Radiation effects on circulating and endothelial cell interactions studied by quantitative real-time videomicroscopy.
OBJECTIVE
To quantify in vitro the functional consequences of irradiation on the interactions between leukocytes or platelets and endothelial cells (EC) in flowing whole blood using a parallel-plate flow chamber and real-time videomicroscopy.


METHODS
The parallel-plate flow chamber was calibrated to determine the dynamic parameters of the flow channel. Fluorescent-labelled whole blood was perfused at wall shear rates of 25, 75 and 500 s(-1) over a monolayer of human microvascular EC-lung (HMVEC-L) with or without irradiation at 10 Gy. The adhesion of leukocytes and platelets on EC was quantified by videomicroscopy and image analysis.


RESULTS
Calibration of the parallel-plate flow chamber showed that flow in the chamber was laminar and steady and had a parabolic velocity profile, thus simulating physiological flow conditions. Flow assay revealed that rolling, mean rolling velocity and firm adhesion of leukocytes was increased following irradiation of EC. Irradiation also favoured platelet adhesion to EC.


CONCLUSIONS
The results of an in vitro flow assay with whole blood showed that under physiological flow conditions, irradiation affected the function of EC; pro-inflammatory and thrombogenic responses were enhanced, which may contribute to in vivo radiation-induced vascular occlusion and fibrosis.
Vereycken-Holler
V
V
Institut de Radioprotection et de Sureté Nucléaire, Département de Protection de la santé de l'Homme et de Dosimétrie, Section Autonome de Radiobiologie Appliquée à la Médecine, IRSN, B.P. no. 17, F-92262 Fontenay-aux-Roses cedex, France.
Aigueperse
J
J
Gaugler
M H
MH
D001792:Blood Platelets / Q000528:radiation effects; D002138:Calibration; D002448:Cell Adhesion; D002478:Cells, Cultured; D004730:Endothelium, Vascular / Q000166:cytology* / Q000528:radiation effects*; D005355:Fibrosis; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007962:Leukocytes / Q000528:radiation effects; D008168:Lung / Q000098:blood supply; D008833:Microcirculation; D018715:Microscopy, Video / Q000379:methods*; D013314:Stress, Mechanical; D013997:Time Factors