p38 map kinase is expressed in the pancreas and is immediately activated following cerulein hyperstimulation

Background: The pathophysiology of pancreatitis and the pancreatic stress r esponse are not well understood. In the pancreas, mitogen-activated protein kinase (MAPK) and stress-activated protein kinase (SAPK) are reportedly re gulated by secretagogue stimulation and hyperstimulation. However, no data exist on the expression and regulation of pancreatic p38 Map kinase. Aims: Pancreatic expression of p38 Map kinase and MAPK, SAPK and p38 regulation d uring pancreatic stress were investigated. Methods: For hyperstimulation an d secretory stress, cerulein was given intravenously, while hype rf he rm i a preconditioning stress was induced by who le body hyperthermia (42 degree s C). Results: In addition to MAPK and SAPK, p38 Map kinase was found to be expressed in the rat pancreas. Cerulein regulated all kinases time- and do se-dependently. MAPK and p38 Map kinase showed basal activity and were furt her activated at low cerulein doses. SAPK had no basal activity and its act ivation required maximal secretory to supramaximal amounts of cerulein. Cer ulein hyperstimulation, inducing pancreatitis, activated p38 more rapidly t han SAPK and more strongly than MAPK. In contrast to cerulein hyperstimulat ion stress, hyperthermia stress only activated p38 Map kinase. Conclusions: p38 Map kinase is expressed in the pancreas and is most rapidly activated following cerulein hyperstimulation. Both SAPK and p38 Map kinase are possi bly important regulators during the onset of cerulein pancreatitis.