Alkaline Phosphatase: An Overview

Abstract

Alkaline phosphatase (ALP; E.C.3.I.3.1.) is an ubiquitous membrane-bound glycoprotein that catalyzes the hydrolysis of phosphate monoesters at basic pH values. Alkaline phosphatase is divided into four isozymes depending upon the site of tissue expression that are Intestinal ALP, Placental ALP, Germ cell ALP and tissue nonspecific alkaline phosphatase or liver/bone/kidney (L/B/K) ALP. The intestinal and placental ALP loci are located near the end of long arm of chromosome 2 and L/B/K ALP is located near the end of the short arm of chromosome 1. Although ALPs are present in many mammalian tissues and have been studied for the last several years still little is known about them. The bone isoenzyme may be involved in mammalian bone calcification and the intestinal isoenzyme is thought to play a role in the transport of phosphate into epithelial cells of the intestine. In this review, we tried to provide an overview about the various forms, structure and functions of alkaline phosphatase with special focus on liver/bone/kidney alkaline phosphatase.

Reporting the toxicological profile of methanolic leaf extract of <i>Anthocleista vogelii</i> Planch on Wistar rats

“…Again, ALP activity, which is primarily localized in membranes of osteoblastic cells of bones, mammary gland, placental, intestinal mucosa, renal proximal tubules and hepatocytes, where it functions in the alkaline hydrolysis of organophosphates to maintain biological membrane integrity. (Ramaiah, 2007;Dzoyem et al, 2014;Sharma et al, 2014). Thus, Dzoyem et al (2014); Ogbe et al, (2012); Vasudevan and Sreekumari (2007) examined comparatively, the toxicological relevance of ALP activity as a useful indicator of cholestasis and hepatobiliary injury, while ALT and AST activities were essential biomarkers employed for biomonitoring of hepatocellular damage when biological organisms are exposed to stressors From the present study, Table 2 showed increasing serum AST, ALT and ALP activities without significant impact (p > 0.05) among treatment groups relative to control group on exposure to methanolic leaf extract of the plant, suggesting that there was no damage to hepatocyte and renal tissues.…”

Біохімічні Маркери Сироватки Крові У Кроликів Після Поперекового Експериментального Задньобічного Спондилодезу З Використанням Автологічного Фібрину, Збагаченого Тромбоцитами

“…Низкая средняя величина отношения кальций/ фосфор в контрольной группе 1 (декортикация по-перечных отростков без использования костно-пла-стического материала) косвенно отражает начальные стадии минерализации в зоне формирующегося кост-ного сращения. Начальные стадии процесса минерализации кост-ной ткани связаны с активацией неспецифичного изофермента щелочной фосфатазы, которая расщеп-ляет органические фосфорсодержащие соединения, увеличивая локальную концентрацию ионов фосфора в везикулах экстрацеллюлярного матрикса до точки насыщения [18]. Щелочная фосфатаза, синтезируе-мая остеобластами, является маркером последних, и ее концентрация в клетках костной ткани коррелирует с их потенциалом минерализации [5], а содержание в плазме крови является информативным показателем костного ремоделирования [15,18].…”

Sustained release of Semaphorin 3A from α-tricalcium phosphate based cement composite contributes to osteoblastic differentiation of MC3T3-E1 cells

“…ALP is a membrane bound enzyme and responsible for the mineralization of extracellular matrix during differentiation of osteoblast and the formation of new bone [32], and is regarded as an important marker of the differentiation of osteoblast. Figure 5(a) reveals the ALP activities of the different groups.…”