Relationship between serum-amylase activity and intraductal pressures in the rat parotid and submandibular salivary glands after administration of pilocarpine or isoprenaline.

Ligation of the parotid ducts induced marked elevation of serum-amylase activity after administration of pilocarpine or isoprenaline. Secretion of saliva and serum-amylase activity increased most rapidly in the first 15 min after injection of pilocarpine, whereas isoprenaline induced a constant rate of secretion and serum-amylase activity over 120 min. Amylase activity in the serum was closely connected with intraductal pressure due to saliva secretion.