Metabolic effects of a “carbohydrate-free” diet in the pregnant rat

Abstract

Abstrac The effects on selected metabolic indicators of carbohydrate deprivation in pregnant rats was studied. Pregnant rats were fed a diet containing 13% casein, either 69.5% (CON) or 0% (CD) carbohydrate, and oleic acid to make the diets isocaloric. Diets were fed beginning on Day 0 of pregnancy. A restricted intake group (RI) was also included to indicate the effect of reduced food intake. On days 8, 10, and 12 of pregnancy, animals were killed and liver, uterus and blood were harvested. Glycogen and glucose-6-phosphatase in endometrial tissue, glycogen in liver, ketone bodies in whole blood, and glucose, total lipid, cholesterol, urea nitrogen and alanine in plasma were determined. In CD dams, fetal resorption reached 75% by day 12 of gestation but only 35% in RI dams. Carbohydrate deprivation and restricted intake resulted in depleted liver glycogen. CD dams were hypoglycemic and hyperlipemic. Plasma alanine did not differ among the 3 groups and plasma urea was elevated in the CD group only on day 12. CD dams were markedly hyperketonemic. Neither uterine glycogen nor uterine glucose-6-phosphatase activity differed between the 3 groups, suggesting that uterine glycogen utilization was not the limiting factor in embryonic survival. Hypoglycemia, hyperketonemia or both may be related to the reproductive failure in CD rats.