biotransformation of benzo[a]pyrene (bap) in the presence of microsomal fractions derived from liver and epiderm of adult and weanling rats was examined. the aim of this study was to evaluate the effect of age on the capacity of two organs in transformation of bap. subcellular fractions were prepared from skin and liver by ultracentrifugation and were used as the source of bap metabolizing enzy...

Augmenter of liver regeneration (ALR) is a hepatotrophic protein originally identified by bioassay in regenerating rat and canine livers following partial hepatectomy and in the hyperplastic livers of weanling rats, but not in resting adult livers. The ALR gene and gene product were subsequently described, but little is known about the cellular/subcellular sites of ALR synthesis in the liver, o...

The effect of unilateral nephrectomy on the number of cortical kidney cells undergoing DNA synthesis and mitosis was meas ured by tritiated thymidine autoradiography in both weanling and adult rats. Among the unoperated control animals, the weanling rat group showed a base line labeling index of 0.59%, and the adult animals, one of 0.11%. The response to unilateral nephrectomy resulted in a pea...

OBJECTIVE The contribution of antecedent viral infection to the development of type 1 diabetes in humans is controversial. Using a newer rat model of the disease, we sought to 1) identify viruses capable of modulating diabetes penetrance, 2) identify conditions that increase or decrease the diabetogenicity of infection, and 3) determine whether maternal immunization would prevent diabetes. RE...

When weanling rats are reared on a fat-free diet for about 10 weeks they develop, as originally shown by Burr & Burr (1929), certain signs of a nutritional deficiency. The signs can be cured or prevented by the inclusion of essential fatty acids (EFA), as linoleic acid, in the diet and the condition is therefore termed EFA deficiency. The weanling male rat has been used extensively in studies c...

Developmental changes in expression of ƒ¿-tocopherol transfer protein (ƒ¿-TTP) after birth were investigated using rats with respect to plasma changes of tocopherols. The expression of ƒ¿-TTP in the neonatal rat liver, which was very low immediately after birth, increased steadily during the two weeks of life before weanling and reached the adult level at four weeks. During the suckling period,...