Introduction
- Definition : serum inorganic phosphorus <0.80 mmol/l.
- Phosphate is a major intracellular anion. It has a structural role in cell membranes, hydroxyapatite of bone, nucleic acids and phosphoproteins including adenosine triphosphate (ATP). Important in oxygen transports (2,3-diphosphoglycerate), second messenger systems (cyclic adenosine monophosphate), coenzyme systems (nicotinamide adenine dinucleotide phosphate). Important in the regulation of protein, fat and carbohydrate metabolism. Involved in the activation of vitamin D and calcium homeostasis.
- Phosphorus exists as organic (phospholipids, phosphate esters) and inorganic (orthophosphoric acid, pyrophosphoric acid) forms. 80-85% of total body phosphate is inorganic in bone as hydroxyapatite. 15% is organic and in soft tissues. Most serum phosphorus is inorganic orthophosphoric acid. 10-20% of inorganic is protein bound. 80-90% is free or bound to magnesium, sodium and calcium.
- <1% of Total Body Phosphate found as extracellular active forms with only 33% of this being ionized.
- Total Body Phosphate levels closely regulated in conjunction with calcium.
Diagnosis
Clinical signs
- See Presenting Signs.
Sources
Publications
Refereed papers
- Recent references from PubMed.
- Schropp D M, Kovacic J (2007) Phosphorus and phosphate metabolism in veterinary patients. J Vet Emerg Crit Care 17 , 127-134.
Other sources of information
- Marino P (2007) Renal and Electrolyte Disorders: Calcium and Phosphorus. In: The ICU Book.pp 639-655. Lippincott, Williams & Wilkins.
- DiBartola S P, Willard M D (2006) Disorders of Phosphorus: Hypophosphataemia and Hyperphosphataemia. In: Fluid, Electrolyte, and Acid-Base Disorders in Small Animal Practice.pp 195-209. Ed. S DiBartola, Saunders Elsevier.
- Macintire D K, Drobatz K J, Haskins S C, Saxon W D (2005) Endocrine and Metabolic Emergencies In: Manual of Small Animal Emergency and Critical Care Medicine.pp 331-333. Lippincott, Williams & Wilkins.
