Fig. 4.

A: representative trace demonstrates the effect of arachidonic acid (AA, 100 μM) on the Ca²⁺ fluorescence ratio in PSCs. AA produced a sustained and robust increase in intracellular calcium mobilization responses (F340/F380 ratio) in PSCs harvested from HFA-fed rats (top trace). Cells were isolated from male Lewis rats fed HFA for 6–8 wk and placed in culture for 3 days. Calcium mobilization was seen in 48 of 70 PSCs in response to bath application of AA. In contrast, bath application of AA evoked no response or minimal response in PSCs (16 of 72) prepared from naïve control Lewis rats (bottom trace). B: change in peak fluorescence response ratio after AA was summarized as a concentration-response relationship. The strong activation response of PSCs taken from pancreas of HFA-fed rats increased in a dose-dependent manner (■, top line), while a minimal response was recorded from PSCs isolated from pancreas of control rats (□, bottom line). (***P < 0.001, two-way ANOVA, Bonferroni post hoc test). C: table shows the total number of PSCs tested and percentage of total cells activated by AA in both HFA fed and control rats.