Enhancing effect of polyamines on yield of film sarcoma.

The salts of the natural polyamines, protamine sulphate, clupeine sulphate, spermidine phosphate, putrescine dihydrochloride and spermine diphosphate, and of the synthetic poly-L-lysine hydrobromide (mol. wt 85 k) and poly-L-arginine hydrochloride (mol. wt 50 k) were tested for their effect on film sarcoma by application in gel to nitrocellulose filters that were implanted in groups of 20-45 BALB/c mice. Five experiments were carried out using filters of decreasing pore size and increasing carcinogenicity. Control groups had filters treated with saline. The tumours that arose were fibrosarcomas, some with vascular elements. Tumour yield was expressed as the number of mouse-weeks of exposure within each group divided by the number of tumours arising. The yield was up to three times higher in the test groups, spermidine and poly-L-arginine being weakest and not reaching significance. The substances may act by producing a basic pH in the environment, by an effect on nucleic acid, by facilitating a virus or by stimulating production of a natural mitogen.