The Effects of Trypsin Inhibitor on Insulin Secretion Using Rat Pancreas in an Organ Bath

Effect of TI on trypsin activity. Trypsin activity at baseline (A) and the end (B) of the experiment. Data are expressed as mean±S.E. from six tissue samples. One-way analysis of variance and Dunnett’s post hoc test were performed. ^#p<0.001 for TI-treated groups vs. control group. TI: soybean trypsin inhibitor. (C) Insulin and trypsin activity baseline data at the beginning of the experiment. The linear regression equation for predicted levels of insulin outflow is as follows: predicted levels of insulin outflow=9.208-(2.114×trypsin activity). Each open circle represents an individual value.

Effect of 10 μg/ml TI on amylase and lipase outflow. (A, B) Amylase outflow. (C, D) Lipase outflow. Each bar indicates data for tissues from six rats. Data are expressed as mean±S.E from six tissue samples. Left bar is the control group and right bar is TI-treated groups. Left side (A, C) is the data at baseline. Right side (B, D) is the data at the end of the experiment. Comparison of two groups was also performed using Student’s t-test [amylase: baseline (A): p=0.107; end of the experiment (B): p=0.361; lipase: baseline (C): p=0.988; end of the experiment (D): p=0.985]. Lipase and amylase outflow were plotted to examine the data at baseline (E) and the end (F) of the experiment. Each open circle represents an individual value. (F) The linear regression equation for predicted levels of lipase outflow was as follows: predicted levels of lipase outflow=0.341+ (0.209×levels of amylase outflow). TI: Soybean trypsin inhibitor.

Stereomicroscopic features of the pancreas stained with red mercurochrome. The pancreas was incubated without red mercurochrome dye for 1 h (A) and 3 h (B). The pancreas was incubated with red dye diluted 30-fold (low concentration) for 1 h (C) and 3 h (D). The pancreas was incubated with red dye diluted 6-fold (high concentration) for 1 h (E) and 3 h (F). Scale bar: 5 mm.