No abstract

Rats were growth-retarded either from conception to 5 postnatal days (FNR or ‘small-for-dates’ group) or from 5 to 25 postnatal days (IR group) by underfeeding their mothers or foster-mothers. All young were fed ad libitum from weaning till they were killed at 15–24 weeks. The body weight of the FNR rats was 36% less than that of controls at 5 days and remained significantly less throughout their lives. Their adult nose-rump and tail lengths were slightly but significantly shorter than those of controls, but they did not differ in total body fat. TR rats weighed less than control and FNR rats from 10 days onwards, and they were leaner than both groups at death. They grew more in nose-rump and tail length between 35 and 115 days than the other groups, but were still significantly shorter than the controls at 115 days. This ‘catch-up’ may be related to their relative skeletal immaturity (assessed radiographically) at the time of the body growth spurt. Brain growth was impaired in both FNR and IR rats, though in different ways. Cerebellar growth was selectively affected in IR but not in FNR rats. Total synaptosomal protein (a probable measure of synapse number) was lower in the brains of both experimental groups in proportion to their brain weight deficits.

No abstract

SUMMARY Rats were undernourished during the foetal and suckling periods by limiting maternal food intake. Animals were weaned to an unrestricted diet at 25 days of age. Before weaning, the mean plasma corticosteroid concentration in undernourished animals was 39 μg/100 ml compared with 21 μg/100 ml in well-fed controls. At 15–17 weeks of age previously undernourished and control animals did not differ in basal plasma corticosteroid concentration. After stressful stimulation, however, levels were lower in animals subjected to early undernutrition than in controls. It is suggested that nutritional deprivation in infancy resulting in increased plasma corticosteroid levels at that time, permanently modifies the adrenocortical response to stress.

Abstract— The concentration of ascorbic acid in whole rat brain during the first week of postnatal life was up to 100 per cent higher than in adult animals. A progressive fall in concentration occurred between 4 and 30 days of age. Corresponding changes did not occur in liver and adrenal gland, two other organs rich in ascorbic acid. Rats subjected to growth retardation during the fetal and suckling periods had, at 25 days of age, levels of ascorbic acid in the cerebellum and brainstem significantly higher than those of control animals. A period of prolonged asphyxia in 5‐day‐old rats resulted in a significant 4 per cent reduction in whole brain ascorbic acid concentration.