Induction of HSP72 by sodium arsenite fails to protect against cholecystokinin-octapeptide-induced acute pancreatitis in rats

Abstract

A number of investigators have demonstrated that the preinduction of heat-shock protein (HSP) expression (particularly HSP60 and HSP72) by hyper- or hypothermia may have a protective effect against cerulein-induced acute pancreatitis. The aim of the present study was to induce HSPs in the pancreas and lungs by thermal (hot-water immersion, HWI) and nonthermal methods (injection of sodium arsenite intraperitoneally) and to investigate the potential effects of HSP preinduction on cholecystokinin-octapeptide (CCK) induced acute pancreatitis and pancreatitis-associated lung injury in rats. The dose-response and time-effect curves observed following HWI and sodium arsenite treatments were evaluated. Animals were injected with 3 x 75 microg/kg CCK subcutaneously at intervals of 2 hr at the peak level of HSP synthesis, as determined by Western blot analysis. The rats were killed by exsanguination through the abdominal aorta 2 or 6 hr after the last CCK injection. HWI and the injection of sodium arsenite significantly elevated the expression of HSP72 in the pancreas and lungs, whereas they did not influence the levels of HSP60. Overall, HWI pretreatment had a protective effect against CCK-induced pancreatitis and pancreatitis-associated lung injury. In contrast, the nonthermal preinduction of HSP72 by sodium arsenite did not result in any beneficial effects on the measured parameters of the disease. The findings suggest that the preinduction of HSP72 is not sufficient to protect against CCK-induced acute pancreatitis and pancreatitis-associated lung injury or that the beneficial effect of hyperthermia may not be exclusively related to HSP72 expression.