solutions in which the surfaces were immersed . Tissue plasminogen activator (t-PA) was then added and the extent of clot lysis was determined by measuring the levels of the specific pla smin cleavage product of fibrinogen, B beta 1-42 peptide. The data ind icate that in the presence of t-PA, B beta 1-42 generation per mole of bound plasminogen on the lysinized material is approximately two-fold higher than on the sulphonated material. It is concluded that a prefo rmed clot may be lysed by adsorbed plasminogen in the presence of t-PA , and that clot lysis is significantly enhanced when the plasminogen i s adsorbed via its lysine binding sites.