Abstract
Despite the importance of the placenta for fetal homeostasis, energy and purine metabolism in developing versus ageing trophoblast has not been studied. We have developed methods for isolation and characterization of placental cells, and measured the apparent activities of 5′-nucleotidase and AMP-deaminase, key enzymes in adenine nucleotide catabolism, in 1st and 3rd trimester preparations. Trophoblastic cells were separated using 0,3% collagenase and 0,001% DNAase, followed by filtration and isopycnic centrifugation using Percoll (R). Over 95% of the cells banding at the density of ca. 1,02 g/ml were trophoblasts expressing cytokeratin but not vimentin intermediate filaments. The enzyme activities were measured in cell sonicates using 14-C-AMP as substrate with final concentrations 2 mM (AMP-deaminase) and 0,3 mM (5′-nucleotidase).
The activity of trophoblastic AMP-deaminase does not change with gestational age. Mean total activity of 5′-nucleotidase is higher in the 1st trimester trophoblast but individual placentae show large variation. Gestational age does not appear to be a major determinant of 5′-nucleotidase activity.
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Vettenranta, K., Raivio, K. KEY ENZYMES OF ADENINE NUCLEOTIDE CATABOLISM IN FIRST AND THIRD TRIMESTER HUMAN TROPHOBLAST. Pediatr Res 19, 1085 (1985). https://doi.org/10.1203/00006450-198510000-00106
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DOI: https://doi.org/10.1203/00006450-198510000-00106