Previous work in our laboratory has demonstrated impairment of cardiopulmonary reflex control of renal sympathetic nerve activity (RSNA) during the newborn period. The present study was designed to test the hypothesis that this delayed maturation is secondary to incomplete central integration of vagal afferent input. Term fetal (135-140 days; n = 6), newborn (3-7 days of age; n = 8), and young ...

Chronic oxygen exposure in the newborn rat results in lung isoprostane formation, which may contribute to the pulmonary hypertension evident in this animal model. The purpose of this study was to investigate the pulmonary arterial smooth muscle responses to 8-iso-prostaglandin F(2alpha) (8-iso-PGF(2a)) in newborn rats exposed to 60% O2 for 14 days. Because, in the adult rat, 8-iso-PGF(2alpha) m...

The use of newborn or immature animals in biomedical research poses certain challenges, in that the ecological niche of immature animals differs from that of adults, and the stimuli provided to immature animals can have profound physiological and behavioural effects through adulthood, even at the cerebral level. In particular, the newborn's behaviour and physiology are regulated by olfactory, t...

1. Immunologic function, growth, and longevity of neonatally thymectomized mice was restored by intraperitoneal administration of 100 to 400 million syngeneic, hemiallogeneic, or ailogeneic thymus cells from newborn or adult donors. Assays of the graft versus host capabilities of spleen cells from the animals restored with allogeneic cells showed that their immunologically competent cells are o...

The role of the kidney in foetal erythropoiesis was studied in newborn SD mice on the day of birth. Some of the homozygotes and heterozygotes of this strain are born anephric. Red cell production was evaluated by haematocrit levels, reticulocyte counts, and Fe-uptake in liver and RBC, the isotope given to the mothers during pregnancy. Erythropoiesis of the newborn with renal agenesis was not di...