Different types of plasminogen activator activity in human brain tumours: relation with peritumoral oedema?

In 20 tissue samples from human brain tumours the concentrations were measured of (1) total plasminogen activator activity, (2) tissue-type plasminogen activator (t-PA) activity, (3) urokinase-type plasminogen activator (u-PA) activity, and (4) t-PA antigen. Most tumours contained a considerable amount of t-PA, but a high interindividual and in a few cases even an intra-individual variability was observed. A weak but significant negative correlation was found between t-PA concentration and the oedema/tumour ratio, as calculated from the preoperative computerized tomography (CT) brain scanning. No correlation was found with u-PA activity. It is concluded that t-PA and u-PA are probably not important factors in the production of peritumoral cerebral oedema, but a correlation between locally different amounts of t-PA or u-PA and the locally different extent of surrounding oedema has not yet been excluded.