PREECLAMPSIA IS ASSOCIATED WITH AN INCREASE IN TROPHOBLAST GLYCOGEN-CONTENT AND GLYCOGEN-SYNTHASE ACTIVITY, SIMILAR TO THAT FOUND IN HYDATIDIFORM MOLES

Pre-eclampsia is a placental disorder, but until now, biochemical deta ils of dysfunction have been lacking. During an analysis of the oligos accharide content of syncytiotrophoblast microvesicles purified from t he placental chorionic villi of 10 primigravid women with proteinuric pre-eclampsia, we found an excess of glycogen breakdown products. Furt her investigation revealed a 10-fold increase in glycogen content (223 +/-117 mug glycogen/mg protein), when compared with controls matched f or gestational age at delivery (23+/-18 mug glycogen/mg protein) (P < 0.01). This was confirmed by examination of electron micrographs of ch orionic villous tissue stained for glycogen. The increase in glycogen content was associated with 16 times more glycogen synthase (1,323+/-1 ,013 relative to 83+/-96 pmol glucose/mg protein per min) (P < 0.001), and a threefold increase in glycogen phosphorylase activity (2,280+/- 1,360 relative to 700+/-540 pmol glucose / mg protein per min; P < 0.0 5). Similar changes in glycogen metabolism were found in trophoblast m icrovesicles derived from hydatidiform moles. Glycogen accumulation in villous syncytiotrophoblast may be a metabolic marker of immaturity o f this cell which is unable to divide. The implications of these findi ngs with regard to the pathogenesis of re-eclampsia are discussed.