抄録
In pancreatic acinar cells, Ca2+/calmodulin-dependent protein kinase (CaM-kinase) type II is activated by cholecystokinin (CCK) -8 in a dosedependent manner, whereas amylase secretion is inhibited by supramaximal doses of CCK-8. Bradykinin appears to be involved in exacerbation of caerulein-induced pancreatitis. In endothelial cells, filamin translocation, which is responsible for bradykinin release in the early inflammatory phase, is initiated by CaM-kinase II. Activation of CaM-kinase II in pancreatic acinar cells is therefore potentially involved in caerulein-induced pancreatitis. The aim of this study was to investigate whether CaM-kinase II plays an important role in caerulein-induced pancreatitis. Rats were given 4 intraperitoneal (i.p.) injections of caerulein. CaM-kinase II activity was measured by the rate of incorporation of [γ-32P] ATP with autocamtide II as a specific substrate. CaM-kinase II was also detected by immunohistochemistry. At 6 hours after the initial i.p. injection of caerulein, the maximal pancreatic damage was histologically observed and maximal pancreatic tissue weight and minimal pancreatic protein content were found. Serum amylase levels were significantly elevated from 6 to 9 hours. The maximal CaM-kinase II activity was observed and acinar cells were intensely immunoreactive for CaM-kinase II at 6 hours. KN-62, a selective CaM-kinase II inhibitor, had a preventive effect on edema and vacuolization and significantly reduced serum amylase levels during pancreatitis. This study indicates that activation of CaM-kinase II in pancreatic acinar cells plays a crucial role in the early phase of caerulein-induced pancreatitis.
