[Collagenolytic activity of neoplastic and rapidly proliferating normal tissue].

By means of a biological collagenase assay the activity of this protease was examined in 12 invasive adenocarcinomas of the colon and compared to that in 10 normal thymus tissue biopsies. Collagenolytic activity at dimensions of 10(-3) units/mm diameter tissue could be revealed in all carcinomas, which significantly (p less than 0.001) surpassed the also regularly detectable activity in thymi. While 0-Phenantrolin and D-Penicillamin totally inhibited lysis of each sample, EDTA and normal human serum, remarkably inhibiting collagenase of normal thymus, only were able to reduce the lysis by cancer at 19 and 23% in the average leading to enzyme: inhibitor imbalance in malignancy. It can be suggested that collagenolysis displayed by adenocarcinomas is derived from the tumor itself, and is different from that of normal thymus--a rapidly proliferating organ--by means of enzymatic quantity and quality.