PREGNANCY AND LACTATION ARE ASSOCIATED WITH DIMINISHED CONCENTRATIONSOF CHOLINE AND ITS METABOLITES IN RAT-LIVER

Choline is an important nutrient that is actively transported from mot her to fetus across the placenta and from mother to infant across the mammary gland. Thus, pregnancy and lactation are times when dietary re quirements for choline may be increased. Pregnant rats eating AIN-76A diet (with and without choline) for 6 d (d 12-18 gestation) were compa red with nonmated female and male rats eating the same diets. Similarl y, lactating rats were compared with nonmated female rats, both groups eating these same diets for 25 d (gestation d 12-postpartum d 15). We measured choline and choline metabolites in livers on the last day of feeding. Nonmated female rats, eating the control diet, had higher he patic choline metabolites concentrations than did male rats (choline, 98%; betaine, 96%; and phosphorylcholine, 55% higher), pregnant rats ( phosphorylcholine, 47%; and betaine, 42% higher) or lactating rats (ph osphorylcholine, 49%; phosphatidylcholine, 37%; and betaine, 273% high er). We found that nonmated females eating a choline deficient diet ha d only a modest diminution (33%) of the labile choline metabolite PCho in liver, compared with similar rats eating a control diet. When comp ared with similar rats fed a choline-adequate diet, pregnant rats fed a choline-deficient diet had significantly greater diminution of hepat ic phosphorylcholine (88% lower) than did nonmated females. Liver phos phorylcholine was only 12% lower than in controls in nonmated females fed the deficient diet for the same 25-d period. Lactating rats were t he most sensitive to choline deficiency, with liver phosphorylcholine 88% lower than in similar rats fed control diet. Our data suggest that the nonpurified diet offered in the laboratory does not provide suffi cient choline to meet the extraordinary demands of pregnancy and lacta tion. The intake of extra dietary choline may be advantageous during p regnancy and lactation in rats.