1. To evaluate the role of gestational protein-energy malnutrition on fetal hard-tissue growth and metabolism, we measured several variables in the growth centres of mandibles and long bones of newborn rats.2. Control pups and pups of malnourished dams had approximately the same extent of reduction in body-weight, mandibular weight and long-bone weight.3. The malnourished group had more cells in the mandible although cell size was the same as that of controls.4. In contrast, in the long bones, the malnourished group had fewer cells than did controls whereas cell size was unchanged.5. Calcium content was the same in long bones of both groups, but was less in the mandibles of pups from malnourished dams. Ca metabolism as measured by 45Ca uptake was unchanged in the long bones, but was increased in the mandibles of the malnourished group shortly after birth. Calcification patterns at birth in these bones correlated well with alkaline phosphatase (EC 3.1.3.1) activity.6. These findings indicate that the mandibles and long bones of offspring are affected differently by protein–energy malnutrition during the mother's gestation. Prenatal nutritional stress resulted in a disturbance of the pituitary–adrenal system. Increased adrenal corticosterone could possibly be related to the different observed changes in bone metabolism.
Growth of the Tooth Germ in Newborn Rats Exposed to Oxygen at Atmospheric and High Pressure
