A rapid, quantitative method for measuring leukocyte adhesion to normal and balloon-injured arteries in vitro

Many of the currently available techniques for quantifying leukocyte adhesi on require monolayers of cells and are therefore unsuitable for use in ex v ivo arterial tissue. Here we describe a rapid method to measure adhesion of leukocytes to intact artery strips and to determine the effect of artery i njury on adhesiveness of leukocytes with and without activation. Leukocytes were isolated from rabbit blood, labelled with Cr-51, and added to the lum inal face of the left and right subclavian arteries derived from the same a nimal. In some experiments the endothelium was removed before addition of l eukocytes and in another series of experiments the artery was injured by in flating a balloon catheter within the lumen in vitro before leukocyte addit ion. After washing, the adhesion of labelled leukocytes was quantified by g amma counting. To determine localization of the leukocytes, some arteries w ere fixed in situ and examined microscopically, with confirmation of leukoc yte identification by enzyme cytochemistry. The adhesion of leukocytes incr eased progressively during 60 min and was inhibited by reducing the tempera ture to 4 degreesC. Adhesion was increased by the nitric oxide synthase inh ibitor L-NAME. Stretching the artery wall in vitro using a balloon catheter increased leukocyte adhesion within 1 h after injury. In contrast, this di d not occur following simple arterial denudation. Histological examination of stained en face preparations and transverse sections of the subclavian a rteries revealed loosely adherent granulocytic leukocytes on the endothelia l surface. This technique is straightforward and allows. accurate and rapid measurement of autologous leukocyte adhesion to normal and pathologically altered arteries ex vivo. (C) 2000 Elsevier Science B.V. All rights reserve d.