Figure 5.

A: an example time course of an isometric force experiment for an airway ring before and after riboflavin and UV-A treatment. Airway rings were stimulated with EFS three times for 10 s and left to return to their baseline force, then exposed to 10⁻⁵M ACh for 5 min. B: the baseline force and active force generated by each airway ring in response to 10⁻⁵ M ACh (n = 10) before (white) and after (dark gray) collagen crosslinking. The increase in force due to ACh was statistically significant for pretreatment (P = 0.002, Wilcoxon Signed Rank test, n = 10) and posttreatment (P = 0.001, paired t test, n = 10) airway rings. C: the percentage increase from baseline force after ACh exposure for airway rings before (pretreatment, white triangles, n = 10) and after (posttreatment, dark gray triangles, n = 10) riboflavin and UV-A treatment. The difference in the percentage increase from baseline force after 5 min of ACh exposure between pretreatment and posttreatment airway rings was statistically significant (P = 0.006, paired t test, n = 10). D: the percentage increase from baseline force after ACh exposure in control airway rings that were not treated with riboflavin and UV-A. No statistical differences were observed between the first (white triangles, n = 8) and second constriction (dark gray triangles, n = 8) experiments (P = 0.760, paired t test, n = 8). n, number of airway rings tested; *statistical significance (P < 0.05).