lingual lipase

Lingual lipase starts the digestion of the lipids/fats.

Lingual lipase.

It secretes lingual lipase.

Gastric lipase, together with lingual lipase, comprise the two acidic lipases.

Digestion of some fats can begin in the mouth where lingual lipase breaks down some short chain lipids into diglycerides.

An additional enzyme, lingual lipase, hydrolyzes long-chain triglycerides into partial glycerides and free fatty acids.

Studies have shown that even in these cases, lingual lipase is present in normal amounts, and contributes to greater than 90% of total lipase activity in duodenum.

These glands are located around circumvallate and foliate papillae in the tongue, and they secrete lingual lipase, beginning the process of lipid hydrolysis in the mouth.

The proposed mechanism of lingual lipase preferentially cleaving short and medium chain triacylglycerols provides a means for absorption without the need for micelle formation and chylomicrons.

However, due to the unique characteristics of lingual lipase, including a pH optimum 4.5 -5.4 and its ability to catalyze reactions without bile salts, the lipolytic activity continues through to the stomach.

Lingual lipase, which is secreted by the acinar cells of the sublingual gland, has a pH optimum 4.0 so it is not activated until entering the acidic environment of the stomach.

This fact, in combination with the bile salt deficiency and low pH throughout the gastrointestinal tract of the neonate, demands that lingual lipase be the main enzyme catalyzing the hydrolysis of dietary fat.

Fat digesting lingual lipase in adult saliva can also help infant digestion and fat absorption since infants generally do not produce enough of these enzymes in their digestive tracts to efficiently process the fats they consume.

The hydrolysis of the dietary fats is essential for fat absorption by the small intestine, as long chain triacyglycerides cannot be absorbed, and as much as 30% of fat is hydrolyzed within 1 to 20 minutes of ingestion by lingual lipase alone.