Levels of creatine kinase activity in cartilage of tubular and nontubular bone in relation to pathogenesis of achondroplasia.

For the purpose of investigating events of energy metabolism in growing cartilages of human tubular and nontubular bones, measurements of creatine kinase (CK), lactate dehydrogenase (LDH), and aldolase of freshly excised cartilages in normal and pathologic conditions were performed. The level of cartilage CK of the normal phalanges (tubular bone) and exostosis was significantly less than those of the normal iliac bones (nontubular bone) and the achondroplasia tubular bone. A similar difference was also found between the tubular and the nontubular bone of an autopsy subject with achondroplasia. There was no statistical difference in the levels of LDH and aldolase in the cartilage between the tubular and the nontubular bone. These observations together with results obtained from iliac and limb cartilages of the newborn rat suggest the hypothesis that CK activity of cartilage of the tubular and the nontubular bone is different; cartilage of achondroplasia tubular bone has CK activity similar to that of normal nontubular bone cartilage.