Abdulqadir Khdir Hamad Msc. Medical Biology Practical Medical Physiology 2 nd stage

Alkaline phosphatase : is a hydrolase enzyme responsible for removing phosphate groups from many types of molecules, including nucleotides, proteins, and alkaloids. The process of removing the phosphate group is called dephosphorylation. As the name suggests, alkaline phosphatases are most effective in an alkaline environment.

Physiology In humans, alkaline phosphatase is present in all tissues throughout the entire body, but is particularly concentrated in liver, bile duct, kidney, bone, and the placenta. Humans and most other mammals contain the following alkaline phosphatase isozymes: ALPI – intestinal ALPL – tissue non-specific (liver/bone/kidney) ALPP – placental (Regan isozyme)

The liver, bone and kidney enzymes are different forms of the same gene product; the gut and placental forms are isoenzymes. Gut ALP rises after meals Bone ALP increases at the time of physiological growth. Placental ALP normally increases at the end of the third trimester.

Increased levels of plasma alkaline phosphatase include: hepatobiliary disease including: Cholestasis ( increase 10 times normal levels ) hepatocyte disease-viral hepatitis bone disease – increased bone isoenzyme of alkaline phosphatase, Paget's disease bone metastases primary bone tumour e.g. sarcoma recent fracture growing child - especially at puberty

N ORMAL L IVER

C IRRHOTIC L IVER

Reduced alkaline phosphatase 1.zinc deficiency 2.magnesium deficiency 3.hypophosphatasia 4.collection of blood in EDTA or oxalate anticoagulant 5.hypothyroidism 6.severe anaemia 7.pernicious anaemia 8.oestrogen replacement therapy in postmenopausal women 9.Wilson's disease 10. hypothyroidism in children 11.vitamin C deficiency

Procedure ALP