Effects of caffeine on the growth of mandible and long bone in protein-energy malnourished newborn rats.

Rat dams with eight pups each were divided into six groups upon delivery; the first three were fed 6, 12 or 20% protein diets, and the second three the same diets but with caffeine added in the amount of 2 mg/100 g body wt. At Day 15, randomly selected pups were injected with [14C]proline to determine collagen synthesis of mandible and long bone. Other pups were used to determine the calcium content of these bones. The body, mandibular, and long bone weight of the pups whose dams were fed the 6% protein diet with caffeine increased compared to the noncaffeine group. Calcium content of the mandible and the collagen synthesis of the long bone were also increased. However, calcium content of long bone, collagen synthesis of mandible, and hydroxyproline content of mandible and long bone showed no difference between the caffeine and noncaffeine groups. In the pups whose dams were fed the 12% protein diet with caffeine, body and mandibular weight, collagen synthesis, and hydroxyproline and calcium contents in mandibles and long bones of pups showed no difference from those of the noncaffeine group, but long bones were heavier. In the pups whose dams were fed the 20% protein diet with caffeine, the body and long bone weight and hydroxyproline and calcium contents of the long bone of pups were lower than those of the noncaffeine group. Mandibular weight, calcium content, and hydroxyproline showed no difference between caffeine and noncaffeine animals, but collagen synthesis of the mandible was increased. Current data indicate that nutritional state and caffeine intake of the mother have a close relation to growth and development of the offspring.