Enzyme histochemical localisation of alkaline phosphatase activity in osteogenesis imperfecta bone and growth plate: A preliminary study

The normal human growth plates used in this study showed a similar pattern, but in the OI growth plate even the hypertrophic zone, where the alkaline phosphatase activity is reported to be high, showed less intense reaction product. Biochemical reports indicate that alkaline phosphatase levels are normal in cultured OI cell lines, yet ultrastructural histochemical observations reported here, show reduced enzyme localisation and this may suggest reduced amounts of protein or reduced activity at the tissue level.