title: (111)Indium Labelling of Recombinant Activated Coagulation Factor VII: In Vitro and Preliminary In Vivo Studies in Healthy Rats.
abstract: The aim of this study is to investigate whether (111)Indium-labelled recombinant FVIIa (rFVIIa) could be a potential radiopharmaceutical for localization of bleeding sources. DTPA-conjugated rFVIIa was radiolabelled with (111)In chloride. In vitro binding efficiency of (111)In-DTPA-rFVIIa to F1A2-Mab-sepharose was 99% in buffer, while it was 88-82% in serum. The binding efficiency of (111)In-DTPA-rFVIIa to TF (1-209)-sepharose was 48% in buffer whereas 39%-36% in serum, respectively. In vivo experiment was conducted in healthy rats, and gamma camera images were taken immediately after iv. administration of 1.6-1.8 MBq (111)In-DTPA-rFVIIa up to 120-130 min. Five min after administration of (111)In-DTPA-rFVIIa, percentage of (111)In activity was 6.0% in the cardiac region and 24.5% in the liver region. After 2 hours activity was decreased to 3.3% in heart while it had increased to 42.0% in the liver. The (111)In-DTPA-rFVIIa might be a potential radiopharmaceutical for visualisation of tissues with significant TF expression such as acute bleeding lesions in the gastrointestinal tract.
authors.affiliation: Institute of Biomedical Sciences, Faculty of Health Sciences, University of Copenhagen, DK-2200, Copenhagen, Denmark.
authors.forename: Amarnadh
authors.initials: A
authors.lastname: Nalla
authors.forename: Inge
authors.initials: I
authors.lastname: Buch
authors.forename: Maibritt
authors.initials: M
authors.lastname: Sigvardt
authors.forename: Rasmus Poul
authors.initials: RP
authors.lastname: Bodholdt
authors.forename: Andreas
authors.initials: A
authors.lastname: Kjaer
authors.forename: Birger
authors.initials: B
authors.lastname: Hesse