抄録
Influence of hydrolytic product of fibrin and embryonic tissue juice on the growth of tissue (epithelial and fibroblast strain) in vitro was studied by the slide culture method.
HCl-pepsin digest of fibrin had a growth-stimulating effect on both kinds of tissue, when added to the dialysed embryonic tissue juice which has no effect when used alone. The opitimum concentration of the digest, which was obtained in such a way that 1g of fibrin was digested by HCl-pepsin during 24 or 48 hours and the ratio of the residual N to the total N was about 0.45, was one fourth of the dialysed tissue juice.
Promotion of the digestion by trypsin (the ratio of the residual N to the total about 0.74) did not further favour the effect of the pepsin digest and produced rather some toxic substance for the growth, which was manifested when the trypsin digest was added to the nutritive medium in one third. The trypsin digest of embryonic tissue pulp, which was obtained in the same way as with the fibrin and had the same ratio 0.74 of the residual N to the total N, was much more toxic for the growth of tissue in vitro.
When the decomposition of embryonic tissue pulp was completed by concentrated HCl, the ratio of the residual N to the total N being one, any growth-stimulating effect was not perceived in the product, the concentration of which lay between one twentieth to one five-hundredths, and a rather toxic effect was observed. The HCl-hydroly-te, when added in proportion between one five-hundredths to one two-thousandths of the nutritive medium, did not manifest any growth-toxic or -stimulating influence.
