The effect of oxygen tension on collagen synthesis and calcium uptake in newborn rats' calvaria in vitro.

Using newborn rat calvaria, we determined the effects of oxygen tension on bone cell metabolism in vitro. Halved calvaria were incubated in medium either in air or after flushing nitrogen or oxygen and studied for collagen synthesis, calcium uptake, and DNA content. The percentages of DNA content, radioactive proline count in mg of bone tissue, and radioactive proline count combined with counts of medium and bone tissue in the nitrogen-exposed group were less than those of their pair-matched controls. Percent calcium counts per DNA and calcium uptake per mg of tissue were greater in the nitrogen-exposed group than in the pair-matched controls. In contrast, no difference was found in any measurements in the oxygen-exposed group compared with controls. It is concluded that collagen synthesis, in contrast to proline uptake, is not affected by low oxygen, whereas calcium uptake is greatly enhanced. Furthermore, low oxygen tension exerts a greater effect on bone cell metabolism than does the hyperoxic condition.