Pancreastatin-like immunoreactivity in urine.

The concentration and molecular form of pancreastatin-like immunoreactivity (PST-LI) in urine of normal subjects and patients with noninsulin-dependent diabetes mellitus or chronic renal failure were examined. PST-LI output (mean +/- SEM) in urine of normal subjects was 74.6 +/- 8.5 pmol/day and 87.1 +/- 11.7 pmol/g creatinine. That in patients with noninsulin-dependent diabetes mellitus was 78.1 +/- 9.0 (SEM) pmol/day and 85.6 +/- 9.0 pmol/g creatinine and was not significantly different from that in normal subjects. Gel filtration analysis showed that PST-LI molecules excreted in urine of these two groups were smaller than human pancreastatin (43-52) (hPST-10) of C-terminal fragment. The PST-LI molecular forms were deduced to be nonbioactive from the result that hPST-10 did not inhibit pancreatic exocrine secretion. PST-LI excretion in patients with chronic renal failure was 258.5 +/- 62.9 pmol/day and 713.2 +/- 219.6 pmol/g creatinine. A molecular form corresponding to hPST-52 and a larger form eluted in the high mol wt region (approximately mol wt 15 K) were detected by gel filtration of urine from these patients, indicating that PST-LI is excreted in urine without degradation in patients with chronic renal failure. These results support the suggestion that the kidney may play an important role in PST degradation or metabolism.