Disposition of fractionated 3H-heparin in rats.

Abstract

To evaluate the disposition of fractionated 3H-heparin, high affinity fraction (fraction A) and low affinity fraction (fraction NA) to protamine were prepared from commercial 3H-heparin by affinity chromatography on protamine-Sepharose and gel filtration chromatography. Following i.v. administration of fraction A to rats, the radioactivity in plasma apparently declined one-exponentially with time to a pseudo-steady-state level, and 20.5% of dose was excreted in urine in 5 h. Following the administration of fraction NA to rats, the plasma radioactivity curve was different from that of fraction A, and 69.8% of dose was excreted in urine in 5 h. Fraction A and fraction NA evidently had the distinctly different disposition characteristics in the body. Whole-body autoradiography with fraction A showed that the liver, bone marrow, kidney cortex, salivary gland and intestine played an important role in its distribution. Gel filtration chromatography and affinity chromatography suggested that the main material of the radioactivity excreted in urine in 5 h has the same properties as that of the administered heparin fraction.