Abstract 13183: A Novel Model of in vivo Platelet Thrombus Imaging Using CD41-ZsGreen1 Transgenic Rats
Introduction: Platelets play important roles in both hemostasis and thrombotic diseases including myocardial and cerebral infarction, and stent thrombosis. While mice models of in vivo fluorescence imaging have been described, there are few suitable in vivo models for platelet imaging in rats which are commonly used as thrombosis models. The objective of this study was to generate fluorescent platelets and assess their dynamics in injured arteries in rats.
Methods: We generated CD41-ZsGreen1 transgenic (TG) rats, in which the green fluorescence protein ZsGreen1 was expressed specifically in megakaryocytes and thus platelets, and evaluated platelet dynamics in in vivo thrombus imaging experiments. Hematological, including platelet aggregation and blood clotting time, and biochemical parameters were analysed. In the imaging experiments, saphenous arteries of TG rats were injured with 10% FeCl3, and thrombus formation was evaluated as fluorescence accumulation using confocal microscopy. The effect of prasugrel, a thienopyridine ADP receptor antagonist, on thrombus formation was also evaluated.
Results: The CD41-ZsGreen1 TG rats exhibited normal hematological and biochemical values with the exception of body weight and erythroid parameters, which were significantly lower than those in wild type (WT) rats. Platelet aggregation, induced by 20 μM ADP or 10 μg/mL collagen, and blood clotting times (APTT and PT) were not significantly different between TG and WT rats. In thrombus formation experiments, FeCl3 application caused a time-dependent increase in fluorescence intensity in the injured artery in vehicle-treated rats. Prasugrel at an oral dose of 3 mg/kg, treated 2 h before the FeCl3 application, significantly inhibited fluorescence accumulation compared to the vehicle-treatment group (14.9±2.4 vs 5.4±0.4 arbitrary fluorescence unit at 30 min for vehicle and prasugrel groups, respectively, n=8, p=0.0037).
Conclusions: CD41-ZsGreen1 TG rats represent a useful animal for the in vivo imaging of platelet participation in thrombus formation and the evaluation of antithrombotic agents.
Author Disclosures: M. Mizuno: Employment; Significant; Daiichi Sankyo Co., Ltd. A. Tomizawa: Employment; Significant; Daiichi Sankyo Co., Ltd. K. Ohno: Employment; Significant; Daiichi Sankyo Co., Ltd. J. Jakubowski: Employment; Significant; Eli Lilly and Company. A. Sugidachi: Employment; Significant; Daiichi Sankyo Co., Ltd..
- © 2015 by American Heart Association, Inc.