FIGURE 6.

Supraphysiologic caerulein affects neither cathepsin L activity nor protein amount or its precursor procathepsin L, whereas depleting procathepsin B. A, cathepsin L activity under the mentioned conditions shows no significant changes. Bas, basal activity. B, WB of lysates from murine pancreatic acini treated for 30 min with 0.1 μm caerulein (0.1 μm CER) shows the depletion of 34-kDa procathepsin B, which is prevented by 50 μm BFA. Concomitant with the depletion of procathepsin B (proCath B) by 0.1 μm caerulein, its propeptide appears in the acinar cell homogenates in the form of a 6-kDa fragment. Lipase is shown as a loading control. Cath B, cathepsin B. C, WB of lysates from murine pancreatic acini treated for 30 min with 0.1 μm caerulein shows that this does not induce depletion of 42-kDa procathepsin L or change the amounts of mature (25 kDa) cathepsin L (Cath L).