SERUM AND URINARY PANCREATIC SECRETORY TRYPSIN INHIBITOR CONCENTRATION IN PATIENTS WITH CHRONIC RENAL FAILURE

Abstract

Quantitative examination of serum pancreatic secretory trypsin inhibitor (PSTI) was performed in order to clarify the mechanism of abnormal elevation of serum PSTI levels in patients with chronic renal failure (CRF). There found no substances that interfere PSTI-radioimmunoassay (RIA) system. Dilution curves of serum and urine of the patients with CRF were parallel with standard curve for PSTI, and recovery of exogeneous PSTI added to serum and urine of CRF was 102.6±1.6% and 108.8±1.6%, respectively. Moreover, elution profile of serum PSTI from patients with CRF through Sephadex G-200 column was the same as that of PSTI in normal subject. Taken together with the previous our observations that denied excess production of PSTI from pancreas in patients with CRF, these results indicate that reduced renal clearance of PSTI is the main reason for abnormal elevation of serum PSTI levels in patients with CRF. However, urinary PSTI excretion was markedly increased in patients with CRF and inversely correlated with creatinine clearance. These findings could not be explained simply by the reduced glomerular filtration of PSTI in CRF but suggested production of PSTI in kidney.
The present observations suggest that elevation of serum PSTI levels in CRF is mainly due to reduced renal clearance of PSTI and additionally to renal production of PSTI.