ALP isoenzymes

Alkaline phosphatase includes a group of enzymes that catalyze the the hydrolysis reaction of inorganic phosphates.

Alkaline phosphatase is found in the cell membranes of many tissues, but the highest concentrations are found in bones, liver, renal tubules and intestinal mucosal cells.
ALP exists in the form of several isoenzymes: bone, liver, biliary, intestinal and placental.
The serum of adults contains mainly the hepatic isoenzyme (50%), with smaller amounts of bone isoenzyme (30%) and intestinal (20%) Bone isoenzyme predominates mainly in children and adolescents during the growth period of the body.
Blood serum of pregnant women contains placental isoenzyme accounting for about 48% of total ALP.
High values of placental isoenzyme are found in cancer of the bronchial cancer, colorectal cancer, in primary liver cancer, cancer of the cervix, cancers of trophoblastic origin.
Physiological ALP is elevated in premature infants, in the serum of children during puberty, and in women in the second and third trimesters of pregnancy. A pathological increase in activity is observed primarily primarily in liver diseases that progress with cholestasis (stasis of bile), cholangitis, viral hepatitis, liver tumors, bone diseases (rickets, osteomalacia, vitamin D3 deficiency, tumors), hyperparathyroidism.
Decreased ALP activity occurs in hypophosphatemia (a disorder of An autosomal recessive disorder characterized by abnormalities in the calcification of bones; calcium and phosphorus concentrations are normal), disorders of bone growth (achondroplasia, cretinism, ascorbic acid deficiency ascorbic acid deficiency).