Pfleiderer G, Mössner E, Schenk R
Histochemistry. 1984;80(2):145-8. doi: 10.1007/BF00679988.
Human kidney contains two antigenetically distinct isoenzymes of alkaline phosphatase (AP): a liver type and an intestinal type. The intestinal type AP is a minor component (1%-4%) of the total AP activity: it is found only in the cytoplasm. Both isoenzymes are located, found by an immunohistochemical technique, in the proximal convoluted tubules. This histochemical result eliminates the possibility that the low intestinal AP content in the kidney might only originate from blood vessels, where the intestinal isoenzyme was also found. The renal isoenzymes contribute to urinary AP. Intestinal type AP in urine of healthy persons, 10%-40% of the total AP activity, was found after high speed centrifugation predominantly in the supernatant (100,000 g), the liver type mainly in the sediment. Biochemical characterization revealed that intestinal type AP in kidney and urine are identical and differ from the isoenzyme of intestinal mucosa only slightly in their electrophoretic mobility.
人肾含有两种抗原性不同的碱性磷酸酶（AP）同工酶：肝型和肠型。肠型AP是总AP活性的次要成分（1%-4%）：仅存在于细胞质中。通过免疫组织化学技术发现，两种同工酶均位于近端曲管中。这一组织化学结果排除了肾脏中低含量肠型AP可能仅源自血管（在血管中也发现了肠型同工酶）的可能性。肾脏同工酶对尿AP有贡献。健康人尿液中的肠型AP占总AP活性的10%-40%，高速离心（100,000g）后主要存在于上清液中，肝型主要存在于沉淀物中。生化特性表明，肾脏和尿液中的肠型AP是相同的，并且在电泳迁移率方面与肠黏膜同工酶仅略有不同。
