ORGAN-SELECTIVE GROWTH IN THE OFFSPRING OF PROTEIN-RESTRICTED MOTHERS

Recent epidemiological studies in people whose birth weights were reco rded many years ago suggest links between impaired growth during early life and the development of diseases, including diabetes, much later in Life, The long-term effects of retarded early growth are proposed t o result from malnutrition at critical periods of fetal or infant deve lopment leading to reduction in the growth of organs and permanent cha nges in their metabolism or structure, or both, In order to investigat e this, a rat model was established which involved feeding either a di et containing 200 g protein/kg or an isoenergetic diet containing 80 g protein/kg to pregnant and lactating rats, In addition, cross-fosteri ng techniques were employed which allowed a separate evaluation of the prenatal or the postnatal periods. The offspring were studied at 21 d of age or were weaned onto a normal laboratory chow and studied at 11 months of age, The 80 g protein/kg diet during pregnancy did not affe ct the overall reproductive performance although more subtle differenc es were evident, Permanent growth retardation was evident in offspring subjected to maternal protein restriction during the postnatal period , At 21 d of age the offspring of protein-restricted mothers exhibited selective changes in organ growth: compared with the body weight, the lung and brain experienced a smaller decrease in weight; the heart, k idney and thymus decreased proportionately; whereas, the pancreas, spl een, muscle and liver showed a greater reduction in weight, In older a nimals the muscle weight was lower in the male rats and the relative w eight of pancreas was increased in the female rats.