Abstract
The in vitro functional properties of recombinant tissue plasminogen activator (rt-PA), its biodistribution in mice, and its pharmacokinetics and clot localization properties in dogs have been investigated after labeling rt-PA with 111In. The rt-PA was coupled with the bicyclic anhydride of DTPA using standard methodology. Amidolytic and fibrinolytic assays showed retention of protein activity when rt-PA was conjugated with an average of one DTPA group or less per molecule. Size exclusion HPLC showed each preparation to be radiochemically pure with 111In bound exclusively to the attached DTPA groups. Biodistribution in mice showed major accumulation of activity in the liver and kidneys. After administration of 0.5–1.0 mg of the labeled protein to dogs, blood activity decreased with a half time of approximately 5 min in agreement with previous reports of rapid blood clearance. Largely because of decreased blood levels, clot: blood ratios of labeled protein increased rapidly, in one study reaching 6.3 after 31 min, and satisfactory images of fibrin thrombi were obtained. The rt-PA may be labeled with 111In without destroying the ability of the protein to localize in clot and images of forming clot can be obtained with this agent within 1 h after administration.
Similar content being viewed by others
References
Bischoff KB, Dedrick RL, Zaharko DS (1971) Methotrexate pharmacokinetics. J Pharm Sci 60:1128–1133
Childs RL, Hnatowich DJ (1985) Optimum conditions for labeling of DTPA-coupled antibodies with technetium-99m. J Nucl Med 26:293–299
CRC Handbook of Laboratory Animal Science. CRC Press, Boca Raton, FL 1978
deBoer AC, Paulusma-de Waal JH, Cox PH (1985) 99mTc-labeled plasminogen activator for the diagnosis of deep vein thrombosis. Thromb Haemost 54:159 (abstr)
Friberger P (1983) Synthetic peptide substrate assays in coagulation and fibrinolysis and their application on automates. Thromb Hemost 9:281–300
Fuchs HE, Berger H, Pizzo SV (1985) Catabolism of human tissue plasminogen reactor in mice. Blood 65:539–544
Gallus AS, Hirsh J, Hull R (1976) Diagnosis of veous thromboembolism. Semin Thromb Hemost 2:203–231
Gibaldi M, Perrier D (1982) Pharmacokinetics. 2nd Ed Marcell Dekker, New York
Hnatowich DJ (1986) Labeled proteins in nuclear medicine-current status. In: Billinghurst MW (ed) Proceedings, Fourth International Symposium on Radiopharmaceutical Radiopharmacology. Pergamon Press, Oxford New York, pp 257–270
Hnatowich DJ, Childs RL, Lanteigne D (1983a) The preparation of DTPA-coupled antibodies radiolabeled with metallic radionuclides: an improved method. J Immunol Methods 65:147–157
Hnatowich DJ, Layne WW, Childs RL (1983b) Radioactive labeling of antibody: a simple and efficient method. Science 220:613–615
Hnatowich DJ, Griffin TW, Kosciuczyk M (1985) Fragment E1 labeled with I-123 in the detection of venous thrombosis. Radiology 156:509–514
Knight LC, Primeau JL, Siegel BA (1978) Comparison of In-111-labeled platelets and fibrinogen for the detection of deep vein thrombosis. J Nucl Med 19:891–894
Korniger C, Stassen JM, Collen D (1981) Turnover of human extrinsic (tissue-type) plasminogen activator in rabbits. Thromb Haemost 46:658–661
Krohn KA, Knight LC (1977) Radiopharmaceuticals for thrombus detection: Selection, preparation, and critical evaluation. Semin Nucl Med 7:219–228
Kruithof EKO, Tran-thang C, Ransijn A (1984) Demonstration of a fast acting inhibitor of plasminogen activators in human plasma. Blood 64:907–913
Layne WW, Hnatowich DJ, Doherty PW (1982) Evaluation of the viability of 111In-DTPA-coupled fibrinogen. J Nucl Med 23:627–630
Lipton MH, Doherty PW, Goodwin DA (1980) Evaluation of catheter thrombogenicity in vivo with indium-labeled platelets. Radiology 135:191–194
Matsuo O (1982) Turnover of tissue plasminogen activator in man. Thromb Haemost 48:242
Matsueda GR (1985) In vivo diagnosis of thrombosis: Antifibrin monoclonal antibodies as potential agents for detection of thrombi. Thromb Haemost 54:222
Mattsson CN, Nilsson S, Haggroth L (1983) Human extrinsic plasminogen activator. Fibrinolytic properties and neutralization in vivo. Thromb Res 30:91–100
Nilsson T, Wallen P, Mellbring T (1984) In vivo metabolism of human tissue-type plasminogen activator. Scand J Haematol 33:49–53
Qureshi GD, Fratkin MJ, Robert PS (1977) Advances in the diagnosis of venous thrombosis. Prog Clin Pathol 7:317–336
Rosebrough SF, Kidryk B, Grossman ZD (1985) Radioimmunoimaging of venous thrombi using I-131 monoclonal antibody. Radiology 156:515–517
Sedman AJ, Wagner JG (1977) Auto Manual Publication Distribution Service. Ann Arbor, Michigan, pp 1–68
Sostman HD, Neumann R, Zoghbi SS (1982) Experimental studies with 111Indium-labeled platelets in pulmonary embolism. Invest Radiol 17:367–374
Sullivan DC, Silva JS, Cox CE (1982) Localization of I-131 labeled goat and primate anti-carcinoembryonic antigen antibodies in cancer. Invest Radiol 17:350–355
Author information
Authors and Affiliations
Rights and permissions
About this article
Cite this article
Hnatowich, D.J., Virzi, F., Doherty, P.W. et al. Characterization of indium-111 labeled recombinant tissue plasminogen activator for the imaging of thrombi. Eur J Nucl Med 13, 467–473 (1987). https://doi.org/10.1007/BF00281862
Received:
Accepted:
Issue Date:
DOI: https://doi.org/10.1007/BF00281862