Increase in pancreatic lipase and trypsin activity and their mRNA levels in streptozotocin-induced diabetic rats.

The pancreatic lipase and trypsin activities in streptozotocin-induced diabetic rats were determined as well as the relative levels of mRNA coding for these proteins. It was found that after development of diabetes, the activities of pancreatic lipase and trypsin were significantly increased by 105% and 52%, respectively, accompanied by an increase in the levels of lipase and trypsinogen mRNA by 98% and 49%, respectively, while amylase activity and its mRNA were significantly decreased. The alteration of lipase, trypsin, and amylase activities and their mRNA in diabetic rats were all normalized by replacement of insulin. It is concluded that in the diabetic situation, the pretranslational control for pancreatic lipase and trypsinogen is stimulated, resulting in high levels of these enzymes in the diabetic rat.