Role of parotid amylase in starch digestion in the gastro-intestinal tracts of diabetic rats.

In order for the role of parotid amylase in starch digestion in the gastro-intestinal tracts of diabetic rats to be clarified, this study investigated the effect of parotid-duct ligation on both amylase secretion from the parotid glands and pancreas into the gastro-intestinal tract and on starch digestion in the gastro-intestinal contents during feedings. In both diabetic rats and control rats, parotid-duct ligation reduced amylase activity in both the parotid glands during fasting and in the gastric contents after feeding. The amylase activity in the intestinal contents after feeding was reduced by parotid-duct ligation in the diabetic rats. Starch digestion in the gastro-intestinal tract after feeding was reduced by parotid-duct ligation in the diabetic rats. The results suggest that most of the amylase activity in the gastric contents and a large part of the amylase activity in the intestinal contents are derived from the parotid glands, and that parotid amylase plays an important role in starch digestion in the gastro-intestinal tracts of diabetic rats.