Characteristics of Tissue Plasminogen Activator from Paranasal Mucous Membrane in Chronic Sinusitis

Abstract

Tissue extract of paranasal mucous membrane from patients with chronic sinusitis was found to show a large lysis area on plasminogen-rich fibrin plates, but not on plasminogen-free fibrin plates. This indicates the existence of tissue plasminogen activator in the tissue extract. Further studies by the gel filtration technique showed that two plasminogen activators of different molecular weights were present in the tissue extract. The existence of tissue plasminogen activator with a low molecular weight has not previously been reported. This activator is labile at neutral pH at 37°C, but stable on fibrin under the above conditions. The molecular weight of this compound is lower than that of cytochrome c. It may be a compound which is proteolytically modified by proteases, ie, trypsin-like enzymes, existing in the paranasal mucous membrane tissue of patients with chronic sinusitis.