QUICK SEARCH:   [advanced] Author: Keyword(s):
Home     Help     Feedback     Subscriptions     Archive     Search     Table of Contents

Help viewing high resolution images Return to article

Fig. 5. PAF-stimulated cytosolic alkalinization is not blocked by inhibiting known proton-efflux mechanisms. Purified human eosinophils were loaded with BCECF/AM and stimulated with media control or PAF (3 µM) in the presence or absence of EIPA (100 µM), Zn²⁺ (250 µM), bafilomycin (2.5 µM), or folimycin (2.5 µM) at 37°C. Fluorescence was measured over 90 minutes and was converted to pH_i using a standard curve as described in Materials and Methods. Data are shown as mean±s.e.m. (A) Eosinophils stimulated with media alone (n=5) showed no significant changes in pH_i compared with pH_i at time 0. Eosinophils stimulated with PAF alone (n=3) or in the presence of EIPA (n=3), Na⁺-free media (n=3) or Zn²⁺ (n=3) as indicated, all show significant alkalinization compared to pH_i at time 0. Initial pH_i values for EIPA, Na⁺-free media, and Zn²⁺ data sets were 6.8±0.0, 6.9±0.1 and 6.7±0.0, respectively. None of the inhibitors resulted in a final pH_i that was significantly different from that induced by PAF alone. (B) Eosinophils stimulated with media control (n=6) showed no significant changes in pH_i compared with pH_i values at time 0. Eosinophils stimulated with PAF alone (n=7) or in the presence of bafilomycin (n=7) or folimycin (n=5) showed similar levels of alkalinization. Initial pH_i values for media control, PAF, PAF + bafilomycin and PAF + folimycin data sets were all 7.0±0.1. There were no significant differences in final pH_i in when cells were stimulated with PAF, PAF + bafilomycin or PAF + folimycin. ^*P<0.01 (compared to pH_i at time 0); n.s., not statistically different.

Return to article