title: Effect of gamma radiation on the molecular weight and the anticoagulant activity of heparin.
abstract: 4 g% aqueous solutions of heparin were irradiated with the gamma radiation doses of 4.6 x 10(5) or 9.2 x 10(5) rads. The irradiated and also the non-irradiated heparin samples were fractionated using a Sephadex G-200 column. With radiation, the peak of the molecular weight distribution curves shifted toward the lower molecular weight. Also, the number average molecular weight decreased by 8.2 and 11.5% with the doses of 4.6 x 10(5) and 9.2 x 10(5) rads, respectively. The anticoagulant activity depended on the molecular weight of the heparin fractions. For the heparin fractions with molecular weights below 7,900, the anticoagulant activity decreased with radiation. Thus, for a heparin fraction with a molecular weight of 6,200, the anticoagulant activity decreased from 211 to 198 IU/mg after 4 h of irradiation.
mesh_terms: D001777:Blood Coagulation / Q000187:drug effects*; D005720:Gamma Rays; D006493:Heparin / Q000494:pharmacology / Q000528:radiation effects*; D006801:Humans; D066298:In Vitro Techniques; D008970:Molecular Weight; D013997:Time Factors
chemical_list: D006493:Heparin