Vitamin B 6 enzymes in normal and pre-eclamptic human placentae

Abstract

Placentae from normal and pre-eclamptic women were analyzed for their content of three enzymes: pyridoxal kinase, pyridoxal phosphate phosphatase, and pyridoxine phosphate oxidase. The range of values for the specific activities of the phosphatase in partially purified extracts was identical in both normal and preeclamptic placentae. The mean value was 6.4 × 10 −3 μmoles/min/mg protein for both tissues. The ranges of values for the specific activities of pyridoxal kinase and pyridoxine phosphate oxidase in the same extracts on the other hand were lower in preeclamptic placentae than in normal ones. The mean value in normal placentae was 1.52 × 10 −3 μmoles/min/mg protein for the kinase and 1.68 × 10 −5 μmoles/min/mg protein for the oxidase. In extracts of placentae from pre-eclamptic women these values were 1.23 × 10 −3 μmoles/min/mg protein and 1.29 × 10 −5 μmoles/min/mg protein respectively.