Iodine-125-fibrinogen kinetics in the rabbit arterial wall.

Elevated fibrinogen has been claimed as an independent risk factor for the development of atherosclerosis. Incorporation of fibrinogen into human atherosclerotic lesions has been demonstrated. We assessed in a rabbit model of experimental atherosclerosis, biodistribution as well as kinetics and vascular uptake of (125)I-fibrinogen. Rabbits aged 6 months were fed a 1% cholesterol supplemented diet. After experimental de-endothelialization of rabbit aorta using a Fogarthy catheter, (125)I-fibrinogen uptake was enhanced by more than one order of magnitude as compared to intact segments covered by endothelium. Six rabbits per group were examined. Even re-endothelialized segments showed a significantly higher uptake of the radiolabeled protein. Maximum arterial uptake varied between 12 (de- and re-endothelialized segments) and 24h (intact areas) after injection of (125)I-fibrinogen. In conclusion, these experiments for the first time suggest the increased uptake of radiolabeled fibrinogen in the aortic de-endothelized wall in rabbits.