Figure 7.
Wfh% plotted against the influence of DIDS on the Cl– secretory response, calculated as the difference between the carbachol response before the incubation of the tissue with DIDS, and the histamine response in the presence of DIDS. Values are plotted for siblings of CONmild (filled circles) pairs, CONsevere (open circles) pairs, and the mildly affected and severely affected siblings of DISC pairs (DISCmild, filled triangles; and DISCsevere, open triangles). All CONmild and DISCmild siblings except one exhibited either a small negative or even a positive influence of DIDS, meaning that DIDS did not inhibit Cl– secretion in these individuals. In contrast, DIDS inhibited the majority of Cl– secretory responses of the CONsevere and DISCsevere siblings. This negative DIDS influence correlated significantly with the CONsevere and DISCsevere patients (P = 0.03, Fisher’s exact test). Moreover, the magnitude of wfh% correlated with the magnitude of the DIDS influence (P < 0.025, Spearman’s test).