Trypsin inhibitor ingestion-induced urinary indican excretion and pancreatic acinar cell hypertrophy.

Sodium saccharin (NaSacc) has been shown to be a protease inhibitor and to induce an increase in urinary indican, which is a product that is dependent on microbial metabolism of tryptophan. These findings suggest that urinary indican might provide a noninvasive marker of increased pancreatic acinar cell size associated with plant trypsin inhibitor ingestion. The results demonstrate the 7.5% of dietary NaSacc, which increases urinary indican, also increases relative pancreas mass (g/kg body weight), and that these effects are not induced by intravenous infusion of NaSacc. Dietary soybean trypsin inhibitor in the dose range of 17-713 mg/100 g diet was associated with parallel dose-dependent increases in urinary indican and pancreatic acinar cell size (assessed histologically). These findings suggest that measurement of relative urinary indican excretion (microgram/g diet ingested) can provide a noninvasive marker of increased pancreatic acinar cell size in rats that ingest compounds which inhibit digestive proteases.