Figure 4.

Metabolic perturbation during receptor ligation. NAD(P)H fluorescence (A and C) and Fl-FNLPNTL fluorescence (B) micrographs are shown. Images in A and C were collected for 2.5 ms with a 100-ms interval between frames. In B, the images were collected for 2.5 ms each, but the interval time varied to illustrate the injection, dissipation, and labeling with the Fl-FNLPNTL, a fluorescent FPR agonist (total time is ≈1 min). (A) In the absence of extracellular perturbation, singular traveling waves are observed. (B) A micropipet was charged with 50 nM Fl-FNLPNTL. The micropipet's tip was brought to within a few μm of a polarized and PMA-primed neutrophil. A small quantity of Fl-FNLPNTL was expelled toward the cell's side (arrow in frames 1 and 7). Fl-FNLPNTL preferentially labeled the membrane near the pipet (frame 7). (C) The NAD(P)H intensity pattern realigned to match the region of Fl-FNLPNTL binding (2.5 ms per image with a 100-ms interval between images. Moreover, two NAD(P)H waves are now observed. The direction of FMLP injection is given by the arrow in frame 1. (The increase in the noise of C compared with A is because of the reduction in the waves' intensity.) (n = 17; ×890.)