A phosphatase with an optimum pH of above 7.0 (e.g. ,8.6), present ubiquitously; localized cytochemically in membranesby modifications of Gomori's nonspecific alkaline phosphatase stain. Increased in: obstructive hepatobiliary disease, bonedisease (physiologic bone growth, Paget's disease, osteomalacia, osteogenic sarcoma, bone metastases),hyperparathyroidism, rickets, benign familial hyperphosphatasemia, pregnancy (third trimester), Gl disease (perforatedulcer or bowel infarct), hepatotoxic drugs. It hydrolyzes many orthophosphoric monoesters; low levels of this enzyme areseen in cases of hypophosphatasia.