Comparative study of human placental and fetal brain alkaline phosphatase
Chatterjee, T.K.; Banerjee, P.; Banerjee, S.K.; Ghosh, J.J.
Indian Journal of Biochemistry and Biophysics 16(5): 268-272
1979
ISSN/ISBN: 0301-1208 PMID: 540932 Document Number: 148093
Significant alkaline phosphatase activity was found in human placenta and fetal brain tissues. The enzyme is present in cytosol and in microsomal fractions with a relatively higher activity in the latter fraction. The activity of the enzyme in the tissues shows a progressive increment with gestational age of the tissues shows a progressive increment with gestational age of the tissues; the term placental tissues does not register any further increase in the enzyme activity. In contrast to fetal brain, the placental enzyme demonstrates varying degrees of heat-stability depending on the gestational age of the tissue with preponderance after 14 wk. Both fetal brain and placental enzymes demonstrate a characteristic activation after pre-exposure at pH 5.0; after 14 wk the placental enzyme cannot demonstrate such acid-pH-induced activation. Dialyzed enzyme preparation of both the tissues can demonstrate acid-pH-induced activation phenomena only when the pre-exposure is carried out in the presence of inorganic orthophosphate where arsenate acts as an inhibitor.