A novel angiogenic inhibitor derived from Japanese shark cartilage (I). Extraction and estimation of inhibitory activities toward tumor and embryonic angiogenesis.

Guanidine extraction and crude fractionation of Japanese shark cartilage by ultrafiltration on a molecular weight basis were conducted and the antiangiogenic activities were assayed as to the inhibitions of tumor and embryonic angiogenesis. Significant inhibition of angiogenesis was found, and there was a linear relationship between the results of the two assays. The inhibitory activities were concentrated in the fraction in the molecular weight range of 103 to 104, and were resistant to heat treatment.