Effect of maternal dietary amino acid pattern on rat offspring.

The effect of lifetime feeding to gravid rats of diets containing different indispensable amino acid patterns on body and brain composition of the offspring was studied. Two groups of rats were fed, from weaning to delivery, either experimental diet B or diet I. Both diets contained the same amount of total nitrogen (3.14%), available lysine (0.4%) and "complete protein to total protein ratio" (22.5%), but whereas diet I provided an excess of indispensable amino acids over the amount of limiting amino acid, diet B supplied all of the indispensable amino acids in marginal amounts and in a rather well balanced pattern. The nitrogen content of diet B was matched to the nitrogen content of diet I by addition of a mixture of dispensable amino acids. A control group fed stock diet (C) was run simultaneously. Birth body weight, carcass nitrogen to water ratio, and brain weight of pups were significantly lower in B than in I. The figures for I were not significantly different from the controls. Brain DNA content in B was significantly lower than in C, but in I it was lower than for both B and C. Nitrogen to water ratio and brain DNA content of group B were low when compared to the standard curves for our colony; however, DNA content was normal for the degree of body development. On the other hand, in group I brain DNA was preferentially affected, as if body and brain maturity were dissociated.