Calcification XIX. Calcification of Transplanted Rachitic Bone.

Summary Calcification of the rachitic metaphysis, with typical silver line test, was obtained in tibial slices that were transplanted to rats on a normal diet. Similar transplants to rats on a rachitogenic diet did not calcify. This difference was probably due to the higher Ca x P product in the body fluids of animals on a normal diet as compared to the product of animals on a rachitogenic diet. In vitro calcification was obtained in the sera of normal animals, in the sera of rachitic animals to which phosphate was added to raise the Ca x P product but not in the unmodified sera of rachitic animals. In vitro calcification was obtained in inorganic solutions with a Ca x P product of 50 but not with a Ca x P product of 20. Transplanted deep freeze stored bone slices treated with calcium chloride prior to deep freeze calcified more intensively than deep freeze stored bones not treated with calcium, as measured by the silver line test. Calcification in vitro studies indicated reversible inactivation of calcifiability of stored frozen bone which could be prevented or restored by calcium chloride treatment. While differences existed, calcification of the deep freeze stored bone indicated that there was a partial restoration of the calcifying mechanism or that some unknown ingredient exists in the body fluids which, if present, could have elicited restoration of the calcifying mechanism. Transplantation of rachitic bone, as proposed, may be an additional method for studying the differences of the actual body fluids on calcification of a given rachitic bone, or after treatment of such bone the changes in calcifiability with an actual standard body fluid such as that of an animal on a normal diet.