Absence of effects on platelet membrane fluidity by antibiotics in ESR spectra

The effect of several antibiotics on rat platelet membrane fluidity was examined by ESR spectrometry using 5-doxyl stearate as the spin probe. Latamoxef, cefamandole, cefotaxime and carbenicillin had negligible effects on the order parameters, the indices of membrane fluidity, of platelet-rich plasma or washed platelets at high concentrations that would inhibit ADP-induced rat platelet aggregation in vitro. A further in vivo study with one of these antibiotics, latamoxef, showed no significant effect on the fluidity based on ESR data.