Purification, characterization and in vivo studies of salmon heparin.

Heparin was purified from gills and intestines from farmed Atlantic salmon (Salmo salar). Heparin activity was determined after size exclusion chromatography in the molecular weight range from above 8,000 to near 1,500. A specific activity of 110.1 antifactor Xa units/mg was measured in the less than 3,500 molecular weight fraction while 136.8 antifactor Xa units/mg was detected in a 8,000-3,500 molecular weight fraction. The presence of high affinity salmon heparin was demonstrated by using chromatography on antithrombin-Sepharose. Heparin with molecular weights lower than 3,500 was found both in high and low affinity fractions. NMR-analysis detected N- and O-sulfated oligosaccharides essential for heparin activity. The amount of salmon heparin with molecular weight lower than 8,000 varied from 12% to almost 100%. The factors determining this variation is not known, but appears to reside in the fish at the time of slaughter. The in vivo effect of salmon heparin was tested in rabbits using dalteparin as control. Salmon heparin activity was recovered in plasma samples expressed as antifactor Xa activity after intravenous administration. Based on a small number of samples and animals, the results indicate that in vivo half-life time of salmon heparin was higher than that of dalteparin.