Stress kinase inhibition modulates acute experimental pancreatitis

Figure 1 Effects of CEP1347 and SB203580 on acinar stimulus secretion coupling and trypsin activation. Acutely isolated acini were incubated with the indicated amounts of cerulein for 30 min (●). Acini were also treated with 20 μM CEP1347 (▽), 50 μM SB203580 (▼) or both agents simultaneously (○). A: Amylase release into the supernatant was determined and expressed as % of total content. Stimulus secretion coupling was not significantly altered by stress kinase inhibitors. B: Active trypsin was measured in acinar homogenates and expressed as pg/mg protein. Although SB203580 treated acini had a tendency towards higher amounts of active trypsin, this effect was not statistically significant.

Figure 2 SB203580 inhibits cerulein-induced p38 kinase activation in vivo. Animals were treated with the indicated amounts of SB203580, sc, 2 h prior to cerulein hyperstimulation. In vitro phosphorylation of HSP27 following immunoprecipitation of MAPKAPK2 was used as read-out of p38 activity. 30 mg SB203580 almost completely abolished cerulein-induced pancreatic p38 activation.

Figure 3 Effects of CEP1347 and SB203580 on biochemical parameters of pancreatitis. Animals were treated with 10 μg/kg cerulein iv and sacrificed 2 h later. As indicated rats were also pretreated with 30 mg/kg CEP1347 and/or SB203580 4 h prior to cerulein injections. Serum amylase levels (A), serum lipase levels (B), dry to pancreatic total weight ratio (C) and pancreatic active trypsin content (D) were determined after sacrifice. Kinase inhibitors had no apparent effect on the cerulein-induced increase of serum digestive enzyme levels. However, CEP1347 reduced the cerulein-induced increase of pancreatic water content and this effect was blocked by simultaneous treatment with SB203580. SB203580 further increased cerulein induced pancreatic active trypsin content and this effect was blocked by simultaneous treatment with CEP1347.

Figure 4 SB203580 treatment leads to necrosis development during cerulein pancreatitis. Animals were treated as in Figure 3. Pancreata were then removed and tissue sections HE stained for light microscopy. untreated control, cerulein alone, 30 mg/kg CEP1347 4 h prior to cerulein, 30 mg/kg CEP1347 and SB203580 prior to cerulein, and 30 mg/kg SB203580 prior to cerulein. Original magnification 50 fold (A-E). Panel F shows a higher (150-fold) magnification of panel E.