SummaryThirteen Fischer strain rats were divided randomly into 3 groups soon after became pregnant and fed a 10%, 18%, or 36% casein diet throughout pregnancy and lactation. At weaning, female pups from the dams were divided into 3 further groups which were fed throughout life 10%, 18%, or 36% casein diet. The animals were weighed regularly and given a full autopsy after death. DNA was determined in the cerebrum and cerebellum of progeny at 7, 15 and 50 weeks of age respectively. The level of protein intake of the dams did not affect the litter-size, but did affect the body weight of pups at weaning. When fed a high protein diet after weaning, pups from dams fed a low protein diet weighed less throughout life than those from dams fed a high protein diet. A similar effect of protein intake was observed on the tail length. Pups of dams fed a low protein diet ate a larger amount of diet per unit body weight after weaning than those of dams fed at a high level of protein. Pups at 7, 15, and 50 weeks of age respectively from dams fed 10% casein diet had a lighter cerebrum and cerebellum than pups of the same ages from dams fed respectively 18% and 36% casein diet. They also had less total DNA in the cerebrum and cerebellum than the latter. At the ages of 1 and 2 years respectively, the survival rates of rats fed the same diet as their mothers tended to be greater than those of rats fed diet different from that of their mothers. They also tended to live longer than the latter: 4 of 60 rats lived for over 1,000 days, and 3 of these were fed the same diet as that of their mothers. Lesions observed at death did not differ in different groups. However, the incidence of lesions of the kidney and the number of tumors seemed to be greater in groups fed a high protein diet.

Nineteen healthy humans (2 men and 17 women) served as experimental subjects in 4 experiments using diets having different levels of leucine and also a valine-deficient diet. The effect of an excess intake of leucine, with and without addition of vitamin B-6, and the effect of a deficiency of valine on urinary excretions of N1-methylnicotinamide, N1-methyl-2-pyridone-5-carboxamide, nicotinic acid, quinolinic acid, and 5-hydroxyindole acetic acid, and on the level of plasma amino acids were investigated. There was no effect of leucine on the excretion of these metabolites, but a marked decrease in the plasma (or serum) valine level was observed. The same decrease was seen when a valine-deficient diet was fed.

The well known fact that the activity of delta-aminolevulinic acid dehydratase (ALAD: EC 4.2.1.24) is reduced in red cells of animals with lead poisoning was found to be upset, by using a modified method of Gibson's original procedure, for determination of activated ALAD activity. The modified method involves addition of 0.2 mM Zn2+ and then preheating the enzyme solution at 60 degrees C for 5 min before following Gibson's original procedure. With this methodological modification, the ALAD activity of erythrocytes of rats poisoned with lead was found increased. Furthermore, the enzyme was purified from the peripheral blood of lead-poisoned rats. ALAD protein in peripheral blood was also determined by single radial immuno diffusion using rabbit anti-serum raised against rat liver ALAD. As the result, the ALAD activity obtained from the modified method was found to be directly proportional to the absolute amount of enzyme proteins determined both by chemically and immunochemically. The modified method for measuring true ALAD content in blood cells in lead poisoning is more reliable than previous ones.

No abstract

No abstract