Ptyalines

Ptyalines, also known as ptyalin, refers to the salivary amylase enzymes produced in the saliva of many animals, including humans. In humans, the principal enzyme is salivary alpha-amylase, secreted mainly by the parotid glands with additional contributions from the submandibular and sublingual glands.

Functionally, ptyalin catalyzes the hydrolysis of starch and glycogen by breaking 1,4-alpha-glycosidic bonds, producing maltose, maltotriose, and dextrins. This activity initiates carbohydrate digestion in the mouth, although subsequent digestion depends on pancreatic enzymes in the intestine.

Properties of ptyalin include that it is a calcium-dependent metalloenzyme with optimal activity near neutral pH, typically around 6.7 to 7.0. It is inactivated by acidic conditions, such as those found in the stomach, which limits its activity to the oral cavity and shortly after swallowing.

Occurrence varies among species and individuals, but salivary amylase activity is a common feature of mammalian saliva. The term ptyaline has historical usage and is often encountered in older physiological literature; it is broadly synonymous with salivary amylase.

Clinical notes: Salivary amylase activity can be measured in research or diagnostic contexts. In clinical practice, elevations of amylase in serum are more commonly associated with pancreatic sources rather than salivary, whereas salivary amylase activity itself is not typically a diagnostic marker for disease. Etymology: the name derives from Greek ptyalon, meaning saliva.