FIGURE 2.
Partial exposure to ammonia. (A, top panel) Transmission image of a guinea-pig myocyte; vertical arrows show direction of microstream flow; vertical dashed line shows position of solution boundary; horizontal double-headed arrow shows direction in which solution boundary was moved during the course of the experiment. (A, bottom panel) Time-averaged confocal images collected in the steady-state period before and during 60, 20, and 85% partial exposure of the myocyte to 10 mM ammonium under Hepes-buffered conditions. (Bi) Transmission image of the myocyte showing the location of ROIs within which pHi time courses were averaged. (Bii) Experimental data showing pHi time courses in the three ROIs during the entire partial perfusion experiment. (Biii) Simulation of experimental data obtained from diffusion-reaction algorithms, assuming no sarcolemmal NHE activity and no carbonic buffer. (Ci) Experimental data for the longitudinal end-to-end pHi profiles plotted along the length of the cell during 60, 20, and 85% partial perfusion with 10 mM ammonium. (Cii) These longitudinal pHi profiles have been simulated using diffusion-reaction algorithms.