Figure 2.

Saliva production decreases over time in WT mice but not in KO mice that lack the type I IFN signaling pathway. Pilocarpine-induced saliva production was measured at the different ages indicated in the Fig. Data are represented as the ratio of saliva volume (µL) to body weight (gm). Student’s t test was used to determine statistical significance. Saliva volumes (mean ± SEM) in WT mice at 15 to 18 wks (3.65 ± 0.21) and 19 to 22 wks (2.83 ±0.28) were significantly lower compared with those at 11 to 13 wks (5.93 ± 0.46) of age, indicating a progressive loss of function. In contrast, in KO mice, the mean saliva volumes between early and late ages were not different. Although WT and KO mice had comparable saliva production at 11 to 13 wks of age, the differences between the 2 groups were highly significant at the 15 to 18-week (p < .0001) and 19- to 22-week (p < .0001) time-points.