Dietary choline supplementation in pregnant rats increases hippocampal phospholipase D activity of the offspring

Supplementation with choline during pregnancy in rats causes a long‐lasting improvement of visuospatial memory of the offspring. The biochemical mechanism of this effect may be related to the function of choline as a precursor of phosphatidylcholine (PC), the substrate of a receptor‐stimulated enzyme, phospholipase D (PLD). PLD activation initiates the sequential formation of two intracellular messengers, phosphatidic acid and l,2‐sn‐diacyl‐ glycerol. We hypothesized that prenatal choline status may cause long‐term modulation of PLD‐catalyzed PC hydrolysis in the hippocampus, a brain region implicated in visuospatial memory functions. PLD activity was determined in hippocampal slices prelabeled with [ 3 H]glycerol or [ 3 H]oleic acid by measuring the PLD‐catalyzed formation of [ 3 H]phosphatidyl‐ propanol in the presence of 1‐propanol. Slices were obtained from male pups born to mothers consuming a control diet, a choline‐supplemented diet, or a choline‐free diet from days 11 to 17 of pregnancy. The radiolabeling of phospholipid classes was unaffected by the treatments. Prenatal choline supplementation significantly increased basal PLD activity in [ 3 H]glyc‐ erol‐labeled slices [by 46% of controls on postnatal day (P) 7 and by 36% on P21 ], and [ 3 H]oleate‐labeled slices (by 91 % on P7), as well as glutamate‐stimulated PLD activity in [ 3 H]oleate‐labeled slices (by 60% on P7). Prenatal choline deficiency failed to alter PLD activity. The actions of choline apparently required intact cells because in vitro assays of PLD activity in hippocampal homogenates, using fluorescent NBD‐ PC as substrate, revealed no differences between groups. The results show that prenatal choline supplementation up‐regulates basal and receptor‐stimulated PLD activity in the hippocampus during postnatal development.—Holler, T., Cermak, J. M., Blusztajn, J. K. Dietary choline supplementation in pregnant rats increases hippocampal phospholipase D activity of the offspring. FASEBJ. 10,1653‐1659(1996)