Histopathologic correlates of serum amylase activity in acute experimental pancreatitis

The association of serum amylase activity with the extent of pancreatic injury in acute pancreatitis is unclear. To clarify this relationship, we induced acute pancreatitis ranging from mild to lethal in 118 Sprague-Dawley rats (350–450 g). This was achieved by controlled intraductal infusion of low- or high-dose bile salt, with or without enterokinase, followed by intravenous cerulein or saline for 6 hr. Serum amylase was measured at baseline and 6 hr. Pancreatic histopathology was evaluated by two blinded pathologists employing total surface scoring (N=118) and morphometric 20-field documentation (N =22). Serum amylase correlated best with edema (r=0.61) and fat necrosis (r=0.58), less well with acinar necrosis (r=0.53) and inflammation (r=0.50), and poorly with hemorrhage (r=0.33) and perivascular infiltrate (r=0.31). Inasmuch as edema and fat necrosis are not important determinants of severity, these observations could explain the poor prognostic value of serum amylase activity in patients with acute pancreatitis.J. Schmidt was supported by grants from Deutsche Forschungsgemeinschaft No. Schm 781/1-1+2 and C. Fernandez-del Castillo was supported by Boehringer Foundation, Mexico.Preliminary results of this research have been presented in part at the Annual Meeting of the American Gastroenterological Association, New Orleans, May 19–22, 1991.