Glutamine, considered to be a non-essential amino acid during health, becomes a “conditionally essential” amino acid during conditions of catabolic stress. Despite this, very little is known about glutamine nutrition during pregnancy and lactation, two conditions which exert a catabolic stress upon the mother. Hypothesis: Dietary glutamine deprivation during pregnancy results in detrimental consequences for the fetus or pregnant mother and/or metabolic adaptations designed to meet their nutritional needs. Methods: Adult female rats were randomized to receive a diet containing no glutamine or glutamate or a diet containing a normal amount of glutamine (4% glutamine by weight, 0% glutamate). The diets were made isonitrogenous by the addition of nonessential amino acids. The experimental diet was initiated on the day the females were introduced to males for breeding. Diets were continued until day 20 of gestation, when fetal and maternal tissues were harvested for analysis. Results: Weights, litter size and glutaminase (GA) and glutamine synthetase (GS) activities are seen in the following table:

Table 1

Interpretation of Results: These results suggest that glutamine deficient mothers gain less weight and have smaller litter sizes that their glutamine sufficient controls. The changes in maternal liver GS and lung GA and fetal liver, lung and small intestine GA suggest an adaptive response to glutamine deficiency.