Lipase is a water-soluble enzyme synthesized by the human body for the digestion, dissolution and fractionation of neutral fats.
This enzyme is produced by a variety of organs and tissues, which makes it possible to distinguish:
- pancreatic lipase;
- lingual lipase( produced by glands located in the mouth of infants);
- liver lipase;
- intestinal lipase;
- lipase of the lungs.
The main functions of lipase in the human body
- 4 The decreased level of lipase in the blood
- 5 The requirements for the analysis of lipase
The main functions of lipase in the human body
Lipase of any type is produced by the body for processing,and dividing into fat fractions. Nevertheless, the most important enzyme, which provides timely and complete digestion of lipids, is pancreatic lipase. This enzyme is excreted into the gastrointestinal tract( into the duodenum), as an inactive enzyme - prolipase. The transformation of a substance into an active lipase results from the action of bile acids and another enzyme produced by the pancreas - colipase. Typically, the pancreatic lipase( the so-called pancreatic lipase) affects the fats previously emulsified with hepatic bile. In turn, the gastric lipase is responsible for splitting the tributyrin of the oil, the lingual for splitting the fats of breast milk, and the hepatic for the cleavage of chylomicrons, low-density lipoproteins, and for regulation of the plasma lipids content.
In addition, lipase promotes the assimilation of vitamins A, D, E, K, polyunsaturated fatty acids and participates in energy metabolism.
The norm of lipase in the blood
The acceptable level of lipase in serum in women and men does not differ significantly. In particular, the content of the enzyme in the blood is considered to be adequate:
- for adults( persons who have reached the age of eighteen) - from 0 to 190 units / ml;
- for children under 17 years - from 0 to 130 units / ml.
Increased level of lipase in the blood
The main diagnostic value in the human body is pancreatic lipase, which is the main marker of pancreatic diseases. With the development of this or that pathology of this body, the level of lipase in the serum increases severalfold. In particular, an elevated level of lipase in the blood is noted with:
- acute pancreatitis;
- exacerbations of chronic pancreatitis;
- appearance of pancreatic tumors;
- of biliary colic;
- chronic course of gallbladder disease;
- intrahepatic cholestasis;
- intestinal obstruction;
- perforation of the hollow internal organ;
- intestinal infarction;
- cyst or pseudocyst of the pancreas;
- metabolic disorders( eg, with gout, diabetes, or obesity);
- chronic or acute renal failure;
- perforated stomach ulcer;
- taking a number of medications( narcotic analgesics, heparin, barbiturates, indomethacin);
- is an epidemic parotitis accompanied by a pancreatic lesion.
Occasionally, the causes of lipase activation are broken bones and other injuries. However, enzyme-level jumps are not a specific symptom for disparate physical injuries, so during the diagnosis of injuries, the results of lipase tests are not used.
In most cases, an increase in the level of lipase in the blood serum caused by diseases of the pancreas is accompanied by a synchronous increase in amylase, a digestive enzyme that breaks down starches to oligosaccharides. Meanwhile, the normalization of these markers in the process of recovering the patient does not occur simultaneously: pancreatic amylase returns to adequate values much faster than lipase.
Special studies have shown that the activity of lipase in the blood of persons suffering from pancreatitis in the first day of the disease is only moderately raised and very rarely reaches a level at which diagnosis can be considered reliable. As a rule, it is possible to detect a change in the level of lipase activity only on the third day of the disease. In particular:
- with edematic form of the disease, lipase levels do not go beyond the norm;
- for fatty pancreatic necrosis a moderate increase in lipase activity is recorded;
- with hemorrhagic pancreatic necrosis the level of lipase exceeds the norm by 3.5 times.
In this case, in normal the increased activity of the enzyme persists for 3-7 days from the day of development of the inflammatory process and begins to decrease only after 1-2 weeks. In turn, the prognosis of pancreatitis is considered unfavorable if the level of lipase in the serum increases tenfold or more, and within a few days does not decrease to a threefold excess of the norm.
Low blood lipase level
The level of lipase in the blood can decrease with any cancer( except for pancreatic cancer), as well as an excess of triglycerides in the body, that is, with improper, fat-suppressed nutrition or hereditary hyperlipidemia. In addition, a deficiency of this enzyme may indicate the transition of pancreatitis into a chronic form.
Requirements for the assay for lipase
The degree of lipase activity is determined based on a laboratory blood test taken from the patient from the vein in the morning, on an empty stomach. The patient should be warned that during the twelve hours preceding sampling, he is not recommended to eat any spicy, sharp and fatty foods and dishes. Meanwhile, in case of emergency, the analysis for lipase is given regardless of the time of day and the preliminary preparation.
Recently, two methods of establishing lipase activity have been widely used: enzymatic and immunochemical. In this case, the enzymatic is used much more often because it allows to significantly reduce the time spent for the analysis, as well as does not require a high-level laboratory staff to qualify.