Zur Frage des Vorkommens von sterisch auslesenden Enzymen im carcinomatösen Organismus Feststellungen zu zwei vorläufigen Mitteilungen von E. Waldschmidt-Leitz und Mitarbeitern
The authors were unable to confirm the results of Waldschmidt-Leitz and coworkers, who reported that the sera of subjects with carcinoma were able to hydrolyze over 50% of racemic peptides (d,l-leucylglycine, d,l-alanylglycine, d,l-glutaminyl- glycine, d,l-glutaminylglycine ester). The tests were carried out with the sera of 11 patients with carcinoma, of 3 rabbits with Brown-Pearce tumors, and of 4 normal human subjects, d-leucylglycine and d-leucylglycylglycine were not attacked by these sera. 1.5 cc. of peptide soln. was added to 3.5 cc. of serum and the temp. of the soln. was maintained at 40[degree] for 36-48 hrs., pH 7.70-8.00. 2 cc. of the soln. was then titrated with N/20 KOH. When a d,l-peptide was injected into rabbits, the hydrolysis of the d,l-peptide was observed only occasionally. Solns. of racemic peptides and extracts of Brown-Pearce tumors injected into rabbits promoted the growth of implanted tumors.