title: Quantification of the Blood Platelet Reactivity in the ADP-Induced Model of Non-Lethal Pulmonary Thromboembolism in Mice with the Use of Laser Doppler Flowmetry.
abstract: BACKGROUND
  The paper describes an alternative method for quantification of in vivo ADP-induced thromboembolism. The aim of the studies was to develop a method of quantification which would not require either extravasation or labelling of platelets. Our proposed approach is based on the monitoring of changes of blood flow with the use of laser Doppler flowmetry.
  
  
  METHODS
  Mice of C57Bl strain were used in the study. ADP was injected to the vena cava and blood flow was monitored with the use of a laser Doppler flowmeter in the mesentery. Measurements in platelet-depleted mice, mice pretreated with cangrelor, an ADP receptor antagonist, and eptifibatide, a blocker of fibrinogen binding to GPIIbIIIa, were conducted as the proof-of-concept in the performed experiments. Intravital microscopy and ex vivo imaging of organs was performed to identify the sites of aggregate formation resulting from ADP injection.
  
  
  RESULTS
  The injection of ADP resulted in a dose-dependent reduction of the blood flow in the mesentery. These responses were fully attributable to blood platelet aggregation, as shown by the lack of the effect in platelet-depleted mice, and significantly reduced responses in mice pretreated with cangrelor and eptifibatide. No platelet aggregate formation in mesenteric vessels was revealed by intravital microscopy, while ex vivo imaging showed accumulation of fluorescent labelled platelets in the lung.
  
  
  CONCLUSIONS
  Injection of ADP to the venous system results in the formation of platelet aggregates predominantly in the lung. This results in reversible blood flow cessation in peripheral blood vessels. The measurement of this blood flow cessation in the mesentery allows indirect measurement of ADP-induced pulmonary thromboembolism. We suggest that this approach can be useful for in vivo screening for antiplatelet drug candidates.
authors.affiliation: Department of Haemostasis and Haemostatic Disorders, Chair of Biomedical Sciences, Medical University of Lodz, Lodz, Poland.
authors.forename: Tomasz
authors.initials: T
authors.lastname: Przygodzki
authors.affiliation: Department of Haemostasis and Haemostatic Disorders, Chair of Biomedical Sciences, Medical University of Lodz, Lodz, Poland.
authors.forename: Marcin
authors.initials: M
authors.lastname: Talar
authors.affiliation: Ludwik Hirszfeld Institute of Immunology and Experimental Therapy, Polish Academy of Sciences, Wroclaw, Poland.
authors.forename: Agnieszka
authors.initials: A
authors.lastname: Blazejczyk
authors.affiliation: Department of Veterinary Resources, Weizmann Institute of Science, Rehovot, Israel.
authors.forename: Vyacheslav
authors.initials: V
authors.lastname: Kalchenko
authors.affiliation: Department of Haemostasis and Haemostatic Disorders, Chair of Biomedical Sciences, Medical University of Lodz, Lodz, Poland.
authors.forename: Cezary
authors.initials: C
authors.lastname: Watala
mesh_terms: D000244:Adenosine Diphosphate / Q000009:adverse effects*; D000249:Adenosine Monophosphate / Q000031:analogs & derivatives / Q000737:chemistry; D000818:Animals; D019540:Area Under Curve; D001792:Blood Platelets / Q000166:cytology*; D000077542:Eptifibatide; D000069416:Intravital Microscopy; D017078:Laser-Doppler Flowmetry; D008168:Lung / Q000503:physiopathology; D008297:Male; D008643:Mesentery / Q000503:physiopathology; D051379:Mice; D008810:Mice, Inbred C57BL; D008856:Microscopy, Fluorescence; D010455:Peptides / Q000737:chemistry; D010974:Platelet Aggregation / Q000187:drug effects; D010975:Platelet Aggregation Inhibitors / Q000737:chemistry; D019039:Platelet Glycoprotein GPIIb-IIIa Complex / Q000737:chemistry; D011655:Pulmonary Embolism / Q000139:chemically induced / Q000503:physiopathology*; D013921:Thrombocytopenia / Q000503:physiopathology
chemical_list: D010455:Peptides; D010975:Platelet Aggregation Inhibitors; D019039:Platelet Glycoprotein GPIIb-IIIa Complex; D000249:Adenosine Monophosphate; D000244:Adenosine Diphosphate; C117446:cangrelor; D000077542:Eptifibatide