Flow cytometry analysis of human neutrophils labeled with rhodamine phalloidin: effect of pentoxifylline.
Pentoxifylline (PTX) has been reported to enhance the early accumulation of neutrophils at the site of Staphylococcus aureus subcutaneous infection in mice (1) and to stimulate in vitro PMN chemotaxis, particularly under dense agarose (2). Among the biochemical events contributing to chemotaxis are actin polymerization (3). The membrane cytoskeleton is believed to control the lateral mobility of integral membrane proteins as well as influencing cell shape and mobility. Thus, pharmacological modulations of neutrophil chemotaxis may be related to an effect of the pharmacological agents on the membrane cytoskeleton. The present study was designed to characterize the effect of PTX on actin polymerization of freely-suspended PMN before and after stimulation by the chemotactic factor f-MLP. We used flow cytometry to determine the proportion of actin in the filamentous form, and Rhodamine-Phalloidin as fluorescent probe (4). PTX decreased actin polymerization in response to stimulation by f-MLP. The reduction in F-actin by PTX was higher in the samples with higher activation ratios as compared with untreated PMN.
Freyburger
G
G
Laboratoire d'Hémobiologie - INSERM U 8, Pessac-Bordeaux-France.
Belloc
F
F
Boisseau
M R
MR
D000199:Actins / Q000502:physiology; D005434:Flow Cytometry; D005456:Fluorescent Dyes; D006801:Humans; D009240:N-Formylmethionine Leucyl-Phenylalanine / Q000494:pharmacology; D009504:Neutrophils / Q000187:drug effects*; D010431:Pentoxifylline / Q000494:pharmacology*; D013268:Stimulation, Chemical
D000199:Actins; D005456:Fluorescent Dyes; D009240:N-Formylmethionine Leucyl-Phenylalanine; D010431:Pentoxifylline