SERUM SAMPLES FROM PANCREATECTOMIZED PATIENTS CONTAIN TRYPSINOGEN IMMUNOREACTIVITY

The concentrations of trypsinogen-1 and -2 in serum samples from patie nts who have undergone pancreatectomy were measured by highly sensitiv e and specific time-resolved immunofluorometric assays. The isoenzyme pattern was determined by ion-exchange chromatography and determinatio n of immunoreactivity in the fractions. All samples contained trypsino gen-2, the mean level being one fifth of that in healthy controls. Try psinogen-1 was detected in one of nine samples. In addition to the mai n trypsinogen isoenzymes, we observed in normal serum two trypsinogen isoenzymes previously found in mucinous ovarian cyst fluid. Our result s suggest that trypsinogen is not exclusively expressed by the pancrea s and certain tumors but that it also may be produced by normal extrap ancreatic tissues. This should be considered when an assay of trypsino gen in serum is used for clinical purposes.