The Anticoagulant Activity and Toxicity of Laminarin Sulphate K

Abstract Four samples of sulphated laminarin, with differing degrees of sulphation, and two samples of fucoidin were examined for anticoagulant activity. Laminarin sulphate K, with 1·83 sulphate groups per glucose unit, showed anticoagulant activity about a third as potent as heparin. It did not cause agglutination of rabbit platelets either in vivo or in vitro, but it proved fatal to rabbits when given intravenously twice daily for periods of seven to twelve days, at a dose approximately three times the clinical dose. It was extremely toxic to guinea pigs in single small intravenous doses and produced the “anaphylactoid” phenomenon associated with some other toxic synthetic anticoagulants. Laminarin sulphate K was too toxic to justify clinical trials.