Alkaline phosphatase isozymes of human fetal organs

Abstract

We have reported that the properties of alkaline phosphatase (ALP) from meconium, neonatal feces and human fetal intestine, were similar to that of adult intestine except for their electrophoretic mobilites and sensitivities to neuraminidase, and they were considered not as one of isozymes but as one of modified enzyme of adult intestinal ALP, which were caused by the different content of sialic acid in them.We studied the properties of ALP from human fetal organs which were obtained from 13 fetuses, using the same technique as reported previously.The results were as follows: 1) Fetal intestine showed the heighest ALP activity of all organs, and that of bone showed the next. The activity of ALP of ovarium, adrenal, kidney, liver, lung, and spleen showed moderate activity, while that of testis, brain and stomach showed low activity. 2) According to their enzymological and immunological properties, ALP from human fetal organs were divided into two groups; one was hepatic-type ALP (ALP from liver, bone, spleen and so on), and the other was intestinal-type ALP (ALP of intestine). 3) The activity of ALP of fetal intestine increased markedly, and that of fetal thymus increased slightly during fetal development. 4) The properties of ALP of each fetal organs were similar to those of adult ones but the activity of ALP of fetal bone and adrenal, and the electrophoretic mobility and sensitivity to neuraminidase of ALP of fetal intestine were different from adult ones.