▁blood ▁vessels , ▁such ▁that , ▁after ▁several ▁days ▁( when ▁the ▁ble eding ▁has ▁stopped ), ▁the ▁cl ot ▁is ▁broken ▁down . ▁This ▁occurs ▁because ▁pl as min ogen ▁became ▁entra pped ▁within ▁the ▁cl ot ▁when ▁it ▁formed ; ▁as ▁it ▁is ▁slowly ▁activ ated , ▁it ▁breaks ▁down ▁the ▁f ibr in ▁mesh . ▁t - PA ▁and ▁u ro kin ase ▁are ▁themselves ▁in hib ited ▁by ▁pl as min ogen ▁activ ator ▁in hib itor - 1 ▁and ▁pl as min ogen ▁activ ator ▁in hib itor - 2 ▁( PA I - 1 ▁and ▁PA I - 2 ). ▁In ▁contrast , ▁pl as min ▁further ▁stim ul ates ▁pl as min ▁generation ▁by ▁producing ▁more ▁active ▁forms ▁of ▁both ▁t issue ▁pl as min ogen ▁activ ator ▁( t PA ) ▁and ▁u ro kin ase . ▁ ▁Al pha ▁ 2 - anti pl as min ▁and ▁alpha ▁ 2 - mac rog lob ul in ▁in activ ate ▁pl as min . ▁Pl as min ▁activity ▁is ▁also ▁reduced ▁by ▁th rom bin - activ atable ▁f ibr in ol ysis ▁in hib itor ▁( TA FI ), ▁which ▁mod ifies ▁f ibr in ▁to ▁make ▁it ▁more ▁resist ant ▁to ▁the ▁t PA - medi ated ▁pl as min ogen . ▁ ▁Me asure ment ▁When ▁pl as min ▁breaks ▁down ▁f ibr in , ▁a ▁number ▁of ▁sol ub le ▁parts ▁are ▁produced . ▁These ▁are ▁called ▁f ibr in ▁de