Uptake and distribution of tritium-labeled polysulfated glycosaminoglycan in serum, urine, and superficial digital flexor tendon of rabbits after intramuscular administration

Objective-To determine concentrations of tritiated polysulfated glycosamino glycans (H-3-PSGAG) in serum, urine, and the superficial digital flexor ten don (SDFT) of rabbits after IM administration and molecular weight of H-3-P SGAG recovered from the SDFT. Animals-Twenty-five 12-week-old New Zealand White rabbits, Procedure-Rabbits were given a single dose of H-3-PSGAG (1.1 mg/kg [70 mCi of specific activity//kg] of body weight) IM. At each of 5 sample limes (2, 24, 48, 96, and 192 hours), 5 rabbits were randomly selected and sedated, and blood and urine samples were collected. Rabbits were then euthanatized, and the SDFT were immediately harvested from the hind limbs. Scintillation spectrometry was used to detect concentration of H-3-PSGAG in fluid and ti ssue samples. Gel-filtration chromatography was used to determine molecular weight of recovered H-3-PSGAG. Results-Mean concentrations of H-3-PSGAG in SDFT, serum, and urine were gre atest 2 hours after administration. Tritiated PSGAG could be detected in al l samples collected 192 hours after administration. Gel-filtration chromato graphy confirmed that H-3-PSGAG detected in SDFT samples was high molecular weight PSGAG. Conclusions and Clinical Relevance-Results indicate that PSGAG is distribut ed to the SDFT, serum, and urine after IM administration in rabbits. Furthe r study is needed to determine whether the same is true in horses and to de termine what effect, if any, PSGAG has on inflammation of the SDFT.