| Abstract: | We previously reported that water-immersionstress specifically induced the synthesis of a 60-kDaheat-shock protein (HSP60, chaperonin homolog) inpancreatic cells and preinduction of HSP60 completely prevented development of cerulein-inducedpancreatitis in the rat in an HSP60 quantitativelydependent manner. In order to study the cytoprotectivefunction of a 72-kDa heat-shock protein (HSP72,stress-inducible hsp70), the effect of specific preinduction ofHSP72 by hyperthermia on cerulein-induced pancreatitiswas investigated and compared with the effect ofpreinduction of HSP60 in this study. Expression of HSP60 and HSP72 in the pancreas wasinvestigated by immunoblot before and after waterimmersion or hyperthermia. Following pretreatment withwater-immersion stress or hyperthermia, the rats wereinjected with cerulein (40  g/kg, intraperitoneally).The pancreas wet weight and serum amylase concentrationwere measured before and after cerulein injection.Hyperthermia (42.5°C, 20 min) specifically induced HSP72 in the pancreas. The synthesis of HSP60was specifically induced by water-immersion stress inthe pancreas. Cerulein-induced pancreatitis was clearlyprevented by specific preinduction of HSP60 by water-immersion stress. However, preinductionof HSP72 by hyperthermia had no preventive effect oncerulein-induced pancreatitis. Our findings suggest thatHSP60 and HSP72 have distinct functions in the pancreas, and their induction mechanisms arealso different in vivo. These results could be importantfor understanding the mechanism of  adaptivecytoprotection in the pancreas mediated byheat-shock proteins. |
