Fig 5. Mucin secretory response of HBECCs to liquid shear stress.

HBECCs were perfused luminally at 100 μl/min during 2 h equilibration and 10 min baseline collection periods, then the perfusion rate was increased in a single step (arrow) by 2.5, 5, or 10 fold. Fractions collected during the baseline and increased flow periods were assessed for secreted mucins by the WGA ELLA. A. Time course showing the effects of a 5-fold increase (jump) in flow rate. Mucin secretion is plotted as mucin content/fraction, normalized to baseline (mean ± SE, n = 5). B. Relationship between the magnitude of the change in flow rate, and the normalized peak and integrated mucin secretory responses. The normalized peak and 30 min, integrated mucin secretory responses from the cultures subjected to different changes in flow-induced shear stress are plotted against the jump in flow rate. The abscissa shows the final flow rates, fold jump in flow, and the calculated, final steady-state shear stresses at each final flow rate used. Each point represents the mean ± SE of 5 or more experiments.