title: Oral heparin results in the appearance of heparin fragments in the plasma of rats.
abstract: We have previously shown that angiogenesis inhibition and tumor regression can be accomplished by combinations of heparin or heparin fragments with cortisone [Folkman, J., Langer, R., Linhardt, R. J., Haudenschild, C. & Taylor, S. (1983) Science 221, 719-725]. Oral heparin was also effective in combination with cortisone. We now show that a single oral dose of [35S]heparin or [3H]heparin (15,000 units/kg) results in continuous release of radioactive material into the bloodstream for at least 12 hr. This is associated with the presence of anti-factor Xa activity at a level of approximately equal to 0.1 unit/ml. The radioactive material is identified as oligo-, di-, and monosaccharides by its behavior in chromatographic systems, its possession of anti-factor Xa activity, and the effect of treatment with bacterial heparinase. The heparin fragments are extensively metabolized to fragments without anti-factor Xa activity that are readily subject to urinary excretion.
authors.forename: A K
authors.initials: AK
authors.lastname: Larsen
authors.forename: D P
authors.initials: DP
authors.lastname: Lund
authors.forename: R
authors.initials: R
authors.lastname: Langer
authors.forename: J
authors.initials: J
authors.lastname: Folkman
mesh_terms: D000284:Administration, Oral; D000818:Animals; D004187:Disaccharides / Q000097:blood; D005170:Factor X / Q000037:antagonists & inhibitors; D015951:Factor Xa; D006493:Heparin / Q000008:administration & dosage / Q000097:blood / Q000378:metabolism*; D008297:Male; D009005:Monosaccharides / Q000097:blood; D009844:Oligosaccharides / Q000097:blood; D051381:Rats; D011919:Rats, Inbred Strains; D013462:Sulfur Radioisotopes; D013927:Thrombosis / Q000517:prevention & control; D014316:Tritium
chemical_list: D004187:Disaccharides; D009005:Monosaccharides; D009844:Oligosaccharides; D013462:Sulfur Radioisotopes; D014316:Tritium; D005170:Factor X; D006493:Heparin; D015951:Factor Xa