[Studies on fibrinolysis and ascites accumulation associated with peritonitis carcinomatosa--inducer of plasminogen activator (IPA) in malignant ascites tumor].

This study was undertaken to investigate the mechanism for hyperfibrinolysis in the ascites associated with peritonitis carcinomatosa. Various combinations of mouse MM2 ascites tumor (MAT) and mouse peritoneum (Mpr) and plasminogen (Plg) were incubated in medium 199 and the fibrinolytic activity of each preparation was assayed. 1) Among the preparations, the preparation of MAT plus Mpr plus Plg showed particularly high fibrinolytic activity. This suggests that plasminogen activator (PA) production is initiated by MAT together with Mpr. 2) Equal volumes of the ultrafiltrate and the concentrate of supernatant from MAT were each separately treated with a Mpr plus Plg preparation and incubated. The fibrinolytic activity of the ultrafiltrate was 10 times as great as that of the concentrate. 3) The ultrafiltrate of MAT was extracted in turn with petroleum ether, ether and hexane. The fibrinolytic activity of the petroleum ether and hexane extracts was higher than that of the ether extracts. These results suggest that MAT has a low polarity, low molecular weight, and lipid like substance (inducer of PA,IPA), which stimulates the Mpr to release PA.