Metabolism of Proteins by Progeny of Underfed Mother Rats

Abstract

Fifty percent dietary restriction during gestation and lactation was reported previously to result in permanent growth-stunting of the progeny, even though they were offered an adequate diet ad libitum after weaning. Progeny from restricted mothers also showed reduced feed efficiency, low nitrogen balance and abnormal urinary nitrogen distribution. Nitrogen utilization has now been further studied by feeding the progeny from unrestricted and restricted mothers diets containing protein of different nutritive quality — egg albumin, Alpha-Protein and casein in successive periods. The restricted progeny utilized a good-quality protein as efficiently as the unrestricted progeny, for example, egg albumin, but they did not utilize a poorer quality protein such as soy protein or even casein. The specificity of abnormal urinary nitrogen distribution in progeny from restricted mothers was demonstrable after feeding the animals diets containing proteins of different quality and quantity, and also in a diet of low caloric level. Qualitative as well as quantitative analysis of urinary amino acids showed the restricted progeny excreted more free basic amino acids such as arginine, and significantly more total amino acids than the normal ones.